Switching power supply repair

[lynx]

Hi,

Junk it, buy a new one

I rarely tell anyone this, but this is one of those exceptions. If you could not figure out what was happening before, you'll never figure it out now without getting extremely lucky.

If you seriously still want to try to fix this you'll probably have to get a schematic. Maybe tracing out the PC board would help, but without knowing the IC part number it's very difficult.

hi
i respect your experience and your excellent reputation you got here at the forums...but this is not
an advice that you gave...

we don't throw to the garbage or salvage a device before we make sure it's not repairable or time and cost worthy to
do so... worse case scenario maybe you could advice me to use a computer power supply to power up this thing.

despite that...what i'll try to do next is to buy the IC that got burned...i think i'll order the ICE2A265 or ICE2B265
any opinions?

 

[MrAl]

Hi again,

Well i see now that you are willing to go the distance, and that's very admirable.

It sounds like what you are telling me is that it is ONLY the power supply, so with a new power supply it will work again. I had thought that more than that blew up this time for some reason i.e. it sounded worse than it is.

Are the only outputs +5 and +12 volts? We could find a new power supply to do it probably not too expensive if it only has to put out 5 amps at 12 volts.

 

[ronv]

Have a look here. If it still didn't work at least you might have some useful parts left over.

https://www.allelectronics.com/make-a-store/category/480/power-supplies/1.html

 

[lynx]

Hi again,

Well i see now that you are willing to go the distance, and that's very admirable.

It sounds like what you are telling me is that it is ONLY the power supply, so with a new power supply it will work again. I had thought that more than that blew up this time for some reason i.e. it sounded worse than it is.

Are the only outputs +5 and +12 volts? We could find a new power supply to do it probably not too expensive if it only has to put out 5 amps at 12 volts.

no the power supply outputs various voltages, 3.3v, 5v, 12v also negative ones and also i think 18v or 24v for the display.

ronv thanks but none of these are needed

 

[MrAl]

Hi,

Ok well good luck finding that type of power supply
Also, good luck with the new chips.

If the 24v supply does not need too much current then you might try a boost circuit or just buy a cheap boost power supply board already built, maybe adjustable.

 

[lynx]

Hi,

Ok well good luck finding that type of power supply
Also, good luck with the new chips.

If the 24v supply does not need too much current then you might try a boost circuit or just buy a cheap boost power supply board already built, maybe adjustable.

ty... i think the boost converter would be a good idea because the display it's a vfd, but that's something that i look
in case i don't manage to repair the power supply.

 

[KeepItSimpleStupid]

ICE1Q01 perhaps: https://www.google.com/url?sa=t&rct=j&q=&esrc=s&source=web&cd=8&cad=rja&uact=8&ved=0CFcQFjAH&url=https://arizanotlari.com/Semalar/Tv/lcd/telefunken/power/04ta069b-sema.pdf&ei=kwJKU4r3CM6W0gHx3oCgBQ&usg=AFQjCNEY4pVCvCxlfi2Bhmycu_8InqnH7g&sig2=9AxuN5EHN2DlhoZogS1YDg&bvm=bv.64542518,d.dmQ

I guess there is a bunch to choose from: **broken link removed**

and datasheets:
**broken link removed**

 

[MrAl]

ty... i think the boost converter would be a good idea because the display it's a vfd, but that's something that i look
in case i don't manage to repair the power supply.

Hi,

Yes, and i hope that if you do repair the old power supply that it does not blow up again because we didnt find the reason it blew up in the first place.

 

[lynx]

ICE1Q01 perhaps: https://www.google.com/url?sa=t&rct=j&q=&esrc=s&source=web&cd=8&cad=rja&uact=8&ved=0CFcQFjAH&url=https://arizanotlari.com/Semalar/Tv/lcd/telefunken/power/04ta069b-sema.pdf&ei=kwJKU4r3CM6W0gHx3oCgBQ&usg=AFQjCNEY4pVCvCxlfi2Bhmycu_8InqnH7g&sig2=9AxuN5EHN2DlhoZogS1YDg&bvm=bv.64542518,d.dmQ

are you sure about that? because i was thinking to buy the ice2a365, did you checked if the one you propose is compatible with my
power supply? because i haven't yet..

