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...
millermankjm
Member
Last Activity: 06-28-2013, 11:45 AM
Joined: 06-18-2013
Location: Boston, MA
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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:
[url]http://www.tv-forums.com/forum/TV_Equipment_C4/TV_Repair_Forum_F3/LG_50_Plasma_(50PS60)_Troubleshooting_P151178/[/url]
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...Leave a comment:
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Re: LG 50PS80 51" plasma - startup issue
Will swap out and let you know how it goes. Thanks for all you help so far!Leave a comment:
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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.
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Let me know what other measurements to make...Re: LG 50PS80 51" plasma - startup issue
Last 4 from Front... Note found that Q15 drain and source had...Leave a comment:
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Re: LG 50PS80 51" plasma - startup issue
And the front....
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[ATTACH]66014[/ATTACH]Re: LG 50PS80 51" plasma - startup issue
And the front....
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[ATTACH]66008[/ATTACH]...Leave a comment:
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Re: LG 50PS80 51" plasma - startup issue
Here is the back...
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[ATTACH]66005[/ATTACH]Re: LG 50PS80 51" plasma - startup issue
Here is the back...
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[ATTACH]66001[/ATTACH]...Leave a comment:
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Re: LG 50PS80 51" plasma - startup issue
Since I dont have it plugged in... I'll pop it out and take some closeups as best I can.Leave a comment:
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Re: LG 50PS80 51" plasma - startup issue
These are the best I can do..
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I've had the TV on without the Z-sus connected and the image has not changed, audio is the same so all else seems to be stable. I did try the pic adjustments to brighten but as expected, no results which was expected.Re: LG 50PS80...Leave a comment:
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Re: LG 50PS80 51" plasma - startup issue
My Zsus pics..
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[ATTACH]65950[/ATTACH]Re: LG 50PS80 51" plasma - startup issue
My Zsus pics..
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[ATTACH]65950[/ATTACH]Re: LG 50PS80 51" plasma - startup issue
My Zsus pics..
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[ATTACH]65950[/ATTACH]...Leave a comment:
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Re: LG 50PS80 51" plasma - startup issue
Should have been resistor instead of transistor!Leave a comment:
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Re: LG 50PS80 51" plasma - startup issue
I adjusted the pot for Vzbias and it had no effect on the output. I carefully reviewed where the TP for that measurement was several time according to the doc.. Its a leg of a raised transistor. Attached are pics. I dont have the schematic so where to go now?
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[ATTACH]65940[/ATTACH]Re: LG 50PS80 51" plasma - startup issue
I adjusted the pot for Vzbias and it had no effect on the output. I carefully reviewed where the TP for that measurement was several time according...Leave a comment:
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Re: LG 50PS80 51" plasma - startup issue
Latest pics after Z-sus cable disconnected from power supply...
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[ATTACH]65938[/ATTACH]Re: LG 50PS80 51" plasma - startup issue
Latest pics after Z-sus cable disconnected from power supply...
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[ATTACH]65938[/ATTACH]...Leave a comment:
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Re: LG 50PS80 51" plasma - startup issue
I checked Vzbias at 193 which is definitely not 100! Pulled the cable from the PS to the Z-sus and powered it up. Came to life and stayed on with a decidedly dark screen which is so much better. The picture is yes dark but consistant.. like the brightness is way down. It does have a consistant red tint to it. Soooo, looking at the Z-sus board now for physical issues. What would be driving it to that level without me smelling something burning or toasting the display? I wont plug back in until I can understand how the voltage can get...Leave a comment:
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Re: LG 50PS80 51" plasma - startup issue
I check -Vy at -181 and VSC at 141 according to the label on the Y-Sus board during the 10 seconds it was on.Leave a comment:
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Re: LG 50PS80 51" plasma - startup issue
Here they are...
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Here they are...
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Re: LG 50PS80 51" plasma - startup issue
Tom, Thanks for your quick reply! I checked both Vs and Va and the were 195v and 65v according to the sticker at the top of the chassis. The picture just looks too bright and especially I can see some burning from the previous owner. Could the Y-Sus board be driving the display too hard or the signal from the control board causing the Y-Sus to drive hard?Leave a comment:
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Re: LG 50PS80 51" plasma - startup issue
These are the pics of the startup that I see..
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These are the pics of the startup that I see..
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[ATTACH]65927[/ATTACH]Re: LG 50PS80 51" plasma - startup issue
These are the pics of the startup that I see..
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...Leave a comment:
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LG 50PS80 51" plasma - startup issue
I picked up an LG 51" that a seller said had a white screen. When we turned on, it had the normal unconnected TV noise. Took home and it showed a good picture on HDMI and composite inputs. After attaching the stand and flipping it 180 end on end to place on storage cabinet to view, it did not stay on for more than 5 seconds first time powered up, 2nd stayed on for 7 seconds and third it stayed on coming up with the very bright image levels (faces white) and little blacks. Key here was that when the tv shutdown the first two times, it showed the correct image as it was powering off thus leading... -
Re: New Members - please post your introductions here
Hey there, I was looking for a place to land to get some answers and to give some as I have. Computers stuff is where I'm at but analog stuff mixed in is where I'm at now.. ie tempermental plasma that got me stumped! Hope I can benefit both ways!Leave a comment:
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