Acoustic Solutions TV - Stuck on Standby

[claudyu07]

hi guys. this is my first time when i try to touch tv for fix.
i have experience with laptop / pc / xbox / ps3 but today my tv got broken and i want to try to fix it .
Model number : LCD26761HDF
As title describe the problem , is stuck on stand by.
When i have opened , no visible broken capacitors or bleeding capacitors.
I have tested PL816 for output and i got the following :
ST_BY 2.1V
+12V_1 - 3.5V
+5v STBY - ok
+3.3V STBY - ok
+24v - 16v
+12v - 4v
+33v - 15v
+3.3v - ok
+5v - 2.1V
+24V A - 16V
+30V - 16V
I would like to mention is also a clicking Noise every 1 second.

PL802 connector to inverter i get aswell 16V insted of 24.

When Motherboard is disconnected from power, clicking noise it's gone and all points that i have remarked few rows up are showing me proper voltages , only +30V show 24V

Any help will be appreciated .

POWER BOARD : 17PW26-1
MOTHERBOARD : 17MB35-1

Thanks

[budm]

Re: Acoustic Solutions TV - Stuck on Standby

Please start with this:
https://www.badcaps.net/forum/showthread.php?t=39740

[stj]

Re: Acoustic Solutions TV - Stuck on Standby

unplug the power from the mainboard and meter resistance between each of those voltage-points and ground.

[Alastair E]

Re: Acoustic Solutions TV - Stuck on Standby

Ugh--VESTEL VOMIT!

Check all the diodes on that '26.x PSU on the output side....

[ReeceyBurger123]

Re: Acoustic Solutions TV - Stuck on Standby

Common fault with these boards is the diode that generates the 24v fails its labled d893 check that first.

[CapLeaker]

Re: Acoustic Solutions TV - Stuck on Standby

Unplug everything on the PSU and force it on. Measure everything again.

Here is a schematic for the PSU cording to SJ it should have.

[claudyu07]

Re: Acoustic Solutions TV - Stuck on Standby

Thank you all for your answers.
first i will post pictures as budm suggested.
second I have tryed to locate D893 but it's not on board and according to schematics from CapLeaker (Thanks) and it's not on schematics aswell.
I will try force power on the board and make readings Again and then test resistance to ground from all those pins though i don't know what i should get.

Thanks

[ReeceyBurger123]

Re: Acoustic Solutions TV - Stuck on Standby

Thank you all for your answers.
first i will post pictures as budm suggested.
second I have tryed to locate D893 but it's not on board and according to schematics from CapLeaker (Thanks) and it's not on schematics aswell.
I will try force power on the board and make readings Again and then test resistance to ground from all those pins though i don't know what i should get.

Thanks

Sorry my bad, its different on the different models, its labled diode d881 check that.

[CapLeaker]

Re: Acoustic Solutions TV - Stuck on Standby

I couldn't find that D893 yesterday either.
Good idea to disconnect everything and forcing the PSU on. Seems like most of the voltages you measured are low. Maybe you want to check the battery in your DMM.

[claudyu07]

Re: Acoustic Solutions TV - Stuck on Standby

I couldn't find that D893 yesterday either.
Good idea to disconnect everything and forcing the PSU on. Seems like most of the voltages you measured are low. Maybe you want to check the battery in your DMM.

will do now. just doing research how to do it. i have to bridge +5V STBY with PS ON from what i saw on different threads but it's not any PS ON on my board.
I will remove now D881 and test it

Battery on DMM is grand .

[tom66]

Re: Acoustic Solutions TV - Stuck on Standby

If it's not D881, then Q844, on the primary, will sometimes fail leaky. When this fails, the output voltages will bounce around. In my case it had about 300 ohms between collector, emitter and base.

[ReeceyBurger123]

Re: Acoustic Solutions TV - Stuck on Standby

I couldn't find that D893 yesterday either.
Good idea to disconnect everything and forcing the PSU on. Seems like most of the voltages you measured are low. Maybe you want to check the battery in your DMM.

Its d881 my notes were for the 17pw26-4 that I think its labelled different, if not check the primary transistors they sometimes fail and cause messed up voltages.

[claudyu07]

Re: Acoustic Solutions TV - Stuck on Standby

d881 ok. 400 reading on my dmm. wil check now q844 and primary transistors


Q844 is gone. will find replacement and post back if fixed. Thanks you

[ReeceyBurger123]

Re: Acoustic Solutions TV - Stuck on Standby

d881 ok. 400 reading on my dmm. wil check now q844 and primary transistors


Q844 is gone. will find replacement and post back if fixed. Thanks you

Good to hear, hopefully bring that tv back to life also I would advise you replace the gluxon brand capacitors as they probably will fail shortly and bring the set down again.
When I get home I will take a photo of a 17pw26-4 I recapped.

[claudyu07]

Re: Acoustic Solutions TV - Stuck on Standby

Q844 replaced . still same problem.

Test the board again for output voltages on PL816 and all voltages are correct except pin 27 which supposed to be 30V but is only 24V

[ReeceyBurger123]

Re: Acoustic Solutions TV - Stuck on Standby

Q844 replaced . still same problem.

Test the board again for output voltages on PL816 and all voltages are correct except pin 27 which supposed to be 30V but is only 24V

Have you checked the diode behind it ?

[CapLeaker]

Re: Acoustic Solutions TV - Stuck on Standby

what about R1017? D881 and the caps after that?

[ReeceyBurger123]

Re: Acoustic Solutions TV - Stuck on Standby

Can you take some close up photos of the psu, the parts you replaced.

[claudyu07]

Re: Acoustic Solutions TV - Stuck on Standby

d881 OK . R1007 looks like missing???
Capacitors after D881 ok

[ReeceyBurger123]

Re: Acoustic Solutions TV - Stuck on Standby

d881 OK . R1007 looks like missing???
Capacitors after D881 ok

And you check the smd diodes behind the part you replaced, forgot to mention they are on the underside of the board right next to the leads of the part you replaced.