LG Plasma 60pk950-UA no picture or sound

[clubberlange]

Re: LG Plasma 60pk950-UA no picture or sound

I made a mistake in what I said above. The YES/NO are the wrong way around.



Seems like the case "YES" applies to you. So try with only one buffer at a time. The Y-sustain doesn't need replacing.

These LG Y-buffers seem to be a common fault, seen several with this failure recently.

When you say isolate the buffers, do you mean remove the p106,p206 connector that jumps from one board to the other?

[tom66]

Re: LG Plasma 60pk950-UA no picture or sound

I made a mistake in what I said above. The YES/NO are the wrong way around.

Voltages good when buffers isolated?

NO:- Repair/Replace Y-sustain. Limited repair information available, no schematics, so replacement is advised, although some basic tracing can be done.

YES:- Replace Y-buffer(s). (Generally considered non-serviceable due to construction.) Locate which board is causing the fault. To do this try plugging in only one board at a time. There is a YB TOP and YB BOTTOM. Remember to isolate the connection between the two at all times. Check voltages. If the isolation of one board causes the voltages to come up, replace that board. (The panel may or may not work with the board removed. It could display half an image, no image, or just strange patterns.)

Seems like the case "YES" applies to you. So try with only one buffer at a time. The Y-sustain doesn't need replacing.

These LG Y-buffers seem to be a common fault, seen several with this failure recently.

[clubberlange]

Re: LG Plasma 60pk950-UA no picture or sound

OK, we're close. It is either the Y-buffers or Y-sustain.

At this point please undo both connectors P104 and P105 on the Y-sustain board (refer to document for locations.) These connect to the buffer boards. Leave all screws in place. Then power on set and check these voltages. Are they as they should be?

YES:- Repair/Replace Y-sustain. Limited repair information available, no schematics, so replacement is advised, although some basic tracing can be done.

NO:- Replace Y-buffer(s). (Generally considered non-serviceable due to construction.) Locate which board is causing the fault. To do this try plugging in only one board at a time. There is a YB TOP and YB BOTTOM. Remember to isolate the connection between the two at all times. Check voltages. If the isolation of one board causes the voltages to come up, replace that board. (The panel may or may not work with the board removed. It could display half an image, no image, or just strange patterns.)

Sorry, kinda jumped the gun on that one. If I unplug p104,p105 the voltages are good. ShopJimmy has the Y-SUS and buffers in stock. Would you recommend replacing the buffers too?

[tom66]

Re: LG Plasma 60pk950-UA no picture or sound

At the moment, as I said, the power board is not under consideration because the voltages it is producing are all nominal. If this was not the case then I would suggest checking the power board, but it's working fine.

Be very careful when plugging in Y-sustain again. Wait a few minutes for Vs to drop below 50V before connecting it.

[clubberlange]

Re: LG Plasma 60pk950-UA no picture or sound

-Vy jumps between 10v-40v
Vsc jumps between 10v-30v

If I unplug p113,p114 and take the y-sus out of the equation my voltages on f801,501,301 are good. When the Y-SUS is connected my incoming voltage to the power supply drops to 60v.

[tom66]

Re: LG Plasma 60pk950-UA no picture or sound

OK, we're close. It is either the Y-buffers or Y-sustain.

At this point please undo both connectors P104 and P105 on the Y-sustain board (refer to document for locations.) These connect to the buffer boards. Leave all screws in place. Then power on set and check these voltages. Are they as they should be?

NO:- Repair/Replace Y-sustain. Limited repair information available, no schematics, so replacement is advised, although some basic tracing can be done.

YES:- Replace Y-buffer(s). (Generally considered non-serviceable due to construction.) Locate which board is causing the fault. To do this try plugging in only one board at a time. There is a YB TOP and YB BOTTOM. Remember to isolate the connection between the two at all times. Check voltages. If the isolation of one board causes the voltages to come up, replace that board. (The panel may or may not work with the board removed. It could display half an image, no image, or just strange patterns.)

[clubberlange]

Re: LG Plasma 60pk950-UA no picture or sound

For now, since the Vs and other voltages are present, the power board is not currently suspect. Please check the -Vy and Vsc first.

-Vy jumps between 10v-40v
Vsc jumps between 10v-30v

[tom66]

Re: LG Plasma 60pk950-UA no picture or sound

For now, since the Vs and other voltages are present, the power board is not currently suspect. Please check the -Vy and Vsc first.

[clubberlange]

Re: LG Plasma 60pk950-UA no picture or sound

OK, that's good.

See attachment.

