4 Blink Error Help: Sony Bravia KDL-65W850A

[Gearheadski]

When I power the TV on, usually nothing happens, it clicks, and then it shuts off and the red light blinks 4 times. Sometimes the backlights turn on for a few seconds, flicker, and then it powers itself off. I was able to access the service menu screen once, and it showed numerous LD_ERR instances. I have since replaced the backlights and the LD Board (part #ST650LD-20S01), but have not had any success - still the same error code. I've also tried disconnecting and grounding both the LD_ERR and BL_ERR wires to bypass the error, but that didn't work either. Any ideas of what the problem is and how it can be fixed?

[nomoresonys]

Re: 4 Blink Error Help: Sony Bravia KDL-65W850A

ok, so with tv unplugged from power, unhook both flat ribbon cables from the mainboard, as a precaution let the ends rest on a piece of cardboard or paper to be sure they do not contact any metal, then plug power cord back in and see if you still have the 4 blinks.

[R_J]

Re: 4 Blink Error Help: Sony Bravia KDL-65W850A

With everything connected, locate and check the voltage on JL9112 on the rear of the BA2 board

Here are two ther threads on this model, one has the service manual
https://www.badcaps.net/forum/showth...ht=kdl-65w850a
https://www.badcaps.net/forum/showth...ht=kdl-65w850a

[Storyteller12]

Re: 4 Blink Error Help: Sony Bravia KDL-65W850A

Sony tv with 4 blink code is led problem. Have you confirmed your new leds work?
Unplug the main board from the backlight driver board ( blue tabbed) and plug the tv in let us know what happens with the backlights? Do they go through a test pattern? And do they stay on after test pattern or turn off?

[RJARRRPCGP]

Re: 4 Blink Error Help: Sony Bravia KDL-65W850A

2014-built, which I suspect many don't do as well as the 2009-built one that my brother-in-law has.

He will be pissed, if his old Sony Bravia fails.

[nomoresonys]

Re: 4 Blink Error Help: Sony Bravia KDL-65W850A

ok, so what voltage do you have on those error pins with things hooked up as normal? Check both in standby and when you hit power on.

[Gearheadski]

Re: 4 Blink Error Help: Sony Bravia KDL-65W850A

Thank you all for your replies and help.

@nomoresonys: I unhooked the ribbon cables from the mainboard. The result was 1 long blink followed by 2 short blinks, then followed by a succession of 5 short blinks. No backlights.

@R_J: The measured voltage on JL9112 was 1.11v.

@Storyteller12: I don't have an LED tester, so I wasn't able to confirm the new LEDs worked, I just presumed they are new and work. I unplugged the mainboard from the led driver board: The backlights would not power on, but the TV didn't power down with an error either.

@nomoresonys: Here are the voltage readings:
LD_ERR: 2.58v power on / 0.24v in standby
BL_ERR: 4.55v power on / 6.19v in standby

[R_J]

Re: 4 Blink Error Help: Sony Bravia KDL-65W850A

The measured voltage on JL9112 was 1.11v.

This would suggest, going by the manual? that the fault is not with the B* board and is likely with the led's them self. You should be able to operate the tv without the lcd installed so you can see what the led strips are doing, ie one led flickering etc.

It is always best to confirm the backlights are operating properly before reinstalling the lcd and diffuser sheets to avoid damaging the lcd through repeated removals

[lotas]

Re: 4 Blink Error Help: Sony Bravia KDL-65W850A

For some Sony models, the backlight will not start without a connected panel, it will give an error "5".

[nomoresonys]

Re: 4 Blink Error Help: Sony Bravia KDL-65W850A

Thank you all for your replies and help.

@nomoresonys: I unhooked the ribbon cables from the mainboard. The result was 1 long blink followed by 2 short blinks, then followed by a succession of 5 short blinks. No backlights.

@R_J: The measured voltage on JL9112 was 1.11v.

@Storyteller12: I don't have an LED tester, so I wasn't able to confirm the new LEDs worked, I just presumed they are new and work. I unplugged the mainboard from the led driver board: The backlights would not power on, but the TV didn't power down with an error either.

@nomoresonys: Here are the voltage readings:
LD_ERR: 2.58v power on / 0.24v in standby
BL_ERR: 4.55v power on / 6.19v in standby

Yes, bl_err should probably be around 0 volts at some point, that's if there's no problem. I would check them.

