Sony KDL-65W850A Dead

[dick_barton]

Re: Sony KDL-65W850A Dead

What is Digital_Standby?

[budm]

Re: Sony KDL-65W850A Dead

12 Ohms for the 12V DC coil is too low, if the relay coil is rated at 1W, then the DCR should be around 140~150 Ohms range, or higher if it is 1/2W relay.

[budm]

Re: Sony KDL-65W850A Dead

What is Digital_Standby?

I did not trace that trace yet.
BTW, that service manual is almost useless.

[dick_barton]

Re: Sony KDL-65W850A Dead

That's obvious when you point it out. Just looked at the Fujitsu data sheet and it does say 11 ohms. Will dig deeper.

Edit
Coil resistance 270 ohms

[budm]

Re: Sony KDL-65W850A Dead

[dick_barton]

Re: Sony KDL-65W850A Dead

I did not trace that trace yet.
BTW, that service manual is almost useless.

+1 And hard work going through it only to find that out.

[kevinm34232]

Re: Sony KDL-65W850A Dead

You won't have any AC voltage on bridge rectifier D6101 on the APS-356 until the relay operates. This is a 12V dc relay. Measue the coil resistance which had diode D6616 across the terminals with your meter set to ohms. It should be 12 ohms.

Edit
Updated coil resistance in later post

Which coil are you referring to, I don't see a D6616?

[kevinm34232]

Re: Sony KDL-65W850A Dead

I did not trace that trace yet.
BTW, that service manual is almost useless.

Yes I agree it's given some info but nothing substantial...

[dick_barton]

Re: Sony KDL-65W850A Dead

Shown in attachment

[Diah]

Re: Sony KDL-65W850A Dead

Yes I agree it's given some info but nothing substantial...

as i wrote at Post No 2. its almost same as 65W955 and the SM useless, so i do suggest you to show us high resolution photo of the MB from both sides and please take out the shield cover out, as the DC _ DC converter at w955 are on the MB not at PWB

[kevinm34232]

Re: Sony KDL-65W850A Dead

You won't have any AC voltage on bridge rectifier D6101 on the APS-356 until the relay operates. This is a 12V dc relay. Measue the coil resistance which had diode D6616 across the terminals with your meter set to ohms. It should be 12 ohms.

Edit
Updated coil resistance in later post

263 ohms. I decided to order a replacement of this APS-356 and had no changes. 259 ohms on replacement board across the pins with D6616.

[kevinm34232]

Re: Sony KDL-65W850A Dead

Welp I got a replacement main board, and now TV responds to power button.

But, plugged in power, pressed power button, got a brief flash of backlights, then went out and front LED flashing green to amber over and over until AC unplugged.. Now no backlight flash at all just same green-amber flashing..

So this is progress, although disappointing.. Time to look at the SM again and see what this means.

EDIT:
[Quick look at SM and nothing describes this symptom, great...]

More info:
In standby, now get 3.3V STBY and REG12V. POWER_ON is also 3.3V. When power button is pressed, main board sends 3.3V to DIGITAL_STBY and BL_ON (relays click then go off in 1-2 secs).

There is a TCON_ON on the PS, that does not get a signal at all from main board during this time.

I then tried another LED power supply (APS-356), and got same results..

This is looking more and more like another bad LED light, or possibly the LED driver board.

[kevinm34232]

Re: Sony KDL-65W850A Dead

Found some info elsewhere which I had hoped to be helpful:

"I have found that on a good working set the BL_ERROR signal wire should read low/ 0V

so to simulate that I simply just grounded the BL_ERROR signal wire off of the connector cable on the G7 board or secondary power supply that powers the LD board"

Unfortunately, this did not force backlights to stay on.

At this point I think it's either the LD board, or bad LEDs.

Anyone know how if I can do any tests on the LD board?
Part # is ST650LD-20S01
The 5 ICs are part # AN37011B

[kevinm34232]

Re: Sony KDL-65W850A Dead

So now (with main board disconnected), I jumped 3.3V to:
POWER_ON
BL_ON
DIGITAL-STBY_ON

This kicks on the 2nd power board (APS-356), but still no backlights.

The voltages on the 2 connectors on APS-356 are as follows:

14 pin connector (to/from LD board):
VLED_VCC = 60.75V
LD_ERR = 0.13V
GL_CTRL = 0.0V
REG12V = 12V

6 pin connector (to/from PS board APS-352):
BL_ERR = 6.17V
LD_ERR = 0.25V
DIGITAL_STB = 3.2V
BL_ON = 3V
REG_12V = 12V

I should mention that while checking voltages when everything was connected normally, occasionally I'd get backlights for a few seconds, and GL_CTRL would be around 1.1V.

[dick_barton]

Re: Sony KDL-65W850A Dead

You have BL_ON which is good but unfortunately BL_ERR is indicating faulty backlights.
Can you measure all 4 VLED_VCC and say what the voltage on all 4 connections are. They may go high when first switched on and then fall back.

You could also measure the primary and secondary resistance of each of the transformers and see if they differ significantly from one another.

You're almost there.

GL_CTRL......Unfortunatley I don't know what that stands for but does it say in the manual?

[kevinm34232]

Re: Sony KDL-65W850A Dead

All 4 are the same.. What is normal voltage for these?

[dick_barton]

Re: Sony KDL-65W850A Dead

Sometimes it says on the circuit board what the led voltage should be. Or it may be in the service manual. Normally when you have a faulty led the voltage on that line is different and is the give away that you have a led fault.

[kevinm34232]

Re: Sony KDL-65W850A Dead

I should be getting some sort of backlights at this point if everything past here is good then, correct? What is the function of the LD board?

[kevinm34232]

Re: Sony KDL-65W850A Dead

Any other tests I can do either from VLED_VCC, or from the wires going into the panel?

[Diah]

Re: Sony KDL-65W850A Dead

Any other tests I can do either from VLED_VCC, or from the wires going into the panel?

with replacement MB and every connected you have LED back light go on then off.. did you watched on the screen SONY Logo ? yes backlight Led shorted..

disconnect the backlight socket from BL driver to LEDs and power on, did it stay on and indicator ON of Led at front of the TV. ? if yes can you see the picture with torch light... yes Led BL shorted or open..

did it go in Standby ? if yes you need to make self diagnose mode via service menu because you have now replacement MB. read the SM. you will find how

hope this help you