Sony KD 49X8307C

[Donny2derby]

Hi again all. Picked the above model up a couple of days ago. Information was that it just stopped working all of a sudden. Was from a nice house with no kids or pets and no reason to think it's suffered impact damage.

Working my way through it. I get a flashing silver light on the front which indicates an attempt to start?? Then it turns off and doesn't attempt to reboot.

Had the back panel off and with the plugs disconnected to the backlights, on the connectors I'm getting 63v DC on CN 6801 and 4.0v DC on all pins on CN 6802. All except the not connected ones I should add.

So am I right to think the backlights have failed?

Pictures and videos below.

Thanks in advance.

won’t allow me to upload a video.

[Donny2derby]

To add to this. With an LED tester across the CN6802plug I’m dropping 200v across the plug. I.e I have 300v on my tester then it drops down to 100v with the leads connected across the plug. Seems an awful lot of voltage to drop.

Am I onto the correct issue do we think? Where’s my boy Diah at??

[Donny2derby]

Anybody able to add anything to this? Does this sound like faulty backlights?

With my LED tester on the plug for them I can see some of them light up but that’s without the bezel etc removed and the backlights physically visible. If there’s even one out I wouldn’t get a picture on screen due to no feedback would I?

Or am I barking up the wrong tree?

[lotas]

If the problem were with the backlight, then the TV would display an error and the red LED would blink 6 times.

[Diah]

if you did the LED tester on the plug of LED when it disconnected from the power boards socket and it read so high... mean you have shorted LED which still in tact... TV will not register error at LED short remain in tact.... i think yours Panel LG one... which use different LED unit-

if you use touch light on screen you may able to see sign of picture on it

[lotas]

Sony, with many protections, will display an error in case of any malfunction of the backlight (current, breakage...).
Most likely the problem is in the motherboard, eMMC.


The voltage at the backlight output must be measured between +OUT1 and -OUT1 -1,-2,-3 and between +OUT2 and -OUT2-1,-2,-3. there should be 6 readings.

[Donny2derby]

Ahhh that’s fantastically helpful lotas. Thanks a lot. The tv is currently reassembled at the minute but when I open it up again I’ll do the test you suggested.

What would be a test to see if the mother board/emmc is faulty? Can this be done with a multimeter?

Thanks both for your help.

[Diah]

Sony, with many protections, will display an error in case of any malfunction of the backlight (current, breakage...).
Most likely the problem is in the motherboard, eMMC.


The voltage at the backlight output must be measured between +OUT1 and -OUT1 -1,-2,-3 and between +OUT2 and -OUT2-1,-2,-3. there should be 6 readings.

that's true if BL issue there will be error blink..... but for some how at android Sony will be not standard... many years before this post after repair sold it to friends. years later he come to me told me there are no reaction or picture.. visit him at home and it was same this threat... look it turn on but no BL no sound... i did hard reset by press joystick and pushed it down while it plugged in wall .. release the push after the front LED change from white to green... it restarted 2 time and at end i can hear start music but no BL at all... with my mobile light i can notice the first install screen... thought no sign of any error blinking..

yes it could be glitch at firmware on eMMC .. but the subject of error code 5 / 4 blink not standard to me.at Sony Android.
we have also other threat with 55 from USA he solved it with same way and PKG firmware.

[Donny2derby]

So we're not entirely sure of the issue is backlight or firmware then? Is that what you lads are telling me?

If I try the hard reset you suggest Diah, what do I need to do? Plug set in and press standby button until the standby light changes from white to green?

And then check to see if I can see a picture with a flashlight? Or hear sound?

If I remember correctly the chap I bought the set from did say he had tried to do some form of reset. Will try it anyway.

[lotas]

Hard reset : We press the power and volume down buttons of the Sony KD-49X8307C at the same time, we keep them pressed and we connect the Sony television to the electrical current.

[Diah]

So we're not entirely sure of the issue is backlight or firmware then? Is that what you lads are telling me?

If I try the hard reset you suggest Diah, what do I need to do? Plug set in and press standby button until the standby light changes from white to green?

And then check to see if I can see a picture with a flashlight? Or hear sound?

If I remember correctly the chap I bought the set from did say he had tried to do some form of reset. Will try it anyway.

No. first press it and push it down.... keep this position then plug it at wall..... release your finger push only after the front change from white to green... then dont do any things it could restart twice or more

[Donny2derby]

Thanks lads. Will let you know how I get on tomorrow.

[Donny2derby]

Apologies for the delay in getting back to you lads. I have a heavily pregnant mrs in the house who for some reason is expecting me to take care of her as a priority over fixing tv’s! Anyhow.

lotas the backlight readings you asked for all give 3v AC.

ive also tried the hard reset but didn’t get anything much happen at all. Do I need to use the buttons on the telly or is it ok to do it on the remote?

[Donny2derby]

Is it worthwhile checking voltages on this plug Diah lotas??

[Donny2derby]

Ok. My first attempt at a hard reset was clearly wrong. Because this time I have managed to get to the stage where the standby light turns green. I then let go. And I’m waiting for something to happen. But nothing for 2 or 3 minutes. Standby light is not illuminated at all. No signs of picture or audio.

[Donny2derby]

Ok lads I’ve tried the hard reset twice now. But still when I go to power the set up with the remote the white standby light comes on briefly then goes off again. So no apparent improvement from the hard reset. I will await patiently further advice.

And if the tv is fixed, I will name my first born child Diah or Lotas!

[nomoresonys]

You aren't really going to do that to the poor lad are you?

[nomoresonys]

It does seem to be acting like bad eMMC.

[Donny2derby]

You aren't really going to do that to the poor lad are you?

You think nomoresonys has more of a ring to it? So it shall be!

[Donny2derby]

It does seem to be acting like bad eMMC.

is there a test/fix for this? Nomoresonys Snr 😁