Sony KDL-43WD750 Turns on, no display

**Diah** · 08-09-2019, 11:47 AM

Re: Sony KDL-43WD750 Turns on, no display

start to upload photo on whole back of the tv to see how boards connected together.. also photo on T-CON.
did you test the T-CON fuse ?
plug in USB stick with JPG photo on the root of it and check the LED indicator of the stick blinking ??

did you try to inter diagnose mode from stand by if it come the screen on

**CapLeaker** · 08-09-2019, 12:29 PM

Re: Sony KDL-43WD750 Turns on, no display

Test the LVDS on the main board with an oscilloscope, while flicking the menu on and off all the time. That will tell you if the main board is good or not.
Check the Tcon that it is getting power and then there are little buck converters on the Tcon, check them too.

**budm** · 08-09-2019, 01:12 PM

Re: Sony KDL-43WD750 Turns on, no display

Need good clear pictures so we can see what we are dealing with.
T-CON is integrated into the LED panel?

**nomoresonys** · 08-09-2019, 04:06 PM

Re: Sony KDL-43WD750 Turns on, no display

Unplug tv from power, unplug cable from powerboard to mainboard leave it unplugged, plug power back into outlet, does anything change?

**nomoresonys** · 08-09-2019, 04:10 PM

Re: Sony KDL-43WD750 Turns on, no display

Kdl's are easy to bork up firmware, try a firmware update, firmware on a flashdrive, some kdl's will update automatically, have tv plugged in, plug in flashdrive turn tv on.

**nomoresonys** · 08-09-2019, 04:14 PM

Re: Sony KDL-43WD750 Turns on, no display

Read the instructions, it might not work without a display, some older kdl's will: https://www.sony.co.uk/electronics/s...loads/00016216

**FrozenHaxor** · 08-10-2019, 05:11 AM

Re: Sony KDL-43WD750 Turns on, no display

Heres a photo of TV's back. Shields off, everything connected.

The fuse on T-CON is good. Should I measure waveforms of any random lines of the LVDS cable with an oscilloscope? Or any particular points there?

T-CON power rails measure good voltages.

As I've mentioned in my first post, this TV stopped working after lightning storm. Would that be a cause of firmware failure? It was probably zapped through DVB-T tuner.

**nomoresonys** · 08-10-2019, 05:19 AM

Re: Sony KDL-43WD750 Turns on, no display

Read much???????

**FrozenHaxor** · 08-10-2019, 06:01 AM

Re: Sony KDL-43WD750 Turns on, no display

Originally posted by nomoresonys

Unplug tv from power, unplug cable from powerboard to mainboard leave it unplugged, plug power back into outlet, does anything change?

There is no power board in this model, it uses 19,5V external brick that plugs straight into the logic board.

Originally posted by nomoresonys

Kdl's are easy to bork up firmware, try a firmware update, firmware on a flashdrive, some kdl's will update automatically, have tv plugged in, plug in flashdrive turn tv on.

Originally posted by nomoresonys

Read the instructions, it might not work without a display, some older kdl's will: https://www.sony.co.uk/electronics/s...loads/00016216

According to those instructions I have to navigate through many menus and options to update the firmware, which is impossible given current state of the TV.

**nomoresonys** · 08-10-2019, 08:38 AM

Re: Sony KDL-43WD750 Turns on, no display

One possible reset method:
Unplug the TV. Hold down the "Power" and "Down" buttons at the same time and plug the power back into the outlet while holding the buttons for 30 seconds. When a green LED light comes on, release the buttons. Wait while the TV reboots multiple times and runs through the reset cycle. Those diy reflows are a temporary fix, most don't last past a few months.

**Diah** · 08-10-2019, 09:22 AM

Re: Sony KDL-43WD750 Turns on, no display

Originally posted by FrozenHaxor

The fuse on T-CON is good. Should I measure waveforms of any random lines of the LVDS cable with an oscilloscope? Or any particular points there?
T-CON power rails measure good voltages.
As I've mentioned in my first post, this TV stopped working after lightning storm. Would that be a cause of firmware failure? It was probably zapped through DVB-T tuner.

1- remove the tuner board from MB and check menu come out ?
2- i mentioned before to inter diagnose mode from stand by state to check it will come the screen.
3- as its use external power adapter. the Panel will have one Fuse on the left side of its Tap.

**FrozenHaxor** · 08-12-2019, 06:44 AM

Re: Sony KDL-43WD750 Turns on, no display

Originally posted by nomoresonys

One possible reset method:
Unplug the TV. Hold down the "Power" and "Down" buttons at the same time and plug the power back into the outlet while holding the buttons for 30 seconds. When a green LED light comes on, release the buttons. Wait while the TV reboots multiple times and runs through the reset cycle. Those diy reflows are a temporary fix, most don't last past a few months.

Doesn't look like this method works on this particular TV, it just turns on and keeps blinking while I hold the buttons.

Originally posted by Diah

1- remove the tuner board from MB and check menu come out ?
2- i mentioned before to inter diagnose mode from stand by state to check it will come the screen.
3- as its use external power adapter. the Panel will have one Fuse on the left side of its Tap.

1 - The board behaves exactly the same without the tuner board, same amperage draw.
2 - Can you tell me the combination to try and enter this mode?
3 - Interesting, I will investigate that. Is that fuse for display or backlight though? Because backlight works.

**FrozenHaxor** · 08-21-2019, 02:53 AM

Re: Sony KDL-43WD750 Turns on, no display

Right, so the motherboard was replaced, now the TV shows an image and appears to be working.

BUT

None of the channel programming functions work. When trying to search for DVB-T channels, the TV shows 0 channels found for a brief time and then restarts. Won't even attempt to find any analog ones either. I have updated the firmware successfully, but that didn't help. What could be wrong now?

This is the tuner board I have: (RE243ZP)

**nomoresonys** · 08-21-2019, 05:26 AM

Re: Sony KDL-43WD750 Turns on, no display

.

**nomoresonys** · 08-21-2019, 05:29 AM

Re: Sony KDL-43WD750 Turns on, no display

Wonder if the tuner is bad, maybe try swapping your old tuner to the new board.

**FrozenHaxor** · 08-21-2019, 05:34 AM

Re: Sony KDL-43WD750 Turns on, no display

I have bought a new tuner board, it behaves identically to the old one. If I turn it on without a tuner board in, all the tuning options are correctly grayed out so it does communicate with it at least in some way.

**nomoresonys** · 08-21-2019, 05:38 AM

Re: Sony KDL-43WD750 Turns on, no display

You have tv set to the correct source during tuning attempt?

**FrozenHaxor** · 08-21-2019, 05:41 AM

Re: Sony KDL-43WD750 Turns on, no display

Seems like it does not make a difference which source I chose, still hangs and reboots when enabling any tuning option.

**FrozenHaxor** · 08-21-2019, 06:00 AM

Re: Sony KDL-43WD750 Turns on, no display

I think this board is defective. It is impossible to turn off this TV - after I turn it off, it boots back on in several seconds. Oh ffs I'm so annoyed with this repair.

Sony KDL-43WD750 Turns on, no display

Sony KDL-43WD750 Turns on, no display

Comment

Comment

Comment

Comment

Comment

Comment

Comment

Comment

Comment

Comment

Comment

Comment

Comment

Comment

Comment

Comment

Comment

Comment

Comment

Related Topics