LG 42PX3RVA no picture

[caspermccormack]

Hello, I have a fault in the above tv, when i stripped it down i seen that the y-sus had a blown fuse which led me to believe that the module was also shot too. I have replaced the module and the fuse but still no picture, I have measured the AC detect and it is 4.41 stand by and 4.42 while on. All other voltages are correct coming from the PSU.

Any Ideas????

here is a pic of the damage on the module

[caspermccormack]

Re: LG 42PX3RVA no picture

Tv has sound but no picture.

[tom66]

Re: LG 42PX3RVA no picture

AC detect is OK, because you have sound PSU is OK, problem is likely other fault on Y-sus, check for 200V Vs.

[caspermccormack]

Re: LG 42PX3RVA no picture

AC detect is OK, because you have sound PSU is OK, problem is likely other fault on Y-sus, check for 200V Vs.

Thanks Tom,

187.7 on Vs , sticker says 187v,

[tom66]

Re: LG 42PX3RVA no picture

OK, check for shorts on Y-sustain. From either end of fuse to ground / chassis.

[caspermccormack]

Re: LG 42PX3RVA no picture

[QUOTE=tom66;277158]OK, check for shorts on Y-sustain. From either end of fuse to ground / chassis.


Checked that, no shorts.

[tom66]

Re: LG 42PX3RVA no picture

Any glow from screen in dark room?

[caspermccormack]

Re: LG 42PX3RVA no picture

No tom, nothing at all.

[tom66]

Re: LG 42PX3RVA no picture

I cannot be sure if it is the control board or the Y-sustain. You would need a scope to verify if the control board is functioning.

[caspermccormack]

Re: LG 42PX3RVA no picture

I cannot be sure if it is the control board or the Y-sustain. You would need a scope to verify if the control board is functioning.

Got another tv today to look over and it's the same model as this one I have. I changed over the Y-Sus boards and my one is now working again. So know I know it is the Y-Sus. I have checked over for shorts on the module and found none. So what else can I look for to the board? It doesn't shut off the tv, and the sound is present.


Now, with the good Y-Sus installed back into the TV that I got today, I have a bad picture, lots of ghosting and speckels on the whole screen, What would be the solution to rectify this kind of fault??

Cheers boys!

[tom66]

Re: LG 42PX3RVA no picture

See
https://www.badcaps.net/forum/showpo...29&postcount=7

In particular, adjustment of potentiometers.

However, problem is likely TV is in need of new control board or software flashing.

[caspermccormack]

Re: LG 42PX3RVA no picture

See
https://www.badcaps.net/forum/showpo...29&postcount=7

In particular, adjustment of potentiometers.

However, problem is likely TV is in need of new control board or software flashing.

Sound Tom, nice one for your input!

I'll try that tomorrow. I may check over the faulty Y-Sus board for those voltages to make sure they are there. Is there any other component on the y-sus that I may be able to test and get it back working?