 

[KeepItSimpleStupid]

No, haven't. The selection guide seems to SUGGEST that the IC's are very similar and discontinued easily. I noticed that ST had a 7 pin IC and not 8 pin. I could not tell if your board was 7 pin DIP or 8 Pin DIP.

Wattage is one thing to use and comparing to the "reference design" is another.

I get the FEELING that most of the IC's in the series are improvements and MAY substitute for one another.

 

[MrAl]

Hi,

I forgot to mention that i had an old TV once that i liked and did not want to throw it out, but the front end power supply blew out. Lucky it was just a rectifier diode, but later the high voltage flyback transistor blew out. I found out the transistor had a very high voltage rating and the highest voltage transistors i had were something like 450v, so i used a very unusual connection of four transistor CE junctions in series with special base drive arrangement to find out if it would work again. Sure enough, it did work up to a certain voltage (i did not want to go too high with that arrangement) but then i chickened out because a replacement transistor would have cost something like 25 dollars, and i did not want to spend that much if i did not know why it blew out in the first place. I suspected it was because the heat sink became a little loose, but who knows. If i bought another one and it blew out a week later, it would be a total waste. So i put the money toward a new TV that came with better features.
I am just mentioning this because if you do repair it and did not replace a single part that caused the failure then it could blow again, so it depends on the cost of the repair if it is worth trying or not. If it does blow out again and the parts are not that expensive, then maybe you can try a second time after replacing more parts.

When my older PC power supply blew out i checked ALL the capacitors just to make sure. Some of them were bad so i replaced those plus a few more with quality parts. It's hard to tell if a smaller cap is bad sometimes, and that alone could cause a failure.

A real long time ago i used to fix home entertainment stuff for people as part of my living. Then i used to replace whatever i found bad, and if it worked then i called the customer and they came and picked it up. If they had another problem because something else was wrong then i would fix it for free the second time after replacing more parts that were either bad or could have been bad but where hard to test in circuit.

 

[KeepItSimpleStupid]

real long time ago i used to fix home entertainment stuff for people as part of my living. Then i used to replace whatever i found bad, and if it worked then i called the customer and they came and picked it up. If they had another problem because something else was wrong then i would fix it for free the second time after replacing more parts that were either bad or could have been bad but where hard to test in circuit.

I helped a consumer repair business out for a while by servicing audio amplifiers at home. I only did the high power and harder stuff. They repaired an amp a couple of times and finally gave it to me. It was a fancy surround sound receiver which blew one of the IC amps. The power supply rails could exceed the absolute max rating of the IC. So, that was the root cause and it was fixed for good. But, yea, freebee on their part.

 

[lynx]

Hi,

I forgot to mention that i had an old TV once that i liked and did not want to throw it out, but the front end power supply blew out. Lucky it was just a rectifier diode, but later the high voltage flyback transistor blew out. I found out the transistor had a very high voltage rating and the highest voltage transistors i had were something like 450v, so i used a very unusual connection of four transistor CE junctions in series with special base drive arrangement to find out if it would work again. Sure enough, it did work up to a certain voltage (i did not want to go too high with that arrangement) but then i chickened out because a replacement transistor would have cost something like 25 dollars, and i did not want to spend that much if i did not know why it blew out in the first place. I suspected it was because the heat sink became a little loose, but who knows. If i bought another one and it blew out a week later, it would be a total waste. So i put the money toward a new TV that came with better features.
I am just mentioning this because if you do repair it and did not replace a single part that caused the failure then it could blow again, so it depends on the cost of the repair if it is worth trying or not. If it does blow out again and the parts are not that expensive, then maybe you can try a second time after replacing more parts.

When my older PC power supply blew out i checked ALL the capacitors just to make sure. Some of them were bad so i replaced those plus a few more with quality parts. It's hard to tell if a smaller cap is bad sometimes, and that alone could cause a failure.

