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Apex DT502 Digital TV Converter Box blowed up real good. Lets fix it
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- เผยแพร่เมื่อ 6 ส.ค. 2024
- This one blew up awhile ago, but I didn't have any info on the blown part, until I had an old power brick that looked like it might have the right part in it. Lets see if it works.
Cable company here gave those converter boxes out "free" when they switched to 100% digital. About a year later they started billing customers a monthly charge for all of those boxes they'd given out "free".
+10 points for the "Kids In The Hall" reference.
This is not a cable box. It is an off air free tv box to receive the broadcast channels for use with older analog equipment they are great to use with a dvd recorder or VCR to record off the air. Sure every new tv has a digital tuner but say you want to record something off tv. You can't do that today without either a tuner card in the computer or some expensive streamer box that hooks to your antenna. One of these and a dvd recorder and you are good to go. Better still a dvd-ram recorder or dvd-hdd recorder and you are set. These boxes can be set to tune to a channel at specific time then just set the dvd-hdd recorder to record line at at same time and you have an off air recorder. Sure not hd but better than nothing. That's what these boxes are still good for.
@@12voltvids you get a lot more hours/GB your way. Sounds really convenient, too.
@@matambale
Well my internet is unlimited but that's only because I pay more. Costs about 100 a month here for what i get which is only 75 down 20 up. I could get faster speeds for more $
Dave, the hammer repair method will work for that sd card ! Lol !
A first class engineer that walks thoroughly over things.
7:50 Ya, that input filter cap had a little dome on the top.
I miss sctv so much! Farm report was my favorite.
Fortunately, people have uploaded quite a few SCTV skits and even full episodes on TH-cam. It's worth a search.
Good call! I’ve checked it out. Lots of viewing opportunities!
Great video today !
The amount of work you do I am surprised you don't have a solder sucker like a hakko.
The reason i don't it because I did in the past and the cost of replacement tips to keep it running was far higher then buying braid. And i really don't do that much work. That roll of solder braid i have had for probably 10 years. The shop I bought it at has been closed for about 5. That shows how little solder wick i actually use. If some manufacture wants to send me a desolder station to demo and make a video of great, but I am not about to plunk down a couple hundred bucks on something i will never see any payback on.
Good repair, sorry no flames today...
I thought those SMPS chips were a MOSFET, oscillator and feedback all in one 8 pin chip. So a chopper IC with integrated MOSFET for a one chip SMPS solution receiving optocoupler feedback for voltage control. Pinout would be high voltage (commoned pins), ground, feedback, and maybe an enable pin. It seems the pinouts are semi universal, which is good so they can be replaced with non identical model number parts.
They are but as you saw many are interchangeable. That's why I was interested in the drain. They are bridged so seeing the same 78 bridged gave me more confidence it would be compatible.
i have a few of these i bought at goodwill a few yrs ago one of them I bought powers on but has no output to the TV. I'm not sure what's wrong with it but i know the power supply is good because i tried it on another one i had & it works.
You see?
A guy like myself would have found the Mofset and it would have ended there. But experience and talent, delves deeper, and finds the failure cause ?? The Capacitor.
You see? Those fahlt finding techniques need to be remembered.
Heh, i tried to fix 24V antenna power supply and when i replaced bad 400V cap oscillator ic went bang. There were also the other cap 400V witch was really bad. So ic plowed. Obviously there were still high ripple, but the new working cap rised voltage and existing bad cap caused still ripple and it blowed ic. This is only my theory. Nice vid by the way.
Recovering data, please wait...
Hope you put that little stick on heatsink on it again. That will help with not cooking the capacitor again, as it will run cooler as it is able to dissipate the heat better.
Got a satellite one that I use for radio, as I plugged a set of PC speakers that run off USB power into the combined video audio out, and it works well for that, not needing the monitor turned on. As it has a USB memory to record encrypted video for watching later, I used a fake USB hub, that has no actual IC in it, just a fake blob on board, and a random recycled crystal, to look the part, and all the USB data lines are in parallel. So it had the lines cut to let only the first work, and the rest are power outputs. It has a plug in 12V wall wart, which I have plenty of, though I also have repaired a few failed ones, the output capacitors and the small primary side always fails. I keep a kit of parts for this, 220uF, 330 uF, 470 uF 16 and 25V, and 22uF 63V for the primary side. 3 capacitors and they work again.
