Thank you for much for posting this. Although this video is 4 years old, it helped me fix a Velodyne DPS-10 in December 2018. Your comment about old brown glue that become conductive was the key I needed. Simply cleaning the brown gunk was all it took to fix the subwoofer I got for free from my neighbor. Please keep up the good work!
YOUR AWESOME !! I have ct veyodyne bought it 35 years ago I love it there amazing. You saved it for me,so I wanted to thank you !! I didn’t blow the diode as yours the same part the plastic door looking thing had a spot came of so one drop solder I was up and running I guess 35 years glue hardens it cracks in that area & breaks that area free & starts shaken THXS MY FRIEND for posting your knowledge 😀 it made my Day
I just wanted to comment on this. I had a CHT-12 that wouldn't output at all. After watching this video I was able to scrape off the old, bad glue from the board and it starting working again! How long will it last, who knows, but for a free fix I am beyond elated! Thank you for making and keeping this video up.
Fascinating to watch your methods of troubleshooting, you (almost) always go straight to the issue, you definitely have a knack with audio electronics ! I wish you had time for online consultations about issues that we sometimes have but I realise that would eat up a LOT of your time and cause you endless difficulties.
Wow, I'm glad I saw this video! My DPS-10 was fine, but I wanted to check on the condition of the filter caps. They were OK looking, and I would have closed it back up if I hadn't seen this. However I looked down in the "heatsink valley" and found the same carbonized glue! In my case it had started eating through R802, not the diode. I removed all that I could with a long thin screwdriver and blew it out with compressed gas. Then I used the pointy q-tips you can buy at Mouser et al. and some alcohol to remove the rest of the carbon residue. I think r802, 6.3k, is just a bleeder resistor for the caps so I left it; getting to the board for soldering as seen in this video is a major hassle. That stuff is not only conductive, it's actually magnetic! It stuck to my magnetic screwdriver. Sub seems ok after re-powering...
I have the 10" version of this sub and have the exact same problem so was happy to see this video, gives me a good place to start looking on fixing it.
Great plumber ,very reasonable and honest ,definitely my new household plumber, 20 plus tears of experience,this guy knows his stuff! Worth a call-gives free estimates over phone!
Recap,I fixed it .3 bad lytics tested with esr meter.They were on the eq board that has the volume control and x over adjustments. They were in close proximity of the plus and minus 12v regulators/ no schematic location numbers . lm7912 and lm 7812 ICs. They were 10uf @ 50v ratings on the capacitors.Thought I would share my fix.Symptom was loud humming and motor boating sounds ,volume had no effect.Just full blast noise even if volume was at minimum. Jeff Velodyne hgs 15bg
I remember when i looked for a ham radio some time ago, and between many 1980-1990 radios made by Kenwood there was a common problem with this brown glue that started conduction into everything! Read many guides to clean everything and was a major thing to do to get the radio working properly!
You noted that the power output was a little low, I wonder if the speaker was in fact 4 ohms, not uncommon with a number of subs I have tested. As you did in fact use a 8 Ohm load this MIGHT account for the lower O/P. Just a thought!
Thanks for posting this video I just picked up a pair of these needing repair you would have thought whoever designed these would have put more thought into the mounting of the board to resist broken solder joints and maybe a better thermal solution good diagnostics and your part! Thank you
Awesome seeing you diagnose the issues like this. I'm still pretty new to this so getting an idea of how to troubleshoot circuits is very helpful. Thanks for posting! :)
You clearly have some skills. Thanks for the well done video. I found it while searching for some insight as to why my 14 year old Velodyne CT 150 is acting up. It powers up fine but is popping and snapping erratically. It seems to be a common problem for the CT series. Anyway, perhaps I'll take it apart to see if there is anything obvious.
Fascinating. Having the same issue with my velodyne where it trips the circuit breaker at 50% volume and I have to cycle it off and on. Wish I had the technical skills to fix this myself!
That back panel looks identical to an old Kenwood I just picked up. Same screws, heat sink, switches, cord, etc. The Velodyne internal boards are slightly different, slightly more modern looking and both on edge, but basically the same sizes and count and uses similar connectors, the Kenwwood has smaller 3300uF/50v main capacitors and no auxilary caps(the blue ones not mounted on the pcb) and they seem to have leaked.(I get very muddy sound or a pure 60 hz hum, based on how much I wiggle the adjustments)
I've been seeing that brown glue more and more. I had a nice Philips receiver that started having bizarre issues, including lots of hiss and sound leaking through the different modes (ie, if it was set on CD, you'd faintly hear something connected to the Tape input). Ended up finding that brown glue all over a bunch of logic components, with measurable resistance connecting low voltage logic parts to the +70vDC supply cap. Really wasn't worth fixing, but the it was a real power house (I was able to load the transformer secondary to over 450 watts without the voltage sagging at all, not sure if the output transistors could take it though). Luckily, they had designed it in a modular way, so the main amp section was completely self-powered by the +/- 70v Rail, with a simple 4 pin header on the input stage. So I gutted the control electronics, and just hooked up a set of RCA jacks right to the amp input. No more hiss, and gets plenty loud, even without a pre-amp.
I fixed 2 velodyne subs. Yours is a class ab design. the two i fixed were Class D and they are FUN without a hakko..... BTW, why are Silpads 1 time use? I have reused them over and over again and never had any issues. Only time I have an issue is if they tear in half, then I have to replace them. Otherwise I leave them be. When I do replace them, I replace it with Kapton and grease. Also when amplifiers test weaker than they should, the main filters are to blame, they cant hold up to the current draw.
