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- เผยแพร่เมื่อ 24 พ.ย. 2024
- A very cool demonstration of a transformer with a shorted winding, how to locate these issues and one way to repair. If the short is to the core itself or more towards the center of the transformer, we would have to unwind and rewind new copper wire, but luckily on this case the short was only occurring on the last half-wind and we were able to isolate the short with industry standard tessa tape.
I wish all amp repair technicians were as thorough as you are. It's very impressive.
So, why would anyone give this video a thumbs down? This guy took the time to make a video about repairing an amplifier at his own time. He's trying to help people understand that this is how it goes in the amp repair world. I have to assume that the knowledge presented here in this video was too much for the thumb's down people that it literally went over their head and now they are pissed off. I guess I'd like to know why 18 people gave thumbs down....
Impressive work, man. Most techs don't even attempt to repair transformers. By the way, the skinny heat shrink tubing works well for that. Don't get the cheap stuff because it gets hard when you shrink it. The clear colored stuff made by NTE is actually more pliable after you shrink it. Excellent work once again. Cheers!
I'm binge watching your videos and they're such a gold mine of information and troubleshooting techniques. I'm not really working on car amps but more on class d PA stuff and your videos are very helpful anyways. Hope to see you post again soon, but if not thanks for all the knowledge man!!
@@monz7951 thanks man! You are on some pretty old stuff, the more recent has probably more accurate and better information! I appreciate you buddy!
@barevids yes don't worry I'm checking them all!
I normally cut away damaged components then desolder the remaining pins. The risk of damaging the board is greatly reduced.
However in this case repairing the transformer made more sense. Nice job well done.
You have the heart of a teacher.
Nice job.
Your knowledge on electronics is amazing!!!
Fair play Sam. Great video and some great insight on your repairs. Thanks for the recent scv-3000 health check looking forward for the amps return 👍🏻
Finally somebody that knows his stuff very. Helpful I sppreciate thx
This was actually a decently informative video, thanks for your time!
Try a Weller or similar heat gun, makes removing transformers a lot easier & a Heavy duty solder sucker helps. A fibreglass pencil is really useful for cleaning crap off boards.EmeritusE, your spot on: I use 90% acetone for cleaning flux residue from pcb's.
Great job! Great video! Keep them coming. I can't wait for your vids to come up. These help me out more than you know.
great job I thought it was more easy but it's complicated thank you for sharing ur knowledge
Yeah this guy is a Wiz kid for sure. I Love watching these videos :D
fantastic videos,man,i would invest in a small desoldering station because of the many through hole components and huge trace planes,that will speed up work and much cleaner result,keep it up!!
You are a true Master of your trade sir! Keep up the great videos and repairs°°°
Surely armed with this video, the guy could approach the company again and perhaps get a new amp out of them.
If they have any integrity and honour at all they would.
PS. Try occasionally re-stretching the spring in your solder sucker, it improves the extraction.
+Modern Leveller funny you say that, he did actually get a free amp out of this situation! And nice tip on the sucker, will try that!
The whistling just after 26:00 tripped me out lol
Me too
My sound stream reference class a was DOA when I got it. One of the large copper coils had detached from the board. Soldered it back on and voilà.
Your good guy. Thinking of the owner like this.
Thanks I was searching for a video to see a design detail for scratch building. That 27khz is pretty high for what appears to be some pretty large gauge wire on them transformers. The power supply transformers are the section I'm racking my brain trying to learn. I would guess many get built improperly (freq to skin depth to current handling).
Nice Job! Intermittent shorts like that can be a nightmare to find sometimes. When comes to cleaning the board of flux and other nastiness, have you ever tried acetone? It seems to work quite well at dissolving rosin and doesn't leave the residue typical with alcohol strippers.
Thank you so very much for this video. Its straight to the point & so very informative. You are awesome!
Good video. Will be cool to see you start working on home audio stuff too. I would just try to get a decent isolation transformer and variac if you don't have them already. Always better to be safe with mains powered stuff.
great video!
Thanks great video on my welder same thing the transformer got a short cause was hit from drop on the floor 👍🏻🤜🏻🍺
First time viewer, will subscribe! Found you while learning about toroid transformers for my rel subwoofer. Amp board on sub looks really clean. Wondering if toroid transformer can go bad and cause subwoofer to work but REALLY quiet. Good stuff here!
Have you ever thought about building your own Amp ? Check out the $7500 amp offered by D'Amore Engineering, The inside of these amps are a work of art.
Great Videos. Very informative.
Great job
Awesome vid man
Ever thought about preheating the board using hot air before working on the large traces?
Good info. I have a cheap amp that decided to short itself out and blow the fuse. Maybe I can fix it
always such amazing videos 😀
Have you tried using solder braid? I use it daily and it is far easier to use than a solder sucker, and also removes all of the solder. The stuff from RS is good
I havent yet but i plan to get some for sure!
