SAMSUNG 933HD exploded.

[Nekax]

Hi, I have a problem with the power supply of a Samsung LCD TV 933HD.

There was a short circuit in the mosfet transistor and the integrated circuit one exploded in the bottom of the plate and i can not find the schema of the TV.

I need the picture or reference of the integrated circuit, and the other components is have located already.

Here you have some photos of the source and marked with a red circle, the integrated circuit that exploded.

I hope you can help me, thank you very much.

[retiredcaps]

Re: SAMSUNG 933HD exploded.

Service manual at

http://elektrotanya.com/samsung_933h.../download.html

[Scenic]

Re: SAMSUNG 933HD exploded.

the green resistor on the top (R114) seems to be missing a chunk.. just btw

[Nekax]

Re: SAMSUNG 933HD exploded.

Service manual at

http://elektrotanya.com/samsung_933h.../download.html

retiredcaps, Thanks for the link but I can not download the file.

Scenic, I have located already all failed components , I only need the integrated circuit reference which exploded, and thanks for the comment, It's always good to look all. jeje.

[Scenic]

Re: SAMSUNG 933HD exploded.

i'm downloading it right now. pain in the ass to get to the download link..

will be reuploading it somewhere else..

edit: seems like the edit time limit was raised..(?)

anyways.. here's the link

http://www.4shared.com/file/m3LcO83c...EKFEN__Se.html

[Krankshaft]

Re: SAMSUNG 933HD exploded.

A power surge could have taken out that PWM IC. The chunk out of the resistor supports the theory.

The ICs startup circuitry is connected directly to the unregulated DC. This is usually where the surges come through which can fry it. The unregulated DC is used to kick start the PWM so it can start driving the switching transformer at which point it is able to sustain itself with it's own regulated output.

It's this type of closed loop circuitry that makes switchers a bit more difficult to troubleshoot.

I'd replace that small cap near the bad resistor too it's also probably part of the startup circuit. As far as design goes this power / inverter board is pretty simple and shouldn't be that hard to get running again.

[mbates14]

Re: SAMSUNG 933HD exploded.

youll need the resistor, MOSFET, and IC at the very least.