SD card quality is a guess, as you have no idea if it was a real Sandisk, or a larger part that failed 256G setup, and was resized down to 128G, or was a QC fail that was sold on the grey market, or even a fake one. Buy new one, run a few checks on it, to stress it and fill it up and check real capacity, and then format in camera before use. I did kill a USB memory by running it as OS drive, and with swap and logging at default. Took 3 days before the stick stopped working, unable to write, though a format did get it working again, it had lost capacity, and I did not trust it any more. Still have a few 256M and 512M SD cards around, some still in the packaging, as older cameras do not work with cards over 512M, and some appear to work but just corrupt the card.
The SD should be a real one as it was bought is a real store not online from ?. I have had far better results with lexar and won't be buying any more SanDisk.
@@12voltvids I normally buy Transcend, and only issue I have with them is the actual physical connector wearing out. Lifetime wise using a few in a car recorder, and typically they will do a year or more there before they start to give issues, with the card having had a good number of full writes on the 16 and 32G cards I buy for there. I keep 2 spare ones in the car as well, just in case I need to retain something for later. Transcend because the local computer outlet I deal with normally has them or Kingston in stock.
Hi Dave. You might want to clean the card completely via windows through disk part. Then recreate the file system and reformat it. If you are not knowledgeable on how to use disk part on windows via command line there are video's on you tube on how to preform the steps. Or as you say the SD card might be fubard but it might be an worthy try.
Smashing recovery :-D
i've seen all sorts of dead oddball pwm chips that don't seem to exist on the net.
I really dislike the mosfet incorperated, external on a good heatsink is my favorite.
The TOP brand was well known, they blew up as well lol.
Excercise the sd card in your p.c, i hope the card is the fault.
It's a new camera. I just dropped like 1500 on black Friday back in November so if the camera is bad I'll be getting a new one.
Yes but the typical switcher failure is the switch device going all 3 pins short, blowing out the current sense resistor, and then blowing the controller, so you will still end up replacing 3 parts just to get it running. The integrated devices all often have built in current sensing, using a sample of the source current passed through an internal or external resistor, and often also have a high voltage startup supply, so not start resistor drifting high and open circuit, so it stops working after a power cut. Very rare for the transistor to just short out and not blow all the primary side out.
@@12voltvids Get that sdcard tested as soon as possible.
@@SeanBZA i dont like a hot internal mosfet in the chip with the control circuit.
It's a bad idea.
I have seen more single chip supplys fail than the external mosfet types.
You don't need to tell me the basic functions of a controller, i know already.
I'm not into the odd modes that controllers have to be more efficent.
I know one thing, the buggers still die lol.
@@zx8401ztv going to run it through a full test today. It is blank now so i can do full write.
I don't know that you heard that after 5 years later, the FCC requires all HDTV Stations upgrade from ATSC 1.0 to ATSC 3.0 NextGenTV to have a good reception without having an interference by the flying object, et cetera et cetera, and have customers seek to buy a new converter box or new NextGenTV UHDTV for their own house?
I can see big time push back by broadcasters on this one. You thought the analog push back was bad, forcing them to upgrade the digital, and forcing viewers to upgrade again will cause huge backlash. For starters no TVs have ATSC3 tuners in them yet. If a broadcaster upgrades most will just stop watching off air. Perhaps that is the big plan, if nobody watching no need to broadcast at all. You will have to have cable or streaming and that costs money every month.
