LG plasma logic board blink code

[Poor Flick]

I have a LG plasma model 60PA6500-UA made 2/12
I have looked at other threads and have came close to finding an answer but not quite. My logic board has a green LED labeled D101. When powered up it flashes short, short, long, short in lit duration. Is this a diagnostic code? If it is, what does it mean? Thanks!

[tom66]

Re: LG plasma logic board blink code

I don't know -- but you probably don't need it.
(As far as I know, no listing for these codes exists, unfortunately...)
On these panels it's a good idea to try without the top buffer installed. If you get a picture on the lower half you probably have a bad panel which is killing buffer boards.

[Poor Flick]

Re: LG plasma logic board blink code

I did try again with the 3 address buffers disconnected, same sequence. Are those the ones you suggested? Mine are along the bottom. Thanks!

[tom66]

Re: LG plasma logic board blink code

The Y-buffer runs along the left hand side of the TV when looking from the rear. You should avoid fiddling with the lower X-buffer board. If you have adjusted it make sure all ribbon cables are seated and the heatsink is secured. And NEVER disconnect any connector if power is still applied or shortly afterwards (as you can kill the panel easily.)

[Poor Flick]

Re: LG plasma logic board blink code

Thanks again Tom, I'll try that when I get home tonight. When I've removed and re connected I've been waiting about 10-15 minutes for power to dissipate, was that long enough? If my panel may be bad, is there a way I can tell for sure? Lastly if my baby is done, is there a more durable type tv to buy? example, LED,LCD? Thank You, Tom.

[tom66]

Re: LG plasma logic board blink code

10-15 minutes is more than sufficient.

Plasma is the most durable in terms of panel failure. LED/LCD is terrible for panel failure. (But every model gets bad apples. Samsung LED/LCD panels die frequently. LG panels are a lot more reliable.) Overall I'd say plasma is more reliable, and even if it fails, in most cases plasma is repairable, LED/LCD is expensive to repair and often difficult to troubleshoot.

The type of failure is a design flaw by LG where plastic clips on the side of the frame rub into the flex ribbons causing minor tears. These lead to short circuits which damages the Y-buffer board. (Replacing the board will lead to rapid failure again as the short is still present.)

[Poor Flick]

Re: LG plasma logic board blink code

Ok, I'll get a flashlight and a magnifying glass and do some inspecting, I appreciate your help!

[Poor Flick]

Re: LG plasma logic board blink code

I don't know -- but you probably don't need it.
(As far as I know, no listing for these codes exists, unfortunately...)
On these panels it's a good idea to try without the top buffer installed. If you get a picture on the lower half you probably have a bad panel which is killing buffer boards.

Tom66, I find it hard to give up without a fight. I want to attempt your previous advice one more time. I couldn't get my white, hard plastic multi pin connectors to separate from the Y sustain board. The connectors are very tight and I don't want to break anything. What trick do you use? Is my objective to remove the top buffer completely from panel ribbons and the Y sus and try powering up? Please type slowly, as I am definitely a slow learner!

[Poor Flick]

Re: LG plasma logic board blink code

What would happen if I just disconnected the Y buffer ribbons from the panel? Sorry, I posted the sus pic sideways

[tom66]

Re: LG plasma logic board blink code

You do have to unscrew the board first.
Undoing only the orange ribbons unfortunately would not help.

[Poor Flick]

Re: LG plasma logic board blink code

I had the screws out at the time I was trying to take it out, do the white connectors have a release/latch? Gentle prying with a screwdriver? Thanks Tom

[MagicSmoke]

Re: LG plasma logic board blink code

No prying on ribbon connectors. See the black part of the connector on the opposite side of each ribbon. Lift with fingernail and it will release the ribbon.

Be gentle removing/installing the ribbons as they can be damaged easily. Some ribbons have tiny holes in them you have to lift up to remove from connector (the X buffer ribbons in my tv has these) the Y buffer ribbons did not.