Would make your life 100x easier for sure
Lovings your videos barevids 👍
This is not uncommon when polyurethane coated (self fluxing) copper wire is used as it's not nearly as robust as enamel coated copper wire. There are often interwinding shorts when toroids are wound like this. The manufacturers use this crappy wire because it's fast and easy to tin with a hot soldering iron. Unfortunately enamel coated wire can't be burned off with a soldering iron and has to be cleaned with a blade which is time consuming in manufacture. They really should dispense with a toroid and use a bobbin and a split core but it's too expensive I suppose. I wonder what control IC they use for the PSU? Probably an ancient TL494. These amps are so poorly designed and made that I suspect you'll never be out of work. I've spent my career designing and manufacturing switch mode power supplies so I can tell a lemon when I see it.
Sounds like my problem with my Kicker ZX S1500.1. That protection light “flashing”. Then sometimes amp will power on and play, but soon as I pump up the juice it goes into protect “flashing”.
Hey Sam can I use ca glue to secure some loose windings around the entire top of the inductors? You mentioned you would use some at the solder joints on the board but what about over all the wires themselves is that cool to do ? I see a few loose ones in my amp that will definitely cause problems later so I’m trying to get ahead of the problem before it happens 😊
great video but i got the same problem i find nothing oan the internet on how to rewind the COIL do you got maybe a link the show how to rewind the coil
That board is toasted all to hell. Poor thing has tried to kill itself so much, yet you keep forcing it to live :P
Oh yeah, that looks like the same board as the belva bb5000. And there pretty cheap over here, around $200 to $230. Bassface seems to charge a lot more for there amp.
nice
I have sound stram monoblock 1700.1...dual rai...voltager ac after toroid is normal and balanced,but after reciftier is unbalanced dc voltage...12vlt gab on either side
Is the power supply trying to up the voltage from 12v to sm higher?
Have u gotten a better infared heat sensor gun yet that works correctly? Thanks and if so which one?
do some sub demos like your older videos!
I received an Audiobahn A2150HC that someone stripped the threads on the speaker output set screws for bridging the amplifier. The amplifier works fine so I'd like to be able to repair it. I had thought perhaps that I could use a helicoil. Any thoughts or ideas ?
Good Day. I Must say, your videos are very educational and have helped me a lot in repairs of my personal equipment. So thank you for that as alot of "technicians" in my country are scams and cost me alot of money in the past. They is only one question I'd like to ask. I've recently repaired a 4 channel amplifier I own which had burnt power mosfets. Along one bank, the pcb was burnt and sort of opening in layers. I scrapped all burnt off parts and cleaned with isopropyl alcohol. Then used epoxy resin to make the board solid once again before putting in new mosfets. However after installing new mosfets, I got voltage readings with just B+ and B- connected at the gates of the mosfets on that said burnt side of the pcb (Approximately 1.61V while all of the other 3 banks read 0 V). I wasn't sure if it was defective mosfets from the company. Anyway, I switch out the mosfets of that bank with new ones. Now The amp powers on and works perfectly. After watching this video however, I'm concerned about the pcb being carbonised. My question to you is, how do you know if the pcb has been carbonised and should be cut out like you did in this video? Is it advisable to tear this amp back down and remove those parts of the board between the gate and drain legs of the mosfets in the bank that were burnt?
Note. Due to my engineering background, I have a relatively fair idea of the theory but with practical, I haven't had much practice. Thank you in advance for your time and response.
Sounds like either the drive transistors were leaking or the board is in fact carbonised. If the pull down resistor on the gate path is enough to prevent the leaked voltage through the pcb from exceeding the VT of the mosfet then it will not turn on by accident and can be used like this, although not ideal.
@@barevids Thank a lot. When I had the issue i did indeed change the drive transistors but that didn't solve the problem. I then proceeded to check the mosfets which had a gate to drain short and that's how come I replaced them. After which the amp powered on. I may just tear it down again and remove the carbonised parts. I'll have to look carefully though as the board itself is painted black
Hi recently picked up a quality amplifier it does switch on no sound out of speakers I did have a look inside and there is 6 glass fuses so one of them was blown replaced it and it blew when I switched it back any help will be fantastic
Good job !!!
any ideas about why such trafo often has some kind of loop on pins. I mean they turn wire back to make loop and next as a pin it going into PCB. Why do they need to make this silly loop yet? Rdc and Ls for sure could be higher, so looks like they like lower efficiency and high EMI?
What type of glue do you use for the Transformer core against the board?
Wouldnt it be easier to cut out the faulty transformer and then desolder the legs so it can't dissipate the heat?
Which HP scope is that ? If you had to buy one today which would you get?
