[SharpSteve]

My LC-C3234U got fried by lightning about a month ago. I bought a new power supply board and I think it is DOA. Can someone with one of these that works open it up and give me some voltage readings? I want to make sure that the new board really is dead before I try again. The picture shows the voltages I am looking for. These are on the upper left hand side of the power board. The back has 10 screws that hold it on (look for the small one in the middle of the input connector area.) The power board it totally exposed once you remove the back. Just pop off the connector and use your handy multimeter. I don't think I have to say "be careful not to short pins together." I don't want anyone else's to go dead like mine. Thanks!

 

[hammerdwn]



Quote:
Originally Posted by SharpSteve /forum/post/16898311


...Just pop off the connector and use your handy multimeter. I don't think I have to say "be careful not to short pins together."

Do not pop off the connector to take voltage readings because the Tv may sense it's disconnected and go into shutdown mode. Get a meter probe that can take readings with the connector still on.


What are the symptoms of the Tv?

Some of the connectors are labeled with voltages, are you getting correct readings on those?

 

[SharpSteve]

I see the logic in NOT disconnecting the connectors. I took the BU5V (backup 5vdc?) and it is 5 vdc. After some more thought last night I think that the 5vdc is used as standby power. When you hit the power switch then the 13v should come on. BUT, mine doesn't come on. When I hook up the new power supply board and push the power switch on top of the TV, nothing. No satisfying click of relays passing electrons to LCD screen. Nothing. Loads of searching online netted me a Sharp service manual for a 37" LCD. Many of the schematics look similar to what mine is, and the mainboard part number is a direct replacement for mine. Is it worth trying to sift through it to find the chips and test them individually? I have some experience troubleshooting, but I know sometimes its just chasing ghosts. I am worried that the "turn on" circuit on the mainboard may be bad. If it is, the mainboard is another $210, combined fix price of $360, still cheaper than a new TV as good as this one. Anyway, anyone willing to take some voltages would be appreciated. Maybe even a close size will have the same connector setup. If you don't have the right test leads a pin or paperclip taped to the tip will get you a sharp point for reaching into connectors. Thanks again.

 

[hammerdwn]



Quote:
Originally Posted by SharpSteve /forum/post/16901542


...When you hit the power switch then the 13v should come on. BUT, mine doesn't come on... I am worried that the "turn on" circuit on the mainboard may be bad...

Ya, seems like the next logical possibility. Wouldn't even bother component level troubleshooting on the Main.