Silpads can be used more than once in non-critical stuff if they are not too dried out or pressed. But I prefer to replace them. The transformer is also another possibility for weak output. I never bothered to measure the voltages to see what the issue was though.
I also was surprised that he says these pads are not reusable. If they are not damaged, they probably last longer than anything else in that amp. I re-used them with no problem so far.
Good video and troubleshooting. I don't understand what is "corrosive glue". Is it that stuff often used to affix caps ..."EPOXY RESIN CIRCUIT BOARD POTTING COMPOUND" ...which turns corrosive with age?
I have a power supply/amp very similar to yours that I obtained. I believe it took a lightning strike. Multiple resister discoloration on the board and fuse looks like an instant burn where you can't see the filament. Like you, I want to use it to increase my skills. Is there a general schematic for these types of boards? I mean I need to relearn how to identify the various segments of the board.
Hey thank you very much for this, I picked one of these up for incredibly reasonable recently and it had the same problems. I'm not sure the electrician that you are but know enough at least to follow along with your level of detail. Now I'm going to hey started with high hopes being able to fix it. So... any way I could ask a question?? I got ahold of a schematic for this and the zener diodes you talk about right by the op-amps are labeled HZ15-3 but I'm having a hard time trying to figure out what to replace them with as they are no available anymore. Can you help?
Like your video, I have a energy xl s12 subwoofer, u am living in the UK ,but the subwoofer is 120 volts, I noticed that the transformer in the subwoofer is housed in a separate compartment away from the amplifier, I was wondering if it would be possible to a change the transformer to 240 volts, not sure if the transformer can be converted also how much volts going to the amp from the secondary side of the transformer.
if i was taking this woofer to a repair shop, at least i would've clean the damn thing.... by the way, excellent videos Maxxarcade! all of them!! thank you
Great video, I'm having a problem with my JBL sub, it's making cracking sounds, I've tried everything, even with no cables pluged in it still does it, Seem like if I turn the radio up real high it goes away, Have you ever seen a problem like this before? And if so could you let me know where I can look it up on the net for the fix, Thanks!!
I had a sub that was working fine for about 5 years then one day it blew the fuse.I'm thinking the same has happened to me as the sub in your video. I want to try and salvage some of the speaker.so my question is can I remove the amp and make it into a passive speaker?
Liked your video but wished you would have shown more of what you did. Talk is fine, just wished you would have shown how you took out the board etc and repaired some of the solider points. Oh well....Still trying to figure out my Velodyne CT120 no sound problem. I no longer hear a click when I flip the switch but I do have lights on
I think this is exactly what's happened to CHT-10R. It looks to pretty much be the same circuit board. On inspection there is that brown glue all over the same diodes. As someone with no electronics experience I'm wondering if I put my mind to it if could still do the repair based off the handy information in this video. The sub has been out of action about half the year and I really don't want to toss it out as it was a $1200 sub at the time and it's a pretty good performer for the last 12 years I've had it. It's just a shame that the electronics have gone. If I took things slow I'm hoping I could do the job.
Update: Thanks to your video I've been able to repair my sub! I can't thank you and this video enough to help me work out what went wrong. The glue oozing all over the diodes and capacitors seems to be the main cause of the issue. Fortunately for me the solders were not cracked, the capacitors seemed to be healthy and that diode was only slightly corroded. Thankfully I haven't needed to seek out new parts and a good cleaning of the board was all that was required. Instead of going to buy thermal tape I opted to use some left over CPU thermal paste to seat it back on the heat sink. Cheers buddy!
Can you please tell me what king of adhesive or glue is good for electronics? I want to keep the parts from moving. I took apart a subwoofer to replace some parts and some of the parts had the same glue as your video. Please let me know the type of glue is that? Or what type I can use to keep the parts together.
Hello did you replace the transistors TIP30B and TIP29C too? If yes I can't find them here in Switzerland. Is there maybe a replacment? If yes do you know with what part number? Thank you.
Hey! I have a CHT-10 and it rattles across a broad spectrum of frequencies and I feel that it is lacking a fair amount of punch. I'm not an expert on these kinds of things. Do you know what may be the cause for something like this? I'm trying to push on it to feel if something is going on with the voice coil and it feels just fine. Thank you
I have a remote version of this model in my workshop (given to me)..Most of the electrolytics are cooked around the voltage regulators so consequently I have replaced them as well as removing the conductive glue...I have also replaced both 15 volt zener diodes and yet despite regulator voltages being somewhere about right, I'm finding the +ve regulator transistor and supply resistor to be running excessively hot!..If I disconnect the pre-amp board, temperatures are good on both +ve and -ve regulaors, leading me to suspect excess current draw on the supply line (both op amps are ok)..This unit is like brand new on the exterior and it's bugging me that it's a relatively simple circuit and the problem is staring me right in the face!! I'll keep plugging away at my Miles Davis, John Coltrane and Michael Brecker music, the EDM is like this sub, giving me a headache!! ;o))
Hello I have a question I have a sound dynamics powered home subwoofer that I found a garage sale, the subwoofer works and all accepted has a constant distortion sound no matter what volume you're at. I remove the amp from the cabinet and hooked it up to another driver and it does the same thing I'm that driver. The sub will for does however perform very well is just very noisy. This sound I'm hearing mimics whatever's being played into it. it is not your normal distortion of over driving something or driving something without enough power. Thanks so much for your help.