You sir is a genius. Thanks for giving newbie a good understanding of this. A question though: if you have the Protect LED light on right after starting powering a car amp. Amp is unconnected to any speaker or input and there is power and ground. What would be the possible causes of the light to go on? I measured all the transistors and found two of the same types and one of the two was 0 across all three leads. would this be the only possibility or it can also be something else? Thanks for all the good info in your videos
Yes that one you found with 0 across all 3 legs is dead. Best to replace all output fets.
@@barevids I know you mentioned this but the parts are not easily to be found. I had to order that one for 10$ (2 part+ 8 shipping) and took the guy like 10 minutes to find an equivalence. Plus I noticed 2 were already changed. I have like 4 different type X 2 for 2 channels. Thank you for your help
@@samerawaragi3041 if you tell me what the originals were I could suggest a suitable cheap replacement
@@barevids 4 transistors MOSPEC bd908 (blown,1OK) bd907 [2 each OK]; MOSPEC f12c20a/c for the rectifier. and there are 2 other ones 3E 8L 1RFZ44N R0040, 3E 8K IRFZ44N R0040 (not sure what are these)
I have a banda 50002 viking series amp that went up in smoke as soon as it was turned on. Do you know if this is a common problem?
Thermal camera will never have visible and IR image aligned on short distances, since those two sensors can be only so close together, that does not change no matter in what price range you will buy. I think your camera works as was intended
The allignment issue is left/right. Not up/down, as would be expected with this layout. And it wasnt only a little bit offset, it was horrifically over to the left. Completely unusable lol even at a distance.
Right, then you have to return it as you said, that is totally different error. Hope to see it in use, might be very useful for some hidden damage or blown IC/transistors... far better than your test with finger, even if it works great
barevids Sounds like something you are more than capable of fixing easily!
Bo Holbo Rasmussen yeaaahh but warranty is easier 😂
Happy New Years quick question my amp is having a problem right when it starts getting warm it shuts itself off it never goes into protect it just shuts itself off what does this mean
I've got a Audiopipe 1800.1. I'd like any recommendations to people you may know in the United States, I could send it to. All I know is there's continuity between positive and negative power terminals. Which indicates a short somewhere. Thanks in advance.
this Schools me-Learn how to find this kind of short circuit , infusion of power supply when testing with Oscilloscope--Sign Waves; maybe im buying one to learn more how to use.
What would cause a rockford fosgate prime r1000-1d amp to go cycle in and out of protect continuously?
What does intermittent shorts in my amp mean?
I need your help I have a four channel amplifier that started making scratching noises then went to protect looking at the inside it looks like three resistors are blown and I have no idea what to do could you help me
yep my amp just took a shit on me today and the gain knob is bad and the amp over heates and goes into protection so its time to put that old school Rockford fosgate amp up and get a new one
hello sir tell me hifonic 2400.1d amplifier main audio output mosfet numbers.
Can't wait for the next vid by the way how's your oscilloscope I just bought one too same as yours
My MTX thunder model number x704 I have change mosfets. When I connect to woofer speaker again mosfets short
i have a alpine 3566 6 channel power amplifier and im getting power the leds come one both green not protect light but im not getting and sound from any of the channel so i checked them with a voltage meter and there getting no power and im not sure what the issue is but id like to fix this as this is a old school amp and it is rear hard to find amp
I love your videos but one thing I wish you could go into more detail is how to test or check the mosfet gate switching transistors, I know they fail sometimes when a mosfet blows and you always insist on changing them but never tell how to check to see if they are still good. thanks
Brandon Shelton I have covered this many times. check drive signal at gate of low side with main output fets out, while driving a 40hz signal into the amp. :)
having problem.what about an amp that doesnt power on,nor show protection mode,but shuts off the 12v power supply when connected to it?
Dead power supply fets
barevids been rolling with you awhile my resistors on the low side are out the mosfet look clean the transformer looks like some dark burnt plastic is on top of the windings, can i send it to you.
Will bad capacitor couse amp to go in production .... my amp stay in protection wont come out
No, shorted output mosfets.
Contact cleaner and a brass brush should remove most of the embedded carbon.
Will you be able to detect the short in the transformer (at least on the secondary windings), by checking the rectifier arrays? I have had a case where one rectifier array seems to be shorted while on the board but looked perfectly okay off the board.
You can't read rectifiers in this way, since you're just reading around the transformer coil. It's extremely rare for the rectifier to die.
I just desoldered the transformer, and the short is gone. all the windings of the transformer have resistance except one has a short to ground. Is there any way to ID it to find a replacement?
