Westinghouse LTV-32W1 PSU blown

[Wizard]

Totem pole MOSFETs blown and 1W fusible resistor crispy in Delta PSU, checked everything for shorts, bad caps or opens. Nothing found. Would a transformer or a controller IC do this in this type of PSU that you come across before?

Transistors is twin STP20NM50FP.

DPS-210EP-2 C REV:01 F

Tested the 5V PWM regulator off the 12V. Working as it should when I juiced it with 12V. I did check the mainboard and 24V LCD panel for shorts. No shorts.

Cheers, Wizard

[Gianni]

Re: Westinghouse LTV-32W1 PSU blown

I don't know this PSU but maybe an over voltage on the line could destroy the power Mosfet.

It is strange that IC PWM is still live if Pmosfet are blown.

Ciao
Gianni

[Shane711]

Re: Westinghouse LTV-32W1 PSU blown

I have a Westing House LTV-32W1 with power supply DPS-210EP-2 C. Turns on but then shuts off after about 10 minutes. I turn it off and it turns back on and stays on for 10 seconds to 10 minutes. It does seem like it might be over heating. I have determined it is the power supply but can't seem to figure out what is wrong because I have 2 PSU and the other one does not turn on. So I checked the mosfets on both boards and they are not shorted. What about the IC ice380565, what is it and can it be the problem? I used a PSU from a different TV and the TV stays on forever but the PSU is not compatible so I get no picture, if it was I would just use that one.

So all my caps, diodes and Transistors seem to be good. Is there a way I can test the ice380565?

[budm]

Re: Westinghouse LTV-32W1 PSU blown

The ICE is for the STANDBY power supply.

[Shane711]

Re: Westinghouse LTV-32W1 PSU blown

So this could be what turns it on and off? I noticed that vibrations seem to cause it to turn off so it may be a bad solder joint. But the second PSU could have a bad IC ice380565. I will check it tomorrow. I fixed one just like it before this one, Westing House 27" had bad transformers on the inverter board.

[budm]

Re: Westinghouse LTV-32W1 PSU blown

You need to show us the full pictures of the power supply, there should be one or two pins for the standby power supply outputs that go to the main board, we need to monitor those to see if the Voltage disappear when the TV acts up or other signals are missing when TV acts up.
You should read Basic LCD TV troubleshooting guide to get better understanding how TV works.

[Shane711]

Re: Westinghouse LTV-32W1 PSU blown

Well, sure enough, it was a broken solder connection on Capacitor C310. In fact both boards had the same broken connection. So now I got a perfect working TV. The picture I included shows the broken solder joint.