[Poor Flick]

Re: LG plasma logic board blink code

Thanks MagicSmoke, I'm having trouble with the 3 white, hard plastic Ysus to buffer connectors, very tight, any ideas? Very cool member name!

[MagicSmoke]

Re: LG plasma logic board blink code

Those are tight fitting, you just have to wiggle and pull gently away from each other. Just when you think it's going to break they will release.

Sometimes a tiny screwdriver will help to separate them, pull in a manner to start separation from top to bottom or bottom to top,then pull straight apart.

Once you have the buffers removed from X & Y main boards you can power up the set w/ X & Y main boards connected to PSU to check the various voltages. VA,VS,VE and Vscan or whatever they are named on the panel sticker.

Also as Tom has indicated check very closely w/ a magnifying glass the ribbons for any signs of rubbing or tears if any of the tiny traces are separated or shorted then repair is virtually impossible.

[Poor Flick]

Re: LG plasma logic board blink code

Ok MagicSmoke, thank you! This may be my last chance to find something repairable but it's likely a bad panel, worth a shot. I'm a glass half full guy but sometimes it's half full of bad stuff!

[chood2]

Re: LG plasma logic board blink code

Did anyone find a solution to this? I have the same issue.. Same tv...

[tw2005]

Re: LG plasma logic board blink code

Did anyone find a solution to this? I have the same issue.. Same tv...

Solution to what? I don't even a mention a mention of symptoms other than a CTRL BD with a blinking LED which for an LG is likely very normal.

I don't know this model but first thing I'd try would be to isolate the main and jumper the CRTL BD to activate the test patterns.

If that yielded nothing, I 'd confirm the correct voltages on the ysus, go from there.
I had a blinking CTRL BD last night, volatges normal, black screen. Ysus was faulty but not shorted

[chood2]

Re: LG plasma logic board blink code

I have a faulty, but not shorted YSUS. Caps look good... Not bulging... Buzzing however is quite present.

I don't see where it shows what voltages VSETUP and VY, etc should be? I have oscilloscopes, etc.

[Poor Flick]

Re: LG plasma logic board blink code

Chood2, I got your email but I thought I’d post the reply here, maybe it will help others also.
I never found an answer to my flash code. What did happen is that I replaced the power supply board and got my panel to come mostly on with no sound. Replacing the logic board got my sound on. In the process I didn’t see a defect in the end of a ribbon connector, causing the blank spot in my panel. I continued troubleshooting by pulling off the skinny long metal cover on top of the ICs along the bottom of the panel thinking I would test for power on the boards. What I didn’t know was the metal cover is a heat sink and when I powered it up to do voltage checks, the ICs overheated and my panel was then junk. At the time my TV had a few weeks of warranty left and after a honest talk with a repair shop, I got a new panel installed for almost free.
Closer inspection of things showed a tiny burnt hole in a chip on the logic board, I never could figure out why my power supply was bad.
This was my first try at fixing a TV.

[tw2005]

Re: LG plasma logic board blink code

Chood2, I got your email but I thought I'd post the reply here, maybe it will help others also.
I never found an answer to my flash code. What did happen is that I replaced the power supply board and got my panel to come mostly on with no sound. Replacing the logic board got my sound on. In the process I didn't see a defect in the end of a ribbon connector, causing the blank spot in my panel. I continued troubleshooting by pulling off the skinny long metal cover on top of the ICs along the bottom of the panel thinking I would test for power on the boards. What I didn't know was the metal cover is a heat sink and when I powered it up to do voltage checks, the ICs overheated and my panel was then junk. At the time my TV had a few weeks of warranty left and after a honest talk with a repair shop, I got a new panel installed for almost free.
Closer inspection of things showed a tiny burnt hole in a chip on the logic board, I never could figure out why my power supply was bad.
This was my first try at fixing a TV.

OMG, as soon as I read you removed the bottom heatsink I stopped. I feel your pain. Did that some years ago myself on a Samsung destroying a perfectly good panel.