Hi! I have the Velodyne Minivee 8 is working but you can hear like a static noise sometimes that noise is louder and then goes away for like 2 mins, what do you think I should check?? the sub is great but that noise is horrible and also affect the quality of the sound.
Max, where are you located? I have a Velodyne HGS12BG sub (the specs say 1250 RMS / 3000) that I picked up as dead from one of my installs. But when I got it to the shop and tried it out, the thing sounded great. But, after a while it started popping, making this loud buzz and finally cutting out. It powers on and no protection circuit light. But no sound either. It sounded great and I would love to get it working again. But shipping alone to Velodyne would cost more then I would spend on a new (lower quality) sub.
I have the dps series from Velodyne with almost the same boards. Mine still works but i'm getting a static noise coming thru the woofer at times. I does it in standby mode too. I called velodyne and they don't service them anymore. The did send me the schematics though. My board is slightly darker by the 2 large capxon compositors and the glue is dark brown. The color is supposed to be a yellowish white. Do I need to re glue these compositors if i replace them?
Do you know what's wrong with my speakers (or woofer unit)? Had these creative 5.1 speakers for a whopping 13 years now, and last night suddenly there was a loud thump noise, the green led on the wired remote volume controller went out, and an ever increasing loud and low frequency humming from the woofer. There is no audio coming through at all, but because the humming increases, I haven't left it on for more than a few seconds. Tried to have a look at the components (although not properly) and didn't notice any obviously swollen capacitors. They've served me well, but I would still like to know if it's fixable. Any ideas please?
Hi, I have a set of Definitive Technology speakers, Specifically BP7002. The subwoofer amps start buzzing after a few years. It is a popular issue with this series. I was wondering if you ever worked on this model or would be willing to make a video repairing the amp. I know this is a common issue and would help a ton of people. Def Tech offers new amplifiers for 150 dollars, but I need at least 2 every few years and its getting outrageous. I think it is probably just failing capacitors but am not sure. I would love to be able to fix these myself.
I have that horrible brown glue all inside my yamaha c45 preamp. Is it a very labor intensive job to get it out. Wondering if it's worth paying to get it serviced? Cheers
Awesome vid, audio and skills! I think I'll just leave one of my broken subs be. Looks like waaaay too much work I'm comfortable at ditching into trying to fix it atm. Also, not sure if it's my things jumping around the table or the stuff from the video :D
Please excuse my ignorance but does the the sub woofer have an active cross over that only plays bass when powered on and plays the highs when powered off?
Awesome Video. Man You know what Your about. Thank You so much. I am picking up a polk sup that went down from my brother. I can troubleshoot a little. Ill Probably send the amp section to polk though. Once again Great Vid and Fantastic Job
hello I have a set of cambridge soundworks t500 towers with 10 inch subwoofers on the sides. One subwoofer started making a wobbling shaking noise especially when there were no deep sounds in the song and even after the song finished playing. The other started making some long beeping screech noise from the amp area of the speaker. I have contacted the manufacturer and the said it was an amp problem and they could fix it if I ship it in but the shipping+repair price is more than what the speaker is worth anymore and I would prefer to try to fix it myself. what could the issue be and how do i fix it? Thank you and any help will be greatly appreciated!!
Hey I got a velodyne chat-10 and it stoped working but the speaker is fine so then I hooked it up to a different system then it still didn't work so I'm guessing it the amp and I can find a replacement so idk what else to do
Heey Maxxarcade, been watching your video to hope to understand more about my problem with my woofer, but im still sitting with this question, perhaps you know? Yesterday night, I decided to turn up the bass volume up to 60% after it sitting for months at like 5% it suddenly made this Loudddd Buzzing noisE and despite me turning down the volume completely the buzzing noise remains so crazy loud! I dont understand what the problem is since I've had this exact subwoofer sitting at 70-80% bass for yearss prior to setting it to 5% Do you maybe have any clue what the problem is? Its a rather small subwoofer too, name of the set = 'US Blaster 3D Subwoofer System'
seems. alright. i need to get a powered sub for my vizio s3820w-c0 soundbar sometime. sure this has Integrated Deep Bass dual deep bass modules and really don't sound bad but could still use it maybe.
hi maxxarcade! i have a question for you. i have a energy ew-100 subwoofer and the problems is, i have a power( red light) but the red light not pass to the green light( when i turn on my amplifier) but unplug, i have a noise provent to the speaker...i dont no for what ??? tanks for your video and please, help me for my subwoofer!!! have a nice day!!!
hi there can yu tell what was problem of volume decreasing in the philips 2.1 home theater of old model of inbuilt fm plzz tell before i used to turn the volume knob lighter it gets more sound but know when now i turning it full it gets less sound plzz reply mee i beg yuu plzz plzz plzz
+Maxxarcade Hello Max,I have a computer set of multimedia speakers made by Boston acoustics made back in 2002 and i am havind a problem with the woofer. The old woofer was blown out so i replaced it with a new one and found two caps that the electrolitic has seeped out so i replaced them.when i tested the system the woofer comes and goes and it does not sound like it should (no power) l cleaned everything with deoxit and everything looks like it is making good contact.Any ideas what the problem might be? I did not change all the capacitors only the ones that where leaking.Exellent video!Cheers
+Maxxarcade Oh, i forgot to mention that to get the woofer to make sound (and not a good sound at that) i have to turn the volume way up.Thank you for any guidance you can give me.Cheers
I love these sort of videos. What sort of camera are you using as the audio pickup was excellent, the bass came thru my computer speakers perfectly. (running a Edifier S330D 2.1 using the optical input on the computer).
hello i have a brand new monoprice 12'' 150 watts powered subwoofer that i brought from amazon that stop working please can you help me with this issues the light comes on but no sound only when i tap on the side of it and it stays on for about 2-5 seconds and goes back off i checked the fuel and it's ok i think i don't know if i such try and get this 1 fix if not to much or such i just buy a new one i paid $150.00 something i had less than a year please help...Thanks!!!
