Polaroid FLM-3234B Power Supply

[tom66]

Re: Polaroid FLM-3234B Power Supply

I thought it just blew up, would usually be pointing to a fault, also if this PSU has PFC, that cap should hit 390V.

[kevinm34232]

Re: Polaroid FLM-3234B Power Supply

Im not sure if it has PFC or not, this is a break thru just to get standby power. What can I look at now?

[kevinm34232]

Re: Polaroid FLM-3234B Power Supply

The 16pin IC is an MC0628R do you think with all the problems in the primary side that could have been damaged, does that control the PFC if applicable?

[tom66]

Re: Polaroid FLM-3234B Power Supply

Have you posted a picture yet?

[kevinm34232]

Re: Polaroid FLM-3234B Power Supply

Post #3 let me know if you need to see anything else

[tom66]

Re: Polaroid FLM-3234B Power Supply

Very good, didn't notice! Can't find anything on that IC? But the supply definitely looks to use PFC to me - there's a PFC choke on the board. It is possible IC2 is damaged and keeping the MOSFET permanently on.

[kevinm34232]

Re: Polaroid FLM-3234B Power Supply

Does the IC control the PFC circuit then, not too familiar with how the PFC works? I suppose I can try replacing that IC for one last go at it..

Would it make sense that we'd not get both 12 and 24v if that was the issue?

[tom66]

Re: Polaroid FLM-3234B Power Supply

Not sure, can't find anything on it...

[kevinm34232]

Re: Polaroid FLM-3234B Power Supply

Well I just ordered one for $8 we'll see what happens, appreciate all the help with this one was a great learning experience regardless of what happens!

[kevinm34232]

Re: Polaroid FLM-3234B Power Supply

Tom I woke up this morning still thinking about this damn tv! The last part I removed looking for that short was an IC on the bottom of the board. Then I was freakin out because there was no markings on this chip designating pin 1. Anyway I wound up getting it back in the right way, but turns out I had a small amount of solder touching pins 1 and 2. I fixed that an voila TV finally came on! So I looked up that small chip and interestingly it is part of the PFC control we were talking about of all things.

https://cdn.badcaps-static.com/pdfs/...3407e8de8a.pdf

So now the TV is working, (with a buzzing now coming from one of the inverter boards) LOL, never ends! Thanks!

[tom66]

Re: Polaroid FLM-3234B Power Supply

Glad to hear it was sorted, so was that the original fault? I am lost.

[kevinm34232]

Re: Polaroid FLM-3234B Power Supply

No the original fault was the blown transistors Q8 and Q9, Z4, and the main cap. That was something I did after the fact trying to find that short.

I watching the TV now but I get this buzzing from the right side inverter board, do you think that is a seperate issue or still possibly a PS issue? Im getting the 23.9v and 11.6v from the PS board now.

[kevinm34232]

Re: Polaroid FLM-3234B Power Supply

It sounds like an old movie projector, and the pic flashes rapidly also..

[tom66]

Re: Polaroid FLM-3234B Power Supply

What's the voltage across the big cap.

[kevinm34232]

Re: Polaroid FLM-3234B Power Supply

It is around 305V

[tom66]

Re: Polaroid FLM-3234B Power Supply

Probably needs to be closer to 390V (esp. if TV is rated 100~240V or so)... check soldering around big cap, and resistors from it to PFC IC.

[kevinm34232]

Re: Polaroid FLM-3234B Power Supply

resoldered the main cap and didn't find anything else. BTW this is the cap I ordered hope it's the right one:

http://www.digikey.com/scripts/DkSea...673-ND&cur=USD

Because it is a relatively thin, long cap to fit in it's spot I ordered by dimensions. The legs weren't long enough to bend so I had to solder some wire jumpers to it to get it to lay down. Now I have it soldered directly just to see but no changes.

Also if the voltage on the cap is too low would I still get the 24v and 12v?