Joined: 14 Dec 2017
Location: Sheffield, UK
|Posted: Thu Dec 14, 2017 8:24 am Post subject: LG Plasma - 50PB690V - ZSUS Flashing Screen, No Booting!
|Replaced Zsus beginning of year from ebay as most transistors were short stopping tv powering up.
Then gave up till now:
Now screen flashes on off continually and ZSUS ticks in correlation. Looking like replacement maybe faulty or could something else cause it to shut down.
If I remove both tabs from ZSUS to screen but keep all other connectors to ZSUS on then TV boots properly but screen very dark without ZSUS output, no ticking from ZSUS. So it only shuts down when under load from screen.
What voltages should I have on ZSUS output connectors to the screen please?
When tabs connected it is off scale on multimeter (600v scale) but when unplugged it bounces around say 300, 400, 550 etc.
If it is ZSUS then how to fault find, I already looked for shorts. No transistors shorted or caps and its happy to stay on when not connected to screen and makes similiar quiet buzzing as YSUS which I think is normal?
All voltages on PSU and Y/Z SUS boards normal when screen not connected to ZSUS.
Please advise what I should test or how to test the various transistors on the ZSUS?
Control Board LED flashes normally when booting without screen attached to ZSUS and can run the test patterns.
Attached some pics, can do more if necessary.
ZSUS Board - EBR77256501.
Well I cant figure out how to attach pics but I attached some of the ZSUS board at Badcaps:
Had no responses there so thought I'd see if more people here know about Plasmas.
Many thanks - Simon.[/img]