@@12voltvids That's beside the point. What it is that, people send a complaint to FCC about the loss of signal by various flying objects, EMF (Electromagnetic Fields), and the storms and winds affect the signal (I'm not talking about people who has a satellite provider). What folks don't realize that whenever they live in their own area that the TV Transmitter stations is far away from their place, they have to seek to get a rooftop antenna and the amplifier to get a good signal to the TVs, and when they are about 5 miles away or less needs an indoor antenna to get a good signal though they can get one rooftop antenna for their TVs. For what I learned that anytime they are getting a so called a quote-end-quote "HD Antenna, UHD Antenna, and Digital Antenna," they are getting the ones that they are not working right and there is no such thing as HD Antenna, UHD Antenna, and Digital Antenna. It's only called Indoor Antenna and Rooftop Antennas. It don't matter what the product has said the way it badge an UHD, 4K, HDTV 1080i or 1080p, and along with the other platform affiliates, the quality that people get a poor design antennas that will not work properly.
The FCC has studied about the loss of signal by test them out about the difference between both ATSC 1.0 and ATSC 3.0 NextGenTV, they learned that the quality of the signal is poorly designed the way it was developed back in approximately in '96 or '99, and the 3.0 ones had a no loss signals at all and still going well. I don't know that is the way it works, but we'll see about that after 5 years.
Now get this! The FCC made a proposal about the low-powered AM Radio Stations who is struggling to have more listeners are required to switch off the analog transmitters and broadcast only in digital including HD AM Radio (Hybrid Digital AM Radio), and to have more listeners listen to the radio stations very clearly without having a low quality audio, statics, crackling and popping, and the interference. It got me to thinking, "what good is that will do if people don't have a HD Radio to listen their favorite radio stations at all for where they have to buy the new HD Radio?" That's in my only thoughts.
However, the full-powered AM Radio and full-powered FM Radio is out there forever and the FCC didn't require all radio stations to switch to digital only broadcasting, because there is no need to take its action to make a switch from Analog to Digital, and the full-powered Analog FM and AM will continue to be broadcasting 24/7. HD Radio stations is not a whole lot of them out there and people are still enjoying listening to their vintage FM and AM radio while enjoying their favorite soundtracks or listening about the news, weather, traffic, and sports. Analog Radios is way stronger and ever.
Meeeeoooowwww??? Where was it??
You know what??
The Meow??😂😂
Bloody cats🤔😂😂
Let me check my box of old remotes. Yours might have stopped here for a breather on its journey around the universe before it returns home.
For small devices such as a DTV converter box, why not just use a linear power supply?
Multiple voltages needed. 5, 12, 33 ect. Much easier and more accurate with smps. Also much more energy efficient.
These days a switching supply is also cheaper than a mains transformer because they are smaller, meaning less material is needed for manufacture.
@@eDoc2020 - it's nothing to do with "smaller". They have a bigger parts count, with much more complexity.
They are cheaper simply because they contain LESS COPPER.
T thought the Peak Forward Voltage in the UK is '240 x 1.41' which is about 340 VAC. Therefore, if my electrical knowledge is correct, the capacitor you changed is NOT rated for the Peak Forward Voltage in the UK. Which is why virtually ALL power caps used in UK electrical equipment are rated for 400 VAC.
its a bit more than a mosfet, it has sense circuitry
Hi Dave, as electrolytic capacitors seem to be very problematic, are there any alternatives available , that would be more reliable?
Nope.
@@12voltvids For the primary side you can use metallised film capacitors, which are available up to 10uF 400V, but which are likely to be bigger than the entire power supply board though. for high values the only reliable thing is wet slug tantalum in a glass frit sealed housing, which is rated for space use amongst others.
Price though from Vishay and Kemet is extreme, especially if you want the higher values and voltages. On the price list as "enquire from your rep", and typically there is going to be a few weeks lead time for them as well, as they are not a commonly stocked item.
I did use some 10uF 25V wet slug capacitors to replace a failed 1000uF 16V low ESR capacitor in a PSU, as I had nothing else around. 3 in parallel to replace it, and the supply rail ripple was very low afterwards, though I also had a 1000Uf 16V after the filter inductor, which was not seeing any ripple, so was not getting hot. Those 3 caps did not even get warm, ESR in the milliohms, and with 5A shared on the 3 just a little above ripple rating. Those 3 capacitors though probably were the same cost as the entire computer they were in, though these were used one from old equipment, from the 1970's.
