LG 42LY95-ZA Power problem.

[PlusCom]

PSU – EAY3273110
Mainboard – EAX36680401 (3)

Have this TV that my friend gave me. It goes from red standby led to green but no screen no sound. I have 5v standby and pwr-on 2v but power supply doesn't turns on. My friend had replaced PSU with used one from ebay one but TV does same exact thing so I'm not sure if that PSU is also bad or the problem is on mainboard. The weird thing is that sometimes it turns on normally and can work from 5 min to whole day and before it stops screen starts flickering and you can hear something like clicking sound which I believe comes where the 2 transformers is. Also when screen flickers you can hear a loud static sound from the speakers. I'll try to take a video later because it's difficult to explain. If someone has any idea what can it be please help.

Readings when TV works fine.
P201 ON OFF
ACD 5.08 5.09
PRR-ON 2.10 0.04
5Vs 5.08 5.12
I-C 3.95 0.01
ERR 5.02 0.00
BRI 0.02 0.00
5Vs 5.08 5.11
DIM 0.03 0.00
6V 6.03 0.12
3.4V 1.06 0.02

P202 ON
19V 18.51
6V 6.08
3.4V 3.48
12V 11.76

P204 ON
24V 24.00
BRI 0.02
I-C 3.95
DIM 0.03
ERR 5.02

[FIXITNOW]

Re: LG 42LY95-ZA Power problem.

check ic901 . Its a 3.3 volt regulator on main board

also check caps in this circuit C970 and c920 can also cause problems,
also check the esr of all the 100uf on top right of main board.

[PlusCom]

Re: LG 42LY95-ZA Power problem.

Update

Finally TV stoped working.Here's the readings with green led but black screen.
p201
ACD 5.08
PRR-ON 2.00
5Vs 5.08 5.12
I-C 3.59
ERR 0.09
BRI 0.78
5Vs 5.08
DIM jumps from 2.48 to 3.28
6V 0.55
3.4V 1.06

P202 ON
19V 0.00
6V 0.55
3.4V 3.49
12V 0.17

[PlusCom]

Re: LG 42LY95-ZA Power problem.

check ic901 . Its a 3.3 volt regulator on main board

also check caps in this circuit C970 and c920 can also cause problems,
also check the esr of all the 100uf on top right of main board.

Thanks mate for your answer.
ic901 looks fine. pin1=0 pin2=3.3 pin3=5
There is no C920, I will check the rest of the caps later.