Rep: 11
1
I get no picture and 4 flash of the red light and tv swiches off. I have disconnected CN01 from the P board, breaking the link to the display panel and now get everything apparently working. Is anyone able to explain this? Do I have a problem with the P board or the LED backlight?
Is this a good question?
Rep: 452.8k
11
367
1.4k
Hi @robt69695
According to the service manual for the TV a 4 blink error code could be either the A board, P board or XS board.
It's interesting that there's no schematic for the P board, however I think that there may be a wiring pinout of the CN01 connector on p.66 but no further description as to what it does.
With the TV turned on you could always perform a self check test as shown on p.12 and see if that shows anything.
There is also a voltage reference test point chart on p.11 as well.
Was this answer helpful?
Thanks. I will try the self test. What puzzles me is that the TV works with CN01 disconnected. I'd like to isolate each of the wires in CN01 individually but that's going to mean taking a pair of cutters to it then reconnecting. Might as well I suppose.
Before cutting them check for any voltages on the wires when plugged in and out
As I said I thought that there was a pinout for CN01 on p.66 but maybe that's not it.
Looking further there's a CN0100 connector on p.24 for "service adjustments" but it is shown as being on the A board but it is not shown on the board layout diagram on p.9 as all the A board connectors are designated as "A xx" unless it's there and just not shown.
I found service manual for THL37D25 which has detailed block diagram of P board showing LED current control circuitry. I assume this is similar. It shows pin connection on CN01/2 and all the cathode connections from the panel appear to be linked. Voltmeter tonight to check 174v.
Rep: 784.7k
1.1k
894
2.3k
@robt69695 post some pictures of your boards with your question. That way we can see what you see. CN01 goes to the panel or to the backlight. This sounds like a backlight issue more then a shortened panel.
The 4 blink code is pretty generic and just refers to missing Sub_F_ 12V line. If you disconnect the backlights and it starts it's your backlight array.
Was this answer helpful?
Past 24 Hours: 0
Past 7 Days: 0
Past 30 Days: 2
All Time: 53
2 Comments
@robt69695 just out of curiosity why did you disconnect it?
by oldturkey03
My guess was that the screen is the problem making the TV destined for the tip, but wanted to check if it is a pcb issue and so fixable. So I disconnected CN01 and CN02 hoping to eliminate the screen. Then found only CN01 caused the problem. TV seems to work OK but would like to understand what's going on and if I can use it without CN01 connected. Seems to be either a screen issue or the protection circuit on P board - but which!
by Rob T