Panasonic TC-L37X1 Dead

[Taterbug]

I am trying to repair a 37" Panasonic TC-L37X1 that is totally dead. No Led. Relays not picking up. I do read 5 Volts on the main Board but that is it. I ordered a new power supply board and replaced it but still the same thing so I then ordered a Main Board thinking this for sure would fix the problem. Still totally dead. I am really puzzled about this one. I unplugged the connectors going to the HV and t-con boards thinking this might be keeping the thing in shut down but that did not help. I looked at some previous threads and went by the flow chart which did not really give alot of info. It just basically said replace power supply board then replace main board... Any suggestions????
Is their some type of test mode I can get into?

[tw2005]

Re: Panasonic TC-L37X1 Dead

I am trying to repair a 37" Panasonic TC-L37X1 that is totally dead. No Led. Relays not picking up. I do read 5 Volts on the main Board but that is it. I ordered a new power supply board and replaced it but still the same thing so I then ordered a Main Board thinking this for sure would fix the problem. Still totally dead. I am really puzzled about this one. I unplugged the connectors going to the HV and t-con boards thinking this might be keeping the thing in shut down but that did not help. I looked at some previous threads and went by the flow chart which did not really give alot of info. It just basically said replace power supply board then replace main board... Any suggestions????
Is their some type of test mode I can get into?

maybe the replacement A board is also faulty? looking at the cct, stdby 3.3v is developed by the A board and the front LED is turned on by the ic4003.

Is there 3.3v at A10 pin 2 in standby?

[tw2005]

Re: Panasonic TC-L37X1 Dead

I think IC5480 produces the 3.3v from the 5v stb

[Taterbug]

Re: Panasonic TC-L37X1 Dead

Not getting 3.3 v there. I am getting 5 volts on pin 3 of A02 that goes to zero when I press the On/off switch. I am also getting 5.5 volts @ A03 pin 23.
I need to know what is keeping it in shutdown mode ??

[tw2005]

Re: Panasonic TC-L37X1 Dead

If there's no 3.3v at that point, unless that V-board is shorted on the 3.3v line then it's dead . I'd be inclined to send the A board back and try another

[Taterbug]

Re: Panasonic TC-L37X1 Dead

Just went back and checked and there is 3.3volts on pin 2 of A10. Power Supply is not turning on and still no LED. I am assuming PS has to be on to read the 12v and 17v coming out of the P board and going into A board at connector AO3. ???? Still puzzled. I wonder if the Backlight Driver Board has a short and is keeping me shut down???

[tw2005]

Re: Panasonic TC-L37X1 Dead

Just went back and checked and there is 3.3volts on pin 2 of A10. Power Supply is not turning on and still no LED. I am assuming PS has to be on to read the 12v and 17v coming out of the P board and going into A board at connector AO3. ???? Still puzzled. I wonder if the Backlight Driver Board has a short and is keeping me shut down???

I still think A board is at fault. If it had stdby led and attempted to turn on you'd at least get an error blink.

See if you can find ic7005 and check if 1.8v stb is coming out of that or look at the manual. I suspect ic4003 needs 3.3v and 1.8v to be ready, it gnds the front led to turn it on so the internal microprocessor ic4003 is not doing it's job and most likely not turned on ready for program execution.

The A board is the correct one for 37"?, not a 32' version? Unsure if that would cause this problem or not but in cct there were labels in the schematic showing differences between 32 and 37 A board .

[Taterbug]

Re: Panasonic TC-L37X1 Dead

Thanks I will check those items.

[Taterbug]

Re: Panasonic TC-L37X1 Dead

Not getting the 1.8volts coming out of the chip. I have contacted seller and am going to return the board for an exchange. That's one of the drawbacks of buying boards from eBay but atleast this seller has a DOA policy and hope fully will let me exchange board for another working one. I put the Old A board back in and there is no 3.3 volts stby at all on it plus when you press the on button it does not go to zero but stays at five volts so it does look like both the original and the replacement A boards are bad.

[Taterbug]

Re: Panasonic TC-L37X1 Dead

One thing I want to make sure I'm doing right before I send back is this. Do I just hold the power on button down on the side of the set and watch for the led to start blinking. I just want to make sure I'm accessing test mode properly.

[tw2005]

Re: Panasonic TC-L37X1 Dead

I don't know anything about holding power buttons down for test mode. All I know is there's a self test and service mode. For both the TV needs to turn on and that's not happening. I don't deal with the LCDs normally but I have a baby 2010 Panasonic LCD and holding the power button does nothing as far as inducing a special mode or error blinks

[Taterbug]

Re: Panasonic TC-L37X1 Dead

Ebay just refunded my money and I returned the defective A board. They did not have a replacement and I dont wont to spend $100.00 on this on so I am gonna tell the owner no go on this one. Sometimes you the the bear and sometimes the bear gets you. Thanks for the help.

[Taterbug]

Re: Panasonic TC-L37X1 Dead

I found another A board on ebay for a decent price and ordered it. That is what the problem was. It's got a great picture... Just wish the boards we get off ebay were always 100% reliable. At least I got my money back for the bad board and everything is now working.

[vinceroger69]

Re: Panasonic TC-L37X1 Dead

Thanks for the update glad the tvs working now.