A real long time ago i used to fix home entertainment stuff for people as part of my living. Then i used to replace whatever i found bad, and if it worked then i called the customer and they came and picked it up. If they had another problem because something else was wrong then i would fix it for free the second time after replacing more parts that were either bad or could have been bad but where hard to test in circuit.

yeah i understand what you mean, and i agree, but the power supply i'm dealing with it's just childish, there's no way an experienced person
not to understand how to repair it, even me, that i don't have any serious knowledge i can understand enough of it, for example...
all the "high voltage" side it is built around the SMPS IC which is probably the ICE2A265 (unfortunately has nothing to do with
what KeepItSimpleStupid proposed) the pinout it is exactly as the ICE2A265 and even if it is not the exact IC the board uses, then
it's another less wattage or more wattage.

if you check the board all the left side it's just filters and a bridge rectifier out of 4 simple diodes, and the standard infineon circuitry for the ICE2xxxx series ICs.
the right side is more mystery to me and i only understand the circuitry around the LM317T which is correctly placed
from the factory because while i was thinking it again and after a talk with a guy, there's NO way the DVD motor to require 12V/5A to spin!!! probably 5 amps are needed only as a peak current.

so to summarize...the initial problem i don't know the cause, could be broken joints that i haven't noticed maybe?
i found the lm317t that i had desoldered and i tried it somewhere else and it works just fine! even though while it was
on the power supply it was getting extremely hot (120c) and it couldn't start the dvd motor.

why the lm317t was getting hot while i was connecting the dvd connector? maybe the input-output voltage difference+current
was too high?? (too much dissipation on the TO-220 package)? if that was the case..then what could cause the
transformer pin to output higher voltage to the lm317? maybe the SMPS IC it's the cause of the issues and was already
faulty and that's why it blew after awhile? the board has a deep brown colour around the IC long before it blows off... and that probably means it was getting already too hot...

this device deserves to be fixed and i will be very sorry if i don't, could you please try to boost my effort? thank you.

 

[KeepItSimpleStupid]

How about a make and model number?

 

[lynx]

How about a make and model number?

hyundai hdr-5001

it is this one https://mastercare.gr/images/products/13212.jpg

but i couldn't find any information on the internet, probably it is made by another company
and it is imported to my country by that name.

despite that, it was working perfectly since 2008 and still works if the power supply gets fixed
costed about 120 euros (160 usd) and there's no need for extra spending since it's not total garbage.

 

[MrAl]

Hi,

Oh ok well it sounds like you really like this unit for some reason.

Is there any chance you can make a drawing of the circuit board connections (schematic) yourself by tracing out the circuit board?
I've done this a few times in the past when there was no schematic available. It's not easy but if you take good photographs of both sides of the board (maybe a couple each) you can do it, and this circuit does not sound super super complicated. So maybe we can get this thing up and running again.

If you cant make a drawing (and i really really hope you can) then maybe at least post good pics of the front side and back side, so we can see the connections too. This might not be possible though because although the boards are two dimensional (more or less) the components are three dims and get in the way sometimes, so you may have to draw up the schematic yourself.
I can tell you that if you draw a good schematic and label where the inputs and outputs are and what voltages to expect there (inputs and outputs should be easy to tell) we can almost definitely fix this thing, unless maybe a transformer is bad and is too hard to identify or figure out what a replacement could be.

One of the other things i would also look for is bad snubber caps, asuming they do use snubbers, although they might not use them.

 

[lynx]

seems that the power supply it is known..

mine is vestel 12pw3050-2

 

[lynx]

the schematic could be similar to this

 

[KeepItSimpleStupid]

Image isn't really readable.

 

[lynx]

Image isn't really readable.

this is the schematic...right now i'm checking it and the high voltage side it's exactly the same with mine, could you please download from here...because i've reached my download limit for today and i can't get pdf, i could only get the png photo.

https://elektrotanya.com/vestel_12pw15-6_dvd_power_supply.pdf/download.html

also..the SMPS IC has been replaced with the ICE2A265 but the power supply does not start.. (i can't hear the high pitch noise from the transformer), i took some measurements and the voltages don't seem right.