Well, I just picked the same unit up at a rummage. The green LED comes on as yours did, and on mine the Safety relay comes on still. However, where to start the troubleshooting I am not sure. :-( You make it seem so simple. Any help you can provide me would be greatly appreciated. I sure would love to further educate about electronics such as amplifiers mainly, seems to be the main electronic in my life always breaking. LoL I have a few DC car amplifiers I would love to collaborate about too... However, as you said there are just not enough hours in a day. Anyhow, 26 from Indiana, father of 2 beautiful girls, and eager to learn anything you can teach me / aid in my amplifier repairing. Haha long way to go though, this is my first amp fix attempt. But I do have alot of experience with the basic electronic components, soldering, etc... Any help is greatly appreciated. Please and thank you. Have a good one! BTW this video was posted 6 days before my newborns bday tho year! (Personally just thought that was cool) GREAT WORK! You are very good at what you do as I can see. ;-)
The low output wattage isn't because they might be using a 4 or 6 ohm driver is it? You'd be getting closer to the rated output at those rail voltages into a lower impedance driver.
I wondered about that, but I'm pretty sure it's an 8 ohm driver. It measured around 6 ohms DC resistance. Though my shop meter might be a bit out of calibration.
I have an old school velodyne 10” subwoofer..: 1200 watts 12x12 weight about 40 some pounds!!! It not working anymore…I’m looking for a technician to repair
Max, I have a dell optiplex 745 and 755 and for the life of me no matter how much googling no matter how much fiddling i cannot get either one to boot off a USB stick it sees it but wont boot. Its an 8GB cruzer USB stick as well. No matter what i use wether its DBAN or linux mint it wont work. CD works fine as well.
Have you tried a smaller stick such as a 1GB or 2GB? I've had certain ones that didn't boot on a couple different systems. You could also try the Plop boot loader CD. And try making a Memtest86+ USB stick with the included utility to see if that boots. Almost all of my systems have worked with that.
Newer Cruzer sticks report to the computer as a USB HDD, which I find some systems just do not like to boot off. You need to find an older stick that still shows up as a removable drive.
Hi thanks for your tips. I have same problems, but in Slovak republic we don´t have autorized services and any services manual of VELODYNE CHT-8 Subwoofer if you don´t mind, would you send me it ? , thanks
![Look inside $1000 Velodyne 15-inch subwoofer [Disassembly]](http://i.ytimg.com/vi/gj08wiekoSA/mqdefault.jpg)
Thank you for much for posting this. Although this video is 4 years old, it helped me fix a Velodyne DPS-10 in December 2018. Your comment about old brown glue that become conductive was the key I needed. Simply cleaning the brown gunk was all it took to fix the subwoofer I got for free from my neighbor. Please keep up the good work!
YOUR AWESOME !! I have ct veyodyne bought it 35 years ago I love it there amazing. You saved it for me,so I wanted to thank you !! I didn’t blow the diode as yours the same part the plastic door looking thing had a spot came of so one drop solder I was up and running I guess 35 years glue hardens it cracks in that area & breaks that area free & starts shaken THXS MY FRIEND for posting your knowledge 😀 it made my Day
I just wanted to comment on this. I had a CHT-12 that wouldn't output at all. After watching this video I was able to scrape off the old, bad glue from the board and it starting working again! How long will it last, who knows, but for a free fix I am beyond elated! Thank you for making and keeping this video up.
Fascinating to watch your methods of troubleshooting, you (almost) always go straight to the issue, you definitely have a knack with audio electronics !
I wish you had time for online consultations about issues that we sometimes have but I realise that would eat up a LOT of your time and cause you endless difficulties.
Wow, I'm glad I saw this video!
My DPS-10 was fine, but I wanted to check on the condition of the filter caps. They were OK looking, and I would have closed it back up if I hadn't seen this. However I looked down in the "heatsink valley" and found the same carbonized glue! In my case it had started eating through R802, not the diode. I removed all that I could with a long thin screwdriver and blew it out with compressed gas. Then I used the pointy q-tips you can buy at Mouser et al. and some alcohol to remove the rest of the carbon residue.
I think r802, 6.3k, is just a bleeder resistor for the caps so I left it; getting to the board for soldering as seen in this video is a major hassle.
That stuff is not only conductive, it's actually magnetic! It stuck to my magnetic screwdriver.
Sub seems ok after re-powering...
I have the 10" version of this sub and have the exact same problem so was happy to see this video, gives me a good place to start looking on fixing it.
Great plumber ,very reasonable and honest ,definitely my new household plumber, 20 plus tears of experience,this guy knows his stuff! Worth a call-gives free estimates over phone!
