Panasonic TX-37LX85P blink 3 times

[vinceroger69]

Re: Panasonic TX-37LX85P blink 3 times

a replacement board is quite cheap if the white bar code sticker number matches
http://www.ebay.co.uk/itm/Pansonic-L...120924775#shId
depends if you have to pay duty on it.

[tom66]

Re: Panasonic TX-37LX85P blink 3 times

Great! That's not too bad. Perhaps it would be prudent to remove the module first and do some tests on it. Testing from VIN (pin 6) to SW-NODE2 (pin 12) should reveal a short.

Replacing the board is also a good option, if you want to do that.

[rtstorm]

Re: Panasonic TX-37LX85P blink 3 times

Ok first i will remove the component and test it. Can i use something to test, like 9V battery. I don't wana buy the power supply board if the other (a-board) is bad

[tom66]

Re: Panasonic TX-37LX85P blink 3 times

I don't think a 9V battery would have enough grunt unfortunately, but you could try using 6x1.5V alkaline or NiMH, or using a lab power supply. Don't use a wall transformer as they're usually unregulated (15V no load for example.)

[rtstorm]

Re: Panasonic TX-37LX85P blink 3 times

i try it with 6x1.5V battery but nothing happend. i am giving up

[tom66]

Re: Panasonic TX-37LX85P blink 3 times

When you can get PSU for under £30 or part for just £10?
It is most likely PSU at fault.
I would not give up, it is a 37" Panasonic LCD TV, which costs a lot here (I don't know about prices in Croatia.)

[rtstorm]

Re: Panasonic TX-37LX85P blink 3 times

yea it cost here a lot, but i am crazy. I tested the DC/DC device and it has 0.5 ohm between #6 and #12. Ok i will order PSU from ebay, and hope that will then get picture.

[rtstorm]

Re: Panasonic TX-37LX85P blink 3 times

The new power supply board came, i connected it and the same 3 blink.
I check voltages and i got 5V on #1 #2 and #5, should i try to force it with wire and resistor?

[tom66]

Re: Panasonic TX-37LX85P blink 3 times

Can you test the DC-DC on the new board and see if it still has 0.5 ohm short?
It is possible the A Board has been damaged by this over-voltage though I'd expect a different blink code (or no function at all) if that were the case.

[rtstorm]

Re: Panasonic TX-37LX85P blink 3 times

I tested it and it's a 275 kOhm

[tom66]

Re: Panasonic TX-37LX85P blink 3 times

That's good then... How is SUB9V now?

[rtstorm]

Re: Panasonic TX-37LX85P blink 3 times

it is 0V, should i try force it with wire and resistor?

[rtstorm]

Re: Panasonic TX-37LX85P blink 3 times

I connected #1 and #5 & #6 with wire, and #1 with #15 over resistor. I got on #11 & #12 9V, and on #20 & #21 18V. I tested it on TV, but i didn't connect it to the main board.

[tom66]

Re: Panasonic TX-37LX85P blink 3 times

I think we should consider disabling the 3 blinks detection to see what the TV does. Removing the appropriate transistor on the A Board should do it.

[rtstorm]

Re: Panasonic TX-37LX85P blink 3 times

Ok, i think this 3 blink is some kind of firewall.

[tom66]

Re: Panasonic TX-37LX85P blink 3 times

What do you mean by firewall?

[rtstorm]

Re: Panasonic TX-37LX85P blink 3 times

i mean that it is preventing power, like you say. how can i find that transistor

[tom66]

Re: Panasonic TX-37LX85P blink 3 times

Try Q5615. Just lift two legs to isolate it from circuit. If that does not work I need to figure out how the circuit works first, as it's not immediately obvious to me. We might just remove the resistor for SUB9V so we disable that.

[rtstorm]

Re: Panasonic TX-37LX85P blink 3 times

well i remove the Q5615 and now it's a 4 red blink.

[tom66]

Re: Panasonic TX-37LX85P blink 3 times

There is no code for 4 blinks. How sure you about that?