Sony KDL 52w5500 No image, no Backlights

[goulloux]

Re: Sony KDL 52w5500 No image, no Backlights

Oh ok, then I'll wait a bit more before rushing this buy ^^
So from what I understand the diagram show that there's other switch on the inverter board, right ?

But the signal is going from the [Main board] => [Power supply Board] => [Inverter] => [Balancer]

Since I did not see any signal from the [Main board] to [Power supply Board]
The inverter should not be relevant ?
Or am I missing something ?

[budm]

Re: Sony KDL 52w5500 No image, no Backlights

The signals from the main board (BACKLIGHTS and Dim) are routed through the G5 power supply connector and out through another connector to get to the D5 inverter board.
On the G5 power supply board, there is the circuit that can lock out the BACKLIGHTS signal (using OPTO, part of the AC detect which we have already verified that it is OK), then on the D5 board, there is also circuits that will lock out the Backlights signal if the Balancer board error.
So at this point I am not 100% sure if the problem is on the main board or in the D5 Inverter board. We will have to disconnect the protection circuit to find out.

[goulloux]

Re: Sony KDL 52w5500 No image, no Backlights

And if we take in account that the T-CON is not working either
Can the inverter board have an impact on that ?

[audiofreak19]

Re: Sony KDL 52w5500 No image, no Backlights

On mine I checked the fuse on the t con and it got 12v on the main fuse. But that's as far as I went on that.

[goulloux]

Re: Sony KDL 52w5500 No image, no Backlights

But do you get any image on screen ? (in case you don't know it, the LCD may still show a really dark image on the LCD screen, you may need to use a flashlight to see it)

[stretchstudebaker]

Re: Sony KDL 52w5500 No image, no Backlights

HFR is the High Frame Rate convertor, located under the T- Con.
The inverter pcb should have a pin marked inv/on or something similar. This will almost always be a high (sometimes only 2.9 volts or so) and tells the invertor circuit to fire the lamps. The hfr/t-con pcb must be operational before the main CPU puts out the "on", If the on is there, the problem is invertor or lamps. BE careful if you have operational uncovered invertors. Get too close to a transformer or lamp connection and the first thing you'll notice will be the smell of burning flesh (yours)!!! Consult SM or TM for loacation of test points.

[goulloux]

Re: Sony KDL 52w5500 No image, no Backlights

We will have to disconnect the protection circuit to find out.

Hum, will it imply some soldering ? :s

[goulloux]

Re: Sony KDL 52w5500 No image, no Backlights

I have another question poping in my head and this must be realy basic electronic stuff:

Should I be able to see the backlight signal going through the power supply board even if the inverter lock the signal after ?

Basically the question is does a signal can be fired if the circuit is lock somewhere.

[budm]

Re: Sony KDL 52w5500 No image, no Backlights

There is lock out circuit on the master inverter board and also on the power supply board, we have already verify that it is not the opto on the power supply board, so you can disconnect the cable between the power supply board and the master inverter board to see if the BACKLIGHTS signal will be present on the power supply board or not.

[goulloux]

Re: Sony KDL 52w5500 No image, no Backlights

Are you talking about the CN6702 (I guess) or the CN6600 on the inverter (master)

[budm]

Re: Sony KDL 52w5500 No image, no Backlights

Yes, the CN6702 on the master inverter board.
https://www.badcaps.net/forum/showth...t=36482&page=3

https://www.badcaps.net/forum/showth...t=36482&page=3

[goulloux]

Re: Sony KDL 52w5500 No image, no Backlights

ALright just did the test, no change
I don't see any signal going through

[budm]

Re: Sony KDL 52w5500 No image, no Backlights

Do you still get the 13X and follow by the 14X codes when the cable is disconnected?

[goulloux]

Re: Sony KDL 52w5500 No image, no Backlights

Yes, I just chek

[budm]

Re: Sony KDL 52w5500 No image, no Backlights

I am running out of idea to verify for sure if it is the main board problem or not, per post 66, "The hfr/t-con pcb must be operational before the main CPU puts out the "on"" then I would expect to see 14X code first before code 13X.

[goulloux]

Re: Sony KDL 52w5500 No image, no Backlights

Well maybe this is a FILO stack of erros (first in last out)

And if
"The hfr/t-con pcb must be operational before the main CPU puts out the "on"" is accurate, that would mean that you can't have backlights witchout a working T-CON ?
I feel like I have read some people saying that they were geting backlights but a black image (T-Con problem)

[goulloux]

Re: Sony KDL 52w5500 No image, no Backlights

Otherwise, is there any way to test the HFR ?
I've read that this part is inside the LCD screen ... and if it's the problem you should change your tv ^^

[budm]

Re: Sony KDL 52w5500 No image, no Backlights

It is part of the T-CON board.

[goulloux]

Re: Sony KDL 52w5500 No image, no Backlights

I can't find where I read about this HFR being inside the LCD panel and not the T-CON...
Is there any way to test the T-CON
I have done the test to unplug / replug the T-CON connector to see if there's any reaction
But nothing

[budm]

Re: Sony KDL 52w5500 No image, no Backlights

Can you show the picture of the T-CON and model number of the LCD panel?