LG 50PS3000 clicks

[vili23]

hi!
I'm having problems with my LG plazma 50PS300.
I'm suspecting the power supply board EAY60716801.
When I power it on it makes 2 clicks and goes to stand by.
When I turn it on (button or remote) the LED blinks 6 times blue and then turns red.
The coil marked on the picture starts to buzz.
I mesured the voltages and they are all 0 except stby5v which is 5V.
Tried with all board connected to PS and all boards disconnected, its the same.
I also tested all fuses and they are ok.Tested all diodes and i think they are ok (not open or shorted). Also I tried to change the voltage regulator IC301 (STRW6252S) and the red capasitor marked on the picture.
Nothing changed. Please advise me what to do next.
If you need more info please tell and I will provide.
Sorry for my English, not my native language.

thanx

[tom66]

Re: LG 50PS3000 clicks

With Y-sus and Z-sus boards unplugged (all others connected) and power board installed, what voltages do you measure on Vs and Va?

[vili23]

Re: LG 50PS3000 clicks

The voltages are all zero

[vili23]

Re: LG 50PS3000 clicks

Gentle nudge.

[topng]

Re: LG 50PS3000 clicks

It's almost the same fault all the lg check the power resistor, in the main power board.
and transistor ,30v zener diode.

[vili23]

Re: LG 50PS3000 clicks

Can you tell me please where are this elements you are talking about?

[vili23]

Re: LG 50PS3000 clicks

Do you mean the components in this kit?
http://www.ohmsupplies.co.uk/REPAIR-...Y-IC301-FAULTY

I tested them all and changed Ic301 and they are all ok.
This board is driving me crazy

[tom66]

Re: LG 50PS3000 clicks

Did you check VS ON, M5V ON and RL ON signals on main board connector (it goes to power board)?

[vili23]

Re: LG 50PS3000 clicks

I did,they are all 0V except

AC_DET 5V
AUTO_GND 4.1V
KEY_ON 4,5V
STBY5V 5V

[tom66]

Re: LG 50PS3000 clicks

OK, can you get hold of some 100~470 ohm through hole resistors?

[vili23]

Re: LG 50PS3000 clicks

i got them, what's next?

[vili23]

Re: LG 50PS3000 clicks

Hey Tom66
Could you tell me what to jump with this resistors and what scould happen

[tom66]

Re: LG 50PS3000 clicks

Sorry, missed your post.

Please locate a 5V supply (STBY5V pin will do fine) and connect one resistor to VS ON, RL ON and M5V ON. Unplug the connector from the main board end (the connector with the VS ON etc on it)

Then, plug the TV in. Do you see a faint glow from the display panel? Do you measure good Vs and Va on power board?

If so, step 2:

Unplug power to the TV.

On the control board, which is the board below the power board and connects to most of the other boards: jumper the EXT AUTO GEN pins marked 1 and 2 (a small wire works well)

Unplug the LVDS cable which runs between the main A/V board (HDMI inputs etc) and the control board.

Plug the TV back in. Do you get cycling test patterns?

[vili23]

Re: LG 50PS3000 clicks

Hey
I did what you told me but nothing,no glow and no voltages.
What do you think, could it be just the ps board because i'm thinking about purchasing a new one.

[tom66]

Re: LG 50PS3000 clicks

When you do those steps, did you hear a click or two from the power board? Do you measure 17V on the main board connector (unplugged)?

[vili23]

Re: LG 50PS3000 clicks

When i connect the power cable the board clicks two times fast, click-clack
Like it powers on and off right away.
There is no voltage at 17V pin.

[tom66]

Re: LG 50PS3000 clicks

OK, now try with the Y-sustain and Z-sustain unplugged.
Y-sustain is large green board on left hand side of TV.
Z-sustain is large green or beige or orange board on right hand side of TV.
(Both looking from the back.)

[vili23]

Re: LG 50PS3000 clicks

tried with the two boards connected and disconnected and it's the same
just click-clack and no voltages

[tom66]

Re: LG 50PS3000 clicks

Ok, this points to a power board fault.
On the power board, are all fuses good? Use continuity range to test them.

[vili23]

Re: LG 50PS3000 clicks

i ordered a new board,found it on ebay for 26 quid with shipping, i will try with that and see.thanx for the help so far