Ah, Archie!
Good job on that sub, that circuit board really looked hard to get stuff in/out of, cool thing you got it all working again!
Recap,I fixed it .3 bad lytics tested with esr meter.They were on the eq board that has the volume control and x over adjustments. They were in close proximity of the plus and minus 12v regulators/ no schematic location numbers . lm7912 and lm 7812 ICs. They were 10uf @ 50v ratings on the capacitors.Thought I would share my fix.Symptom was loud humming and motor boating sounds ,volume had no effect.Just full blast noise even if volume was at minimum. Jeff Velodyne hgs 15bg
This was fun to watch and learn from your troubleshooting skills.
I remember when i looked for a ham radio some time ago, and between many 1980-1990 radios made by Kenwood there was a common problem with this brown glue that started conduction into everything! Read many guides to clean everything and was a major thing to do to get the radio working properly!
You noted that the power output was a little low, I wonder if the speaker was in fact 4 ohms, not uncommon with a number of subs I have tested. As you did in fact use a 8 Ohm load this MIGHT account for the lower O/P. Just a thought!
Thanks for posting this video I just picked up a pair of these needing repair you would have thought whoever designed these would have put more thought into the mounting of the board to resist broken solder joints and maybe a better thermal solution good diagnostics and your part! Thank you
Awesome seeing you diagnose the issues like this. I'm still pretty new to this so getting an idea of how to troubleshoot circuits is very helpful. Thanks for posting! :)
You clearly have some skills. Thanks for the well done video. I found it while searching for some insight as to why my 14 year old Velodyne CT 150 is acting up. It powers up fine but is popping and snapping erratically. It seems to be a common problem for the CT series. Anyway, perhaps I'll take it apart to see if there is anything obvious.
Fascinating. Having the same issue with my velodyne where it trips the circuit breaker at 50% volume and I have to cycle it off and on. Wish I had the technical skills to fix this myself!
Holy, your camera picks up the bass really well. :)
That back panel looks identical to an old Kenwood I just picked up. Same screws, heat sink, switches, cord, etc. The Velodyne internal boards are slightly different, slightly more modern looking and both on edge, but basically the same sizes and count and uses similar connectors, the Kenwwood has smaller 3300uF/50v main capacitors and no auxilary caps(the blue ones not mounted on the pcb) and they seem to have leaked.(I get very muddy sound or a pure 60 hz hum, based on how much I wiggle the adjustments)
hell yes, a new vid! I too have a velodyne sub and its been amazing over the past 15 years
I've been seeing that brown glue more and more. I had a nice Philips receiver that started having bizarre issues, including lots of hiss and sound leaking through the different modes (ie, if it was set on CD, you'd faintly hear something connected to the Tape input). Ended up finding that brown glue all over a bunch of logic components, with measurable resistance connecting low voltage logic parts to the +70vDC supply cap.
Really wasn't worth fixing, but the it was a real power house (I was able to load the transformer secondary to over 450 watts without the voltage sagging at all, not sure if the output transistors could take it though).
Luckily, they had designed it in a modular way, so the main amp section was completely self-powered by the +/- 70v Rail, with a simple 4 pin header on the input stage. So I gutted the control electronics, and just hooked up a set of RCA jacks right to the amp input. No more hiss, and gets plenty loud, even without a pre-amp.
I fixed 2 velodyne subs. Yours is a class ab design. the two i fixed were Class D and they are FUN without a hakko..... BTW, why are Silpads 1 time use? I have reused them over and over again and never had any issues. Only time I have an issue is if they tear in half, then I have to replace them. Otherwise I leave them be. When I do replace them, I replace it with Kapton and grease.
Also when amplifiers test weaker than they should, the main filters are to blame, they cant hold up to the current draw.
Silpads can be used more than once in non-critical stuff if they are not too dried out or pressed. But I prefer to replace them.
The transformer is also another possibility for weak output. I never bothered to measure the voltages to see what the issue was though.
Did the rating say RMS? Lately I find some stuff rated in peek or some other non standard way, thought that BS went out with the '70s!
I also was surprised that he says these pads are not reusable. If they are not damaged, they probably last longer than anything else in that amp. I re-used them with no problem so far.
Good video and troubleshooting. I don't understand what is "corrosive glue". Is it that stuff often used to affix caps ..."EPOXY RESIN CIRCUIT BOARD POTTING COMPOUND" ...which turns corrosive with age?
Love to see audio project after a while...
I have a power supply/amp very similar to yours that I obtained. I believe it took a lightning strike. Multiple resister discoloration on the board and fuse looks like an instant burn where you can't see the filament.
Like you, I want to use it to increase my skills. Is there a general schematic for these types of boards? I mean I need to relearn how to identify the various segments of the board.
Hey thank you very much for this, I picked one of these up for incredibly reasonable recently and it had the same problems. I'm not sure the electrician that you are but know enough at least to follow along with your level of detail. Now I'm going to hey started with high hopes being able to fix it. So... any way I could ask a question?? I got ahold of a schematic for this and the zener diodes you talk about right by the op-amps are labeled HZ15-3 but I'm having a hard time trying to figure out what to replace them with as they are no available anymore. Can you help?
Thank you, my CTH work fine now. Just burned glue
Like your video, I have a energy xl s12 subwoofer, u am living in the UK ,but the subwoofer is 120 volts, I noticed that the transformer in the subwoofer is housed in a separate compartment away from the amplifier, I was wondering if it would be possible to a change the transformer to 240 volts, not sure if the transformer can be converted also how much volts going to the amp from the secondary side of the transformer.
