LG 50" Plasma 50PS30-UB powers on, no picture, no sound

[Hamie]

Re: LG 50" Plasma 50PS30-UB powers on, no picture, no sound

Can you upload a picture of your control board please.
(Small board below the power supply)

[douellette88]

Re: LG 50" Plasma 50PS30-UB powers on, no picture, no sound

Picture has been attached, thanks

[douellette88]

Re: LG 50" Plasma 50PS30-UB powers on, no picture, no sound

Bump

[niblettr]

Re: LG 50" Plasma 50PS30-UB powers on, no picture, no sound

Does the led on the control board flash about once a second when tv is on?
Also, are you sure there is no sound? Did you used to get a bootup sound when turning on the tv (when the TV used to work)?

[douellette88]

Re: LG 50" Plasma 50PS30-UB powers on, no picture, no sound

The light appears to be steady green. As for sound, I don't know which input it is on so I don't know which one to test on. I got it for free to repair. However I did try cranking the volume up to see if I heard static but I didn't

[niblettr]

Re: LG 50" Plasma 50PS30-UB powers on, no picture, no sound

ok, not sure about this one (cant find a service manuls)
Try (with TV power off) disconnect LVDS cable from main board to control board. Bridge pins 3 and 4 on the connector labelled Auto Gen (bottom left hand corner of control PCB)
Turn on TV, wait a few seconds, does any led flash on the control board. If yes, take a peek at the plasma display. Does it show up test patterns? If you do get test pattern, then it looks like fault might be on main board.

[douellette88]

Re: LG 50" Plasma 50PS30-UB powers on, no picture, no sound

Okay will have to try, How do I bridge the pins?

[niblettr]

Re: LG 50" Plasma 50PS30-UB powers on, no picture, no sound

your girlfriend/wife's tweezers
Or, if you have no tools, roll up a small ball of aluminium foil and jam it between the 2 pins (make sure it doest short elsewhere)

[douellette88]

Re: LG 50" Plasma 50PS30-UB powers on, no picture, no sound

your girlfriend/wife's tweezers
Or, if you have no tools, roll up a small ball of aluminium foil and jam it between the 2 pins (make sure it doest short elsewhere)

It doesn't have the pins labeled for what number is what pin and I'm too f***** afraid of jumping the wrong 2 pins and having it explode in my face. I briefly tried jumping the two on the right side of the plug but nothing seemed to change.

[douellette88]

Re: LG 50" Plasma 50PS30-UB powers on, no picture, no sound

ok, not sure about this one (cant find a service manuls)
Try (with TV power off) disconnect LVDS cable from main board to control board. Bridge pins 3 and 4 on the connector labelled Auto Gen (bottom left hand corner of control PCB)
Turn on TV, wait a few seconds, does any led flash on the control board. If yes, take a peek at the plasma display. Does it show up test patterns? If you do get test pattern, then it looks like fault might be on main board.

Also, if I DO get the test pattern that means bad main board?
But if I DON'T get the test pattern does that mean bad logic/control board?

Wouldn't the green light on the logic board mean that board and everything before it is good?

[niblettr]

Re: LG 50" Plasma 50PS30-UB powers on, no picture, no sound

Answer to first question, yes, more than likely like I said before.
second question, not necessarily.
3rd question, not sure what steady green light means, sorry. It could just mean that power is being received and that's it. There are 2 leds on the control board.

Ok, no need to panic. Its just a diagnostic port (VERY low power) nothing will blow up in your face. On my 4 pin diagnostic port I tried every combination of pins to see if I get different test patterns. I would try the 2 right hand side ones first.

[niblettr]

Re: LG 50" Plasma 50PS30-UB powers on, no picture, no sound

It doesn't have the pins labeled for what number is what pin and I'm too f***** afraid of jumping the wrong 2 pins and having it explode in my face. I briefly tried jumping the two on the right side of the plug but nothing seemed to change.

Sorry, I missed the last bit, ok try the other 2.

[niblettr]

Re: LG 50" Plasma 50PS30-UB powers on, no picture, no sound

It doesn't have the pins labeled for what number is what pin and I'm too f***** afraid of jumping the wrong 2 pins and having it explode in my face. I briefly tried jumping the two on the right side of the plug but nothing seemed to change.

Did you have the LVDS cable disconnected? Also, did you give it a while to wait for TV to boot up.

[niblettr]

Re: LG 50" Plasma 50PS30-UB powers on, no picture, no sound

Also, try (with power disconnected) disconnect the ribbon cable from control board to Ysus (top left of control board) then power on TV. Do any leds fash on the control board?

[douellette88]

Re: LG 50" Plasma 50PS30-UB powers on, no picture, no sound

With lvds unplugged and tv fully booted, I tried jumping the first two, middle two, and last two. Nothing changes with any - steady green light (below larger chip on left side) and no test pattern. Have not tried disconnecting cable to ysus yet

[douellette88]

Re: LG 50" Plasma 50PS30-UB powers on, no picture, no sound

Also, try (with power disconnected) disconnect the ribbon cable from control board to Ysus (top left of control board) then power on TV. Do any leds fash on the control board?

Tried this and nothing changed, still steady green light

[douellette88]

Re: LG 50" Plasma 50PS30-UB powers on, no picture, no sound

Any other things I can try? And are any of you available to help out with this on a more live basis such as Facebook? I'm not sure if it's allowed but I would probably be willing to send a little money your way

[douellette88]

Re: LG 50" Plasma 50PS30-UB powers on, no picture, no sound

Bump.....anyone?

[niblettr]

Re: LG 50" Plasma 50PS30-UB powers on, no picture, no sound

Do you have access to an oscilloscope? If so, check for pretty waveform going from control board to Ysus board.

[niblettr]

Re: LG 50" Plasma 50PS30-UB powers on, no picture, no sound

Out of the 2 connectors on the top right of the control board. The one that goes to the power supply board (the grey cables I suspect) . What do the voltages read on each pin?