Re: LG 60PK750 Plasma loud buzzing blown panel?

I gave up on finding this fault (no picture, loud buzzing). Stripped the unit of its boards and tossed the panel.

For the record i couldn’t find any shorts in the YSUS and all voltages from PSU were normal and it wasn’t shutting down into protection. There was just a loud buzzing even when the Z and Y sustain was disconnected from the buffers (so not a panel issue). The loud buzzing went away when disconnecting signal cable between control board and YSUS, so assumed there was a fault in either of those. Couldn’t...

Re: LG 60PK750 Plasma loud buzzing blown panel?

I was wrong about disconnecting the YSUS makes the buzzing go away. Only by disconnecting Y and Z-sustain does the buzzing go away. As this video demonstrates.

[url]https://1drv.ms/v/s!At2_QJcZ3njMjiDSnw3FtlNklpwb[/url]Re: LG 60PK750 Plasma loud buzzing b...tlNklpwb[/url]

Re: LG 60PK750 Plasma loud buzzing blown panel?



Thanks for your post Unspun01.

I was thinking a panel issues because I could not localize the source of the buzzing. However, upon a quick check disconnecting YSUS from top and bottom Y buffers the buzz remained. Only with the YSUS d/c the buzz goes away. Protection isnt kicking in as the unit isnt turning itself off.

I will pull YSUS and check for shorts, cold solder joints etc., when I get home tonight....

Guys and gals,

basically I'd like to know if it's possible to electrically kill your plasma panel removing internal cabling with it still connected to mains? It's a PDP3R10000 panel btw.

BACKGROUND

This unit was working except for the HDMI ports. I confirmed again via disconnecting LVDS and jumpering test points on Control board - test image displayed fine.

Upon starting to disconnect the main board in an attempt to reflow the BGA chip, I disconnected the cable coming for the PSU board to the mainboard as shown in the pic. To my surprise...

Re: lg 60pz550 black screen, no power, etc

Actually, it's a different model. Sorry was on the train. I will start a new thread

Re: lg 60pz550 black screen, no power, etc

I have the same model and had to replace 4 Fairchild IGBTs.

Now the unit turns on and stays on but no picture.

Using a block diagram schematic ([url]http://www.toms-service-manuals.com/?do=search&mfg=LG-Zenith&modelsrch=60pk540&typekey=0&Search=Submit[/url]), i disconnected LVDS and shorted control board test pads.

To my joy a clear test pattern emerged! It’s here i noticed the control board led flashing: two long followed by two short blinks. The schematic mentioned if the...