I have a sony strdh190 receiver. Not clicking on no display. Any advice. Power light button lights up but dont hear the click? Fuse is good
if i was taking this woofer to a repair shop, at least i would've clean the damn thing.... by the way, excellent videos Maxxarcade! all of them!! thank you
Great video, I'm having a problem with my JBL sub, it's making cracking sounds, I've tried everything, even with no cables pluged in it still does it, Seem like if I turn the radio up real high it goes away, Have you ever seen a problem like this before? And if so could you let me know where I can look it up on the net for the fix, Thanks!!
I had a sub that was working fine for about 5 years then one day it blew the fuse.I'm thinking the same has happened to me as the sub in your video. I want to try and salvage some of the speaker.so my question is can I remove the amp and make it into a passive speaker?
Liked your video but wished you would have shown more of what you did. Talk is fine, just wished you would have shown how you took out the board etc and repaired some of the solider points. Oh well....Still trying to figure out my Velodyne CT120 no sound problem. I no longer hear a click when I flip the switch but I do have lights on
I think this is exactly what's happened to CHT-10R. It looks to pretty much be the same circuit board. On inspection there is that brown glue all over the same diodes. As someone with no electronics experience I'm wondering if I put my mind to it if could still do the repair based off the handy information in this video. The sub has been out of action about half the year and I really don't want to toss it out as it was a $1200 sub at the time and it's a pretty good performer for the last 12 years I've had it. It's just a shame that the electronics have gone. If I took things slow I'm hoping I could do the job.
Update: Thanks to your video I've been able to repair my sub! I can't thank you and this video enough to help me work out what went wrong. The glue oozing all over the diodes and capacitors seems to be the main cause of the issue. Fortunately for me the solders were not cracked, the capacitors seemed to be healthy and that diode was only slightly corroded. Thankfully I haven't needed to seek out new parts and a good cleaning of the board was all that was required. Instead of going to buy thermal tape I opted to use some left over CPU thermal paste to seat it back on the heat sink. Cheers buddy!
Can you please tell me what king of adhesive or glue is good for electronics? I want to keep the parts from moving. I took apart a subwoofer to replace some parts and some of the parts had the same glue as your video. Please let me know the type of glue is that? Or what type I can use to keep the parts together.
Hello did you replace the transistors TIP30B and TIP29C too? If yes I can't find them here in Switzerland. Is there maybe a replacment? If yes do you know with what part number? Thank you.
Great informative video. I've got a Velodyne CT-100 that's humming. Anyone any ideas how to fix it?
Excelent video! Too bad you are not in Mexico... I have a couple of great subs out of order and so far no one can find the problem...
Hey! I have a CHT-10 and it rattles across a broad spectrum of frequencies and I feel that it is lacking a fair amount of punch. I'm not an expert on these kinds of things. Do you know what may be the cause for something like this? I'm trying to push on it to feel if something is going on with the voice coil and it feels just fine. Thank you
I have a remote version of this model in my workshop (given to me)..Most of the electrolytics are cooked around the voltage regulators so consequently I have replaced them as well as removing the conductive glue...I have also replaced both 15 volt zener diodes and yet despite regulator voltages being somewhere about right, I'm finding the +ve regulator transistor and supply resistor to be running excessively hot!..If I disconnect the pre-amp board, temperatures are good on both +ve and -ve regulaors, leading me to suspect excess current draw on the supply line (both op amps are ok)..This unit is like brand new on the exterior and it's bugging me that it's a relatively simple circuit and the problem is staring me right in the face!! I'll keep plugging away at my Miles Davis, John Coltrane and Michael Brecker music, the EDM is like this sub, giving me a headache!! ;o))
Hello I have a question I have a sound dynamics powered home subwoofer that I found a garage sale, the subwoofer works and all accepted has a constant distortion sound no matter what volume you're at. I remove the amp from the cabinet and hooked it up to another driver and it does the same thing I'm that driver. The sub will for does however perform very well is just very noisy. This sound I'm hearing mimics whatever's being played into it. it is not your normal distortion of over driving something or driving something without enough power. Thanks so much for your help.
Hi! I have the Velodyne Minivee 8 is working but you can hear like a static noise sometimes that noise is louder and then goes away for like 2 mins, what do you think I should check?? the sub is great but that noise is horrible and also affect the quality of the sound.
Max, where are you located?
I have a Velodyne HGS12BG sub (the specs say 1250 RMS / 3000) that I picked up as dead from one of my installs. But when I got it to the shop and tried it out, the thing sounded great. But, after a while it started popping, making this loud buzz and finally cutting out.
It powers on and no protection circuit light. But no sound either.
It sounded great and I would love to get it working again. But shipping alone to Velodyne would cost more then I would spend on a new (lower quality) sub.
Wow, that is awesome troubleshooting job. Good video.
I have the dps series from Velodyne with almost the same boards. Mine still works but i'm getting a static noise coming thru the woofer at times. I does it in standby mode too. I called velodyne and they don't service them anymore. The did send me the schematics though. My board is slightly darker by the 2 large capxon compositors and the glue is dark brown. The color is supposed to be a yellowish white. Do I need to re glue these compositors if i replace them?