With TV OFF and UNPLUGGED:
- Disconnect the blue highlighted cable, by pressing each clip gently and pulling backwards with minimal force.
- Place a wire link between the two holes marked in red.

Then plug TV in and turn on if it is in standby.

You may or may not see test patterns, but if you do, it indicates the main board is bad (not this board... the board with HDMI etc.)

I was doing some more research on here and I found a block diagram for the 60pk750 with the 60r1 panel. Since it has all the same boards and panel as mine except for the main board am I to assume the voltages will be the same? If so I took some measurements on the power supply. f801,f501, and f301 only read half of what they should according to the diagram.

VS=201.6
VA=59.6V
M5V=5.15V
17V=17.17V
STBY=5.15V

F801
stby 0v
run 174.7v

F501
stby 0v
run 174.7v

F301
stby73.8v
run 174.3v

[tom66]

Re: LG Plasma 60pk950-UA no picture or sound

Luktech is probably not correct. It is most likely not involving the main board at the moment. More testing is necessary.

At this point, I am going to assume you have a PDP60R1 panel, but please confirm this by looking at the sticker with voltages on it, it will be marked something like "LG Electronics PDP60R1##### Made in KOREA 2010.09.03".

Please refer here:
http://tgohome.com/ServiceManuals/?d...h=Submit+Query

On the 5th page it instructs you on how to test the Vsc and -Vy voltages. Please do so and compare to the label on the plasma panel.

[clubberlange]

Re: LG Plasma 60pk950-UA no picture or sound

since no picture and no sound. The mainboard is bad

This is the only board I am having trouble finding. Everyone is out of stock.
Is there someone on here that can repair this board?

[luktech]

Re: LG Plasma 60pk950-UA no picture or sound

since no picture and no sound. The mainboard is bad

[clubberlange]

Re: LG Plasma 60pk950-UA no picture or sound

OK, that's good.

See attachment.

With TV OFF and UNPLUGGED:
- Disconnect the blue highlighted cable, by pressing each clip gently and pulling backwards with minimal force.
- Place a wire link between the two holes marked in red.

Then plug TV in and turn on if it is in standby.

You may or may not see test patterns, but if you do, it indicates the main board is bad (not this board... the board with HDMI etc.)

Still nothing

[tom66]

Re: LG Plasma 60pk950-UA no picture or sound

OK, that's good.

See attachment.

With TV OFF and UNPLUGGED:
- Disconnect the blue highlighted cable, by pressing each clip gently and pulling backwards with minimal force.
- Place a wire link between the two holes marked in red.

Then plug TV in and turn on if it is in standby.

You may or may not see test patterns, but if you do, it indicates the main board is bad (not this board... the board with HDMI etc.)

[clubberlange]

Re: LG Plasma 60pk950-UA no picture or sound

ok, the top right connector on this board has two pins at the bottom marked vs
https://www.badcaps.net/forum/attach...2&d=1386049781

with the red probe of the meter touching vs, black probe on chassis and meter on highest dc range (or autoranging) measure the voltage on the bottom most pin with the set in the fault condition. What do you see?

The ratings for vs, va and other voltages are printed on the panel sticker which has lg electronics logo and pdp60####### markings.

201.6v

[tom66]

Re: LG Plasma 60pk950-UA no picture or sound

OK, the top right connector on this board has two pins at the bottom marked VS
https://www.badcaps.net/forum/attach...2&d=1386049781

With the red probe of the meter touching VS, black probe on chassis and meter on highest DC range (or autoranging) measure the voltage on the bottom most pin with the set in the fault condition. What do you see?

The ratings for Vs, Va and other voltages are printed on the Panel Sticker which has LG Electronics logo and PDP60####### markings.

[clubberlange]

Re: LG Plasma 60pk950-UA no picture or sound

OK, at this point, you'll need a digital multimeter. Do you have one, or can you borrow one? An analog multimeter will not suffice unfortunately.

Yes I have one.

[tom66]

Re: LG Plasma 60pk950-UA no picture or sound

OK, at this point, you'll need a digital multimeter. Do you have one, or can you borrow one? An analog multimeter will not suffice unfortunately.

[clubberlange]

Re: LG Plasma 60pk950-UA no picture or sound

OK, on this circuit board, there is a light (logic board)
https://www.badcaps.net/forum/attach...4&d=1386049781

Do you see the light glow or flash when the set is powered up?

Yes. It flashes once, then a real quick flash. A few second pause, then repeats.

[tom66]

Re: LG Plasma 60pk950-UA no picture or sound

OK, on this circuit board, there is a light (logic board)
https://www.badcaps.net/forum/attach...4&d=1386049781

Do you see the light glow or flash when the set is powered up?