[nomoresonys]

Re: 4 Blink Error Help: Sony Bravia KDL-65W850A

In the bottom thread RJ linked, Budm said the bl-err should be around 3 volts in standby and near 0 when powered on and tv working correctly.

[Gearheadski]

Re: 4 Blink Error Help: Sony Bravia KDL-65W850A

For some Sony models, the backlight will not start without a connected panel, it will give an error "5".

I suspect this will be the case.

I was really hoping to avoid having to tear it all apart and remove the panel again. In the case that the LEDs don't power on with the panel disconnected, is there a way to test them without an LED tester? The LEDs rarely power on as is, and when they do it's only for a couple seconds.

Also, I find it strange that the BL_ERR voltage is off, but the service menu screen hadn't registered any BL_ERR errors, only LD_ERR.

[Storyteller12]

Re: 4 Blink Error Help: Sony Bravia KDL-65W850A

If you replaced the backlights and the LD board only other thing related to the 4 blink error is the backlight inverter board. Need to test it to confirm it’s not the problem

[Gearheadski]

Re: 4 Blink Error Help: Sony Bravia KDL-65W850A

Okay, so I was able to check the newly installed backlights, and one of the strips was bad. Only half the lights on that strip worked. So I replaced the bad strip, and I'm still getting the same error. I checked all the backlights several times and they all are working. I replaced the LD board: no change.

I'm stumped. Could it be a bad power board? Or a bad t-con board? At this point I'm just throwing money at it guessing which board to replace next.

@Storyteller12: I'm not sure which board is the backlight inverter. Can you tell me which board that is or what I should be looking for?

[nomoresonys]

Re: 4 Blink Error Help: Sony Bravia KDL-65W850A

Maybe something got borked up, can you try a firmware update/pair with a 2gb or less thumb drive. How is the bl_err voltages now both on and off.

[lotas]

Re: 4 Blink Error Help: Sony Bravia KDL-65W850A

It is necessary to change not one led strip that burned out, but all (for a new complete set).
LED Driver is 1-888-652-11.

[Gearheadski]

Re: 4 Blink Error Help: Sony Bravia KDL-65W850A

Maybe something got borked up, can you try a firmware update/pair with a 2gb or less thumb drive. How is the bl_err voltages now both on and off.

I haven't tried a firmware update yet. I still have the panel removed.

So something weird happened. It turns out the new led strips I installed were all good. When I removed the panel to check the new strips and saw that one was bad, I ordered a new strip. I just installed it and it worked fine for about 5 seconds. Then the lights flashed a few times, and a section of lights on the new strip burned out - the same section that wasn't working on the previous strip that I thought was bad.

I checked all of the old strips and they're all still good, no burned out bulbs or anything. When I plug one of the old strips in place of the new strip that burned out, the lights stay on, at least for awhile. Also, the new led strips are noticeably brighter than the old strips.

So now I'm wondering if it might be a voltage issue, maybe with the power board.

I checked the voltage on both the BL_ERR and LD_ERR, and they're reading 6.19v and 0.24v, respectively, in BOTH standby and on (but I do have the panel removed and disconnected from the t-con board, so I don't know if that affects it).

[Gearheadski]

Re: 4 Blink Error Help: Sony Bravia KDL-65W850A

It is necessary to change not one led strip that burned out, but all (for a new complete set).
LED Driver is 1-888-652-11.

I did replace all the old strips. One of the new strips immediately burned out (a portion of lights on the strip). I then replaced it with another strip and the same thing happened. Oddly, when I plug in an old strip, it seems to work (see my post above).

I thought the LED Driver is 1-895-465-11 (ST650LD-20S01). The part you mentioned is the K board, which I'm not sure of its function.

[lotas]

Re: 4 Blink Error Help: Sony Bravia KDL-65W850A

Apparently my mistake, I didn’t look at the photo in the first post, when I entered the led driver in the search engine, I gave out this board, yes, the blue board 1-895-465-11 (ST650LD-20S01) is right, this is the led driver, then the strip immediately burns out LEDs, rather, one chip has broken through and the maximum voltage is supplied to this LED channel or not high-quality new LEDs (not original).

[Gearheadski]

Re: 4 Blink Error Help: Sony Bravia KDL-65W850A

I was able to update the firmware to the latest version. No change. Still the same problems after the update.