Soniq E48W13A-AU Bad P/Supply

[saddle_au]

I have a Soniq 48 inch LCD TV Model E48W13A-Au which is suffering from severe heat issues on the P/S in the area of the led drive. The TV tries to wake up from standby, but doesn't get past switching off the red standby led.

Most of the output caps have popped due to the temp coming from two what I think are diodes located under the board (guess which spot!!).

1) Has anyone seen or dealt with this before?

2) Does anyone have a Megmeet MP48-QG schematic?

3) I don't know what the parts underneath actually are, I think diodes, but I cannot find references to D458 or CA3316 anywhere.

4) I might suspect the leds in the panel caused this grief, but I would like to give the P/S a go first before tearing the panel open.

Any and all help appreciated.

[diif]

Re: Soniq E48W13A-AU Bad P/Supply

It's a mosfet.

[budm]

Re: Soniq E48W13A-AU Bad P/Supply

Please attach good clear straight shots pictures of the whole bottom side of that power supply board.

[saddle_au]

Re: Soniq E48W13A-AU Bad P/Supply

Hope these are clear enough, there's a 2000 dot limit on the file size.

[dick_barton]

Re: Soniq E48W13A-AU Bad P/Supply

I wonder if they overheated due to the capacitors high ripple current due to the capacitors failing over time.

[budm]

Re: Soniq E48W13A-AU Bad P/Supply

That is boost converter section, if those filter caps for feeding the B+ to the boost converter were slowly loosing capacitance, then the circuit will not be running at the design frequency due to modulation between power supply frequency and the boost converter frequency so the circuit will draw more current. If some of the LED shorted out (there are two LED strings), I will then expect the PWM controlled MOSFET's on the heat sink will get hot.
I also hope that the boost conductor core is not damaged by the heat.
At this point did not indicate if those two MOSFET's for the boost converter are OK or not, if they are not shorted out and tested OK then he should replace the caps and see what will happen.

[Vandalyst]

Re: Soniq E48W13A-AU Bad P/Supply

I just came across this post and I noticed my board has discolouration at the exact same location ...
Was this problem fixed by replacing Caps?

[nomoresonys]

Re: Soniq E48W13A-AU Bad P/Supply

are the tops of your caps bulging at all, hard to tell from picture, if they are replacing all of them is where to start and might be all that's wrong.

[Vandalyst]

Re: Soniq E48W13A-AU Bad P/Supply

I have replaced all the caps but the tv won't power up ..
it still is stuck at standby

[nomoresonys]

Re: Soniq E48W13A-AU Bad P/Supply

check those diodes right there in that burnt looking area, check those 2 components on the heatsink there, how does that area look on the underside of the board?