LG 50PS80 51" plasma - startup issue

[millermankjm]

Re: LG 50PS80 51" plasma - startup issue

Last 4 from Front... Note found that Q15 drain and source had about .3 ohms in both directions.. think its shorted. Q13 and Q14 show 8M ohms drain -, source + and open the other way with the probe leads.









Let me know what other measurements to make...

[tom66]

Re: LG 50PS80 51" plasma - startup issue

Shorted Q15 could do it! That looks to be the regulation transistor.

[millermankjm]

Re: LG 50PS80 51" plasma - startup issue

Will swap out and let you know how it goes. Thanks for all you help so far!

[millermankjm]

Re: LG 50PS80 51" plasma - startup issue

Found a good deal on the Z-sus board so picking that up to compare with mine. I found a link to a very similar problem here:

http://www.tv-forums.com/forum/TV_Eq...oting_P151178/

Seems Q13-15 and a few other parts are involved with a fix kit that is sold on eBay. Looks like a bear to disassemble, especially that sticky foam I had to peal away..

If mine doesnt test out, I'll fix for a spare later.. Here's hoping that the replacement is the fix. I'll test the VZbias first prior to hooking up the to the panel to make sure its in specs.

[millermankjm]

Re: LG 50PS80 51" plasma - startup issue

Soooooo... yes, it was the Z sustain board. Plugged the new one in without connecting it to the display and the Zbias measured correctly! Shut her down and waited a bit and inserted the flexible circuit connectors to the board and powered her up and it was nice and stable. Thank you so much for getting this newbie a working unit that I would have been pondering over for awhile if not for this forum and yourself! Let your professors know that you are doing a great job here support many people. You have a gift and using it like this is a wonderful thing... Let see, since last discussed, bought second hand Playstation 3 40G. Total investment.......$142 and our time... Watching first Bluray tonight after hooking back up the 5.1 system that I've had but not used in some time now.. Again, thanks!

[tom66]

Re: LG 50PS80 51" plasma - startup issue

Glad to hear it's fixed, thanks for the feedback too.