Do you know what's wrong with my speakers (or woofer unit)? Had these creative 5.1 speakers for a whopping 13 years now, and last night suddenly there was a loud thump noise, the green led on the wired remote volume controller went out, and an ever increasing loud and low frequency humming from the woofer. There is no audio coming through at all, but because the humming increases, I haven't left it on for more than a few seconds. Tried to have a look at the components (although not properly) and didn't notice any obviously swollen capacitors. They've served me well, but I would still like to know if it's fixable. Any ideas please?
How did you connect the subwoofer to the amplifier? My amp has no dedicated sub output and my sub has a single line input?
Hi, I have a set of Definitive Technology speakers, Specifically BP7002. The subwoofer amps start buzzing after a few years. It is a popular issue with this series. I was wondering if you ever worked on this model or would be willing to make a video repairing the amp. I know this is a common issue and would help a ton of people. Def Tech offers new amplifiers for 150 dollars, but I need at least 2 every few years and its getting outrageous. I think it is probably just failing capacitors but am not sure. I would love to be able to fix these myself.
I have that horrible brown glue all inside my yamaha c45 preamp. Is it a very labor intensive job to get it out. Wondering if it's worth paying to get it serviced? Cheers
My Yamaha too. Evil stuff! Planed obsolescence?
Awesome vid, audio and skills! I think I'll just leave one of my broken subs be. Looks like waaaay too much work I'm comfortable at ditching into trying to fix it atm. Also, not sure if it's my things jumping around the table or the stuff from the video :D
Please excuse my ignorance but does the the sub woofer have an active cross over that only plays bass when powered on and plays the highs when powered off?
finally something good in my newsfeed to watch :'D
Zener diode ??? kitane volt ka use hota hai sir plise reply 🙏
Awesome Video. Man You know what Your about. Thank You so much. I am picking up a polk sup that went down from my brother. I can troubleshoot a little. Ill Probably send the amp section to polk though. Once again Great Vid and Fantastic Job
hello I have a set of cambridge soundworks t500 towers with 10 inch subwoofers on the sides. One subwoofer started making a wobbling shaking noise especially when there were no deep sounds in the song and even after the song finished playing. The other started making some long beeping screech noise from the amp area of the speaker. I have contacted the manufacturer and the said it was an amp problem and they could fix it if I ship it in but the shipping+repair price is more than what the speaker is worth anymore and I would prefer to try to fix it myself. what could the issue be and how do i fix it? Thank you and any help will be greatly appreciated!!
Wow, I wish I had your wisdom. Great and entertaining video, I hope you got paid your time for fixing this amp.thanks...
thanks man, this helps alot! im fixing my final s220 sub. didnt get it working yet tho...
Great Video Maxx, you spoke also about troubleshoot HTKS7 subwoofer from HK. Can you share your experience.
Hey I got a velodyne chat-10 and it stoped working but the speaker is fine so then I hooked it up to a different system then it still didn't work so I'm guessing it the amp and I can find a replacement so idk what else to do
Heey Maxxarcade, been watching your video to hope to understand more about my problem with my woofer, but im still sitting with this question, perhaps you know?
Yesterday night, I decided to turn up the bass volume up to 60% after it sitting for months at like 5% it suddenly made this Loudddd Buzzing noisE and despite me turning down the volume completely the buzzing noise remains so crazy loud! I dont understand what the problem is since I've had this exact subwoofer sitting at 70-80% bass for yearss prior to setting it to 5%
Do you maybe have any clue what the problem is?
Its a rather small subwoofer too, name of the set = 'US Blaster 3D Subwoofer System'
seems. alright. i need to get a powered sub for my vizio s3820w-c0 soundbar sometime. sure this has Integrated Deep Bass dual deep bass modules and really don't sound bad but could still use it maybe.
A good illuminated magnifier helps find those dry solder joints.
hi maxxarcade! i have a question for you. i have a energy ew-100 subwoofer and the problems is, i have a power( red light) but the red light not pass to the green light( when i turn on my amplifier) but unplug, i have a noise provent to the speaker...i dont no for what ??? tanks for your video and please, help me for my subwoofer!!! have a nice day!!!
Love the old Marantz preamp
Great video and very helpful. Thanks for upload.
My dad's has the cht-10 and cht-8 and have no issues.
hi there
can yu tell what was problem of volume decreasing in the philips 2.1 home theater of old model of inbuilt fm
plzz tell
before i used to turn the volume knob lighter it gets more sound but know when now i turning it full it gets less sound plzz reply mee i beg yuu plzz plzz plzz
thanks for your detailed videos...might i ask..what is that thing hooked up to the heatsink with 2 white wires ? its at 11:20 mins
Samuel Mugo That is the thermal sensor.
+Maxxarcade Hello Max,I have a computer set of multimedia speakers made by Boston acoustics made back in 2002 and i am havind a problem with the woofer. The old woofer was blown out so i replaced it with a new one and found two caps that the electrolitic has seeped out so i replaced them.when i tested the system the woofer comes and goes and it does not sound like it should (no power) l cleaned everything with deoxit and everything looks like it is making good contact.Any ideas what the problem might be? I did not change all the capacitors only the ones that where leaking.Exellent video!Cheers
+Maxxarcade Oh, i forgot to mention that to get the woofer to make sound (and not a good sound at that) i have to turn the volume way up.Thank you for any guidance you can give me.Cheers
I love these sort of videos.
