Panasonic 55DX600u repair help - no display fast green then slow red led flash

[fixxy88]

Hi everyone. I've been given a dead Pana 55DX600u that I hope to save from landfill. I suspect the tcon board or UC1 on that board.

Set will flash green led and attempt to start, backlight gives a brief flash then set shuts down and red led flashes slowly. Voltages out of PSU look ok. TCon board gets 12v at fuse when attempting to start and 3.3v on L1 but main IC gets warm very quickly (heatsink/cover removed, felt with back of hand) during the second or two the 12v is applied before PSU shuts down. TVS diodes on lvds input lines are not shorted, no caps appear to be shorted.

If I attempt to start TV with TCON lvds disconnected the led will stay green.

Is UC1 on TCON board likely dead? Any further assistance would be hugely appreciated.

[nomoresonys]

Re: Panasonic 55DX600u repair help - no display fast green then slow red led flash

if flashing red and green try to update the firmware.

[lotas]

Re: Panasonic 55DX600u repair help - no display fast green then slow red led flash

How many times does the Power LED flash?

[fixxy88]

Re: Panasonic 55DX600u repair help - no display fast green then slow red led flash

if flashing red and green try to update the firmware.

Once it shuts down power to the TCON it just flashes very slow red.

How many times does the Power LED flash?

I stopped counting at 15 or so. It was flashing very slowly - is this the normal behaviour for flashing a fault code?

Thanks guys :-)

[lotas]

Re: Panasonic 55DX600u repair help - no display fast green then slow red led flash

Power LED Blinking timing chart

[fixxy88]

Re: Panasonic 55DX600u repair help - no display fast green then slow red led flash

Power LED Blinking timing chart

Thanks! I'll put the TCON board back in and count again. Appreciate your help :-)

[Diah]

Re: Panasonic 55DX600u repair help - no display fast green then slow red led flash

backlight gives a brief flash then set shuts down

it tell the BL issue.... as for BL no error code at Panasonic.... and this brand famous with cheap BL strips socket which always get burn / Mild

+ LVDS disconeccted = BL On signal OFF

[fixxy88]

Re: Panasonic 55DX600u repair help - no display fast green then slow red led flash

it tell the BL issue.... as for BL no error code at Panasonic.... and this brand famous with cheap BL strips socket which always get burn / Mild

+ LVDS disconeccted = BL On signal OFF

Thanks Diah. Can you explain the BL issue and how to confirm?

I just tried counting LED flashes again and it just keeps slowly flashing, at around 3 sec each flash, I stopped counting at 30 flashes.

[Diah]

Re: Panasonic 55DX600u repair help - no display fast green then slow red led flash

at time you disconnect the lvds .. you have solid green... but no BL.... or u have BL at this test?

[fixxy88]

Re: Panasonic 55DX600u repair help - no display fast green then slow red led flash

at time you disconnect the lvds .. you have solid green... but no BL.... or u have BL at this test?

This is correct. With lvds disconnected I get solid green but no BL flash or any BL at all. With lvds connected I get very short BL flash then shutdown and slow flashing red LED.

[Diah]

Re: Panasonic 55DX600u repair help - no display fast green then slow red led flash

so read again my perviouse post#7
LVDS disconeccted = BL_On signal OFF ( MB will ignore and didnt send BL_ON signal ) because no need ... no T-CON / LCD in system )
LVDS connected ( normal state ( MB will send BL_ON signal )... BL failed rMB register error ... this BL errpor not designed with Panasonic error chart.

hope now its clear for you

[fixxy88]

Re: Panasonic 55DX600u repair help - no display fast green then slow red led flash

so read again my perviouse post#7
LVDS disconeccted = BL_On signal OFF ( MB will ignore and didnt send BL_ON signal ) because no need ... no T-CON / LCD in system )
LVDS connected ( normal state ( MB will send BL_ON signal )... BL failed rMB register error ... this BL errpor not designed with Panasonic error chart.

hope now its clear for you

I understand that part. Could you explain the actual BL fault a bit more if have time? The bl internal connectors fail? Thanks!

[Diah]

Re: Panasonic 55DX600u repair help - no display fast green then slow red led flash

internal connectors fail or short.
show us the BL socket on PWB clear and focused photo please

[lotas]

Re: Panasonic 55DX600u repair help - no display fast green then slow red led flash

Thanks Diah. Can you explain the BL issue and how to confirm?

I just tried counting LED flashes again and it just keeps slowly flashing, at around 3 sec each flash, I stopped counting at 30 flashes.

You get the error "1" - BL SOS (blink once - pause 3 seconds, blink once again - pause, ...)

[Diah]

Re: Panasonic 55DX600u repair help - no display fast green then slow red led flash

You get the error "1" - BL SOS (blink once - pause 3 seconds, blink once again - pause, ...)

i don't think so..... he may got 10 blink fast... Panasonic BL error code never being correct... because the issue if the socket burn / mild will have different behavior

[fixxy88]

Re: Panasonic 55DX600u repair help - no display fast green then slow red led flash

internal connectors fail or short.
show us the BL socket on PWB clear and focused photo please

Both BL sockets on power board are perfect - would you still like a photo? If I disconnect both, LED blink fault behaviour is the same but no BL flash. If I disconnect one BL connector, I get no BL flash but same shutdown and red slow led. If I disconnect other, I get BL flash and same shutdown and red slow led.

At first power I get solid green, fast green flash about 10 times, small pause, about 5 fast green, then red slow continuous.

[Diah]

Re: Panasonic 55DX600u repair help - no display fast green then slow red led flash

Man... i hate to write and answer threat when OP just follow his head... then no need for asking help.
i asked for photos to tell you how to test... not to check if they are looking good or not.. the issue you have deep under the LCD at LED strips socket. that's all... good luck.

[fixxy88]

Re: Panasonic 55DX600u repair help - no display fast green then slow red led flash

Man... i hate to write and answer threat when OP just follow his head... then no need for asking help.
i asked for photos to tell you how to test... not to check if they are looking good or not.. the issue you have deep under the LCD at LED strips socket. that's all... good luck.

I apologise and understand your frustration. I read the previous message about the connector burn and mistakenly thought that is what you were looking to see. I will take a clear photo and post it in a few minutes. Again sorry for the frustration and I appreciate the time you spend here helping people, you do a great job :-)

[fixxy88]

Re: Panasonic 55DX600u repair help - no display fast green then slow red led flash

internal connectors fail or short.
show us the BL socket on PWB clear and focused photo please

Here are some photos:

[fixxy88]

Re: Panasonic 55DX600u repair help - no display fast green then slow red led flash

I think this is looking like the same problem that I have. https://www.youtube.com/watch?v=X1bFG2j-Uts