@@SeanBZA as I said "nothing" to replace electrolytic caps with.
After all it has to fit in the available space and the part can't cost more then the unit is worth.
The only alternatives are better quality electrolytics from a decent manufacturer, like Nichicon, Rubycon, Panasonic, and Nippon Chemicon. At the very least, they'll be more reliable than the cheap Chinese crap that these converter boxes were made with.
@@Watcher3223 Not necessairly. I have seen many Nichicon, Rubycon and Elna caps piss all over the board.
4:17 to 6:15 - Watching you spend TWO MINUTES trying to desolder a DIP-8 on a single-sided PCB was painful!
Get some normal flux (Rosin paste works best but leaves a mess) and smear it onto your desoldering braid, and THEN use it.
You'll be stunned at the difference some flux makes, as it turns it into a vacuum cleaner for solder!
Big deal. I know dipping the wick into flux makes it more efficient but makes a mess. Don't have much in the bottle so why waste it.
don't grasp your solder wick when its hot ;)
Not that hot. I have a high tolerance as i was used to pulling hot tubes out.
I have had many Sandisk memory cards fail on me. I have switched to Samsung memory cards.
I write tested this pos. 6mb write 20 read. Supposed to be 80 read 30 write sustained.
I saw that cap was bulging early on the video!.....thought that one was the cause
I saw that 5 years ago when I first looked at it.
Weird....here we go again. You and l seem to have some sort of weird synchronicity thing going man. Just the other week you posted a vid of you building a 75 ohm FM dipole. The VERY NEXT DAY AFTER l had just constructed an identical one for my Bose New Wave radio. What are the chances of that? I mean just how many people are going to be doung that on any given day?
Now THIS morning you just happen to be working on an APEX brand piece of equipment....
The VERY LAST thing l did before l went to bed last night was repair an APEX brand 3 channel,multi use, music amp, remote switchbox for a customer. It had gone tits-up on him at a gig ladt last Saturday and he needed it before Friday.
I wake up today...and here you are working on an APEX remote box...
Weird man...
Those APEX units runs so hot that you have to remove the top covers when using them. And then when they got so hot they act up. So they are just junk not worth fooling with.
I ended up drilling a couple of holes over the supply area, to keep mine cooler
They all run hot. You should check out a technicilor 8000 4k pvr. They get hot enough to fry an egg on. I have seen them get so hot the plastic deforms when someone does something like stick a DVD case on top of them.
You did make a video on it 5 years ago ( th-cam.com/video/s3XbdjCmEIo/w-d-xo.html ), I had commented the MOSFET part number on that video
Yes I remember. It with a few Memorex boxes that also went boom. It's been sitting in a box for 5 years.
I'm still seeing anti-5G crap. They say it uses untested frequencies. Isn't a million watts over many decades good enough?! That's just one UHF station too. I've noticed these sd cards don't seem to last long anymore. It makes me wonder about the reliability of solid state hard drives. I've seen people taut that solid state hard drives are even more reliable than mechanical ones. All I know is that mechanical hard drives are much more dependable then they were in 2000. Technically, it's best not to have moving parts, so I do see the argument being solid state drives. They do seem to cut a lot of corners with electronics, though.
5 generation cellular used 600mhz, 700mhz, and 3.5 to 4ghz
It also uses the existing 850, 1700, 1900, 2100 and 2500 bands. The real difference between 3g 4g and LTE is channel bonding. LTE for example can use a few frequencies simultaneously. 5g can use all the available bands at once.
>joke I thought that semiconductors used holes to conduct current.>/joke
These things suck. Period. I opened my Chinese off-brand one because it wouldn't turn on anymore and discovered that a cap in the power supply pissed electrolytic onto the board and went open. Threw that piece of crap away lol never again
They have their uses. I use a few for an in house analog cable distribution. My newer tvs have digital tuners but a few old ones i use regularly do not.
im half way through this video and i have to say it why are trying fix this buy a new tv this converter box has some serious milage on it you can tell by the scorch marks around some of the parts on the power supply those things where land fill as soon as they came fresh off of the assembly line
Because these vids are for education.