What sort of camera are you using as the audio pickup was excellent, the bass came thru my computer speakers perfectly.
(running a Edifier S330D 2.1 using the optical input on the computer).
Another job well done!wish i knew electronics
hello i have a brand new monoprice 12'' 150 watts powered subwoofer that i brought from amazon that stop working please can you help me with this issues the light comes on but no sound only when i tap on the side of it and it stays on for about 2-5 seconds and goes back off i checked the fuel and it's ok i think i don't know if i such try and get this 1 fix if not to much or such i just buy a new one i paid $150.00 something i had less than a year please help...Thanks!!!
I have a CHT 12 that turns off where are you located
Well, I just picked the same unit up at a rummage. The green LED comes on as yours did, and on mine the Safety relay comes on still. However, where to start the troubleshooting I am not sure. :-( You make it seem so simple. Any help you can provide me would be greatly appreciated. I sure would love to further educate about electronics such as amplifiers mainly, seems to be the main electronic in my life always breaking. LoL I have a few DC car amplifiers I would love to collaborate about too... However, as you said there are just not enough hours in a day. Anyhow, 26 from Indiana, father of 2 beautiful girls, and eager to learn anything you can teach me / aid in my amplifier repairing. Haha long way to go though, this is my first amp fix attempt. But I do have alot of experience with the basic electronic components, soldering, etc... Any help is greatly appreciated. Please and thank you. Have a good one! BTW this video was posted 6 days before my newborns bday tho year! (Personally just thought that was cool) GREAT WORK! You are very good at what you do as I can see. ;-)
Does anyone know what ohm the amplifier is stable down to? I know they use a 8ohm woofer in it.
I really need your help with my klh 15 in powered sub. Tops and guest ions regarding the amp.
LOVED THIS VIDEO!
Always have plenty of goo done to clean up old glue!
Thanks good job 👍
Where do you get the insulators for the transistors?
Parts Express.
hello Mr. maxxarcade what caps are better for signal path? for filtering? i just want to recap my panasonic rx cw55 receiver.
thank you....
I generally use Panasonic FC for signal coupling if the caps are polarized.
For power supplies I usually go with Nichicon PW or Panasonic FM.
Maxxarcade thank you sir..
The low output wattage isn't because they might be using a 4 or 6 ohm driver is it? You'd be getting closer to the rated output at those rail voltages into a lower impedance driver.
I wondered about that, but I'm pretty sure it's an 8 ohm driver. It measured around 6 ohms DC resistance. Though my shop meter might be a bit out of calibration.
you can connect 8 ohm drivers to ANY amp. ;)
I have an old school velodyne 10” subwoofer..: 1200 watts 12x12 weight about 40 some pounds!!! It not working anymore…I’m looking for a technician to repair
Nice video as per usual man!
Great repair!
man that is dusty but it sounds good for what it is
Is that a sub or an artifact from moria??
hello Maxx where is your shop located I have a sub in need of repair
This is an 8 ohm sub and not a 6 or a 4 ohm? Just curious. I would have thought it would be a lower ohm than 8.
I'm pretty sure it's 8 ohms. The larger ones could have been 4 though. They had 8", 10", 12", and 15" models if I remember right.
Max, I have a dell optiplex 745 and 755 and for the life of me no matter how much googling no matter how much fiddling i cannot get either one to boot off a USB stick it sees it but wont boot. Its an 8GB cruzer USB stick as well. No matter what i use wether its DBAN or linux mint it wont work. CD works fine as well.
Does the USB stick boot on another computer?
Have you tried a smaller stick such as a 1GB or 2GB? I've had certain ones that didn't boot on a couple different systems. You could also try the Plop boot loader CD. And try making a Memtest86+ USB stick with the included utility to see if that boots. Almost all of my systems have worked with that.
Newer Cruzer sticks report to the computer as a USB HDD, which I find some systems just do not like to boot off. You need to find an older stick that still shows up as a removable drive.
WaybackTECH I have not tried it on any other computer but my Dino dell B110 would probably do it at least it did with other USB sticks.
Maxxarcade I have tried a smaller older stick with same ISO burner and what not and still the same issue.
what model pioneer receiver is that on the worktable
SX-850. This will be the third one I've restored.
Thanks 4 the inspiration!
Oops 1 type-o at the end *this year* (accidentally put tho) Thanks again & please reply soon.
I have a DPS-12 that the fuse keeps popping, hopefully I can figure this thing out... (something is shorted)
Where are the fuses located? Are the fuses hard to purchase?
@@dreddrickkingsr.6941 circuit board shorted. Fuses immediately pop
whats the song at 15:15?
edit: okay. max showed it in the end ^^
I really don't want to know the name of the song, but good video!
They are 375W max - 187W RMS.
True power. Valodyne is pretty honest with their products performance.
Class A/B
Help ! Do you have schematics of sub Velodyne D class model DEQ 12 R BV ? Help-me d class brockem !
I've always wondered why they even use that glue on circuit boards.
It was mainly used to mount heavier components such as filter caps, but I find it does more harm than good over time.
Could you give me the link of the music?
Hi thanks for your tips. I have same problems, but in Slovak republic we don´t have autorized services and any services manual of VELODYNE CHT-8 Subwoofer if you don´t mind, would you send me it ? , thanks
I couldn't find a manual either, I had to figure out the circuit myself.
thanks for you but you help me in this my sub is working but my speaker is not i try to use speaker on other sub and it worked