U have to unwind it and rewind
I sadly had to give up my old Hifonics TXi 1500D, was running nicely, then after i didnt need it for a day or two, suddenly no sound from the sub. Or rather, intermittent. I wanted to look at it and sort it out but didnt have time. A couple days later, i ended up smelling that nice burnt smell. Took the amp apart and found all 4 transformers shorted and every single damn transistor blown... Not worth fixing it, so i ended up gutting it and am now searching for a good cheap amp in the same price range.
Does seem like the previous owner already had their fair share at damaging the amp, it always smelled a bit funny. Too bad though.
question... is it posible to rewind/rewound those inductors
Yes, do it often 😁
What if my whole amplifier is shorted?
When i measure, i can see that there is fully connection between the "12v" and "gnd", which means that when i turn on the power, it blows all 3 fuses instantly because of the short circuit? What could the problem be?
The power supply mosfets are blown. This will also usually mean that the output mosfets are shorted as well, and the output drivers/buffers, and power supply drivers and gate resistors. Usually when you have this, the amp is badly damaged and will need extensive repair.
Curious about the Tesa tape. Tesa makes a lot of different tapes. Are you using their tape used for bundling automotive wire harnesses or is this their pvc tape used for electrical insulation? Does your tape have a fleece surface? If so that is the wire loom tape which doesn't actually have a rating for electrical insulation resistance according to their data sheets. (that doesn't mean there is no electrical insulation value in your application)
Their electrical insulation tape is a soft pvc tape similar to traditional 3M super 33 black electrical tape and is only rated up to 90 C before it unravels and becomes a gooey mess. (in my experience the adhesive will eventually fail and start unwinding even in summer temperatures of 30c. Tesa's wire harness tapes however are rated from 150 to 300 C which is great for your application.
I'm not saying your use is wrong by any means. At voltages less than 100v their should be no problem as long as you use a couple of layers as insulation since most of those loom tapes are usually somewhat thin.
I'm really enjoying your videos!
Please keep up the good work!
Tony from the Atlanta Georgia area.
Plz for the love of God how can I contact you for repair? I sent some xtant amp to a guy in the USA Shawn king but never got them Back. Now I have a eclipse zx12001 it's works but the out put is very low.
Sorry to say I only offer repairs in the UK buddy!
@@barevids what about some advice on what to look for ? I have a mtx 92001 amp. When I power it up. The two large transformers by the power input are buzzing very loud only with the remote turned on remote turned off there's no buzzing noise it does put out sound but the sound is very staticy and every time the bass hits it washes out as if it's losing power.the amp work perfectly fine before but it's been sitting in the garage for the past couple of months in the cold weather do you think that the capacitors might have went out from the cold here in Chicago?
I don't mind shipping to the UK. I will pay for any fees and surcharges.
What's the model name for that TESA tape/adhesive?
You said it yourself ☺
*VIDEO STARTS AT **6:50*
The amp it a sound stream ta1 3000d
trade mark for not to buy it???
hello how much rise time for irfp064n fets 10 ohm resistor wrong or not
22ohm good for 064n
barevids thanks. you are the best
At ~27:53 you mentioned doing an upcoming repair video on a yamaha mains plate amp. I searched for it in your video list but no luck. I realize this was quite some time ago but if you could help point me in the direction of that vid it'd be appreciated. thanks.
Haven't done it yet lol
@@barevids haha well that certainly explains why I couldn't find it! 🤣
Where is ur shop
Kent, UK
Those can short and arc the MOSFETs blowing parts again
Those worn anodized wiring can also pre fail due to people mounting amplifier on sub box
what is the spelling of the name of tape he is referring to? It sounds like he is saying Tessa tape to me
+mark oshields Tesa.
I have exactly the same scope, the same component tester, the same IR cam, the same Aoyu solder iron, desolder gun & smd heatgun, and the same tweezers! Lol
Holy shit... Brother? 😂
I would have called the "Tech" that had performed the original repair that he needs to send your customer a "New" unit as you have proven that it was caused by a factory defective transformer. Customer gets a new amp and you get full credit! No pay though? Just a thought mate.
The customer was given a brand new amplifier, and this one back fully repaired.
Mr barevids boy I have a 1500 watts audiopipe amplifier bro it burn out my 12inch massive hippo sub boy when I check the output with my multimeter I'm getting 64volts dc bro what can I check boy to solve this problem buddy need your help a.s.a.p please thanks amp turning on normal just getting dc on the output boy
Top comment
Lost monitor
Send that thing back to the manufacture with photo of the problem and have them send you a new one plus the cash this dude is out of pocket. It is and was a covered by warrantee and they need to make it right.
Another well balanced and informative video.. Thank you!
You should check out BigDWiz’s channel. He puts car audio amps through hell using an SMD Amplifier Dyno AD-1 (a dynamometer for testing audio amplifier output power)
Here is his channel: youtube.com - BigDWiz
4
i have 25 years fix amps
My car audio the driver coil and the really is getting hot
Normal