lg 50pa4500 picture very bad

[tonytiger]

Re: lg 50pa4500 picture very bad

i did the self test and yes the color partern was there but still colors was like the screen right now very bad....but red was red,ect....so the selt test at my advice was ok.

[dskall]

Re: lg 50pa4500 picture very bad

Maybe a picture of the screen with test pattern.

[ReeceyBurger123]

Re: lg 50pa4500 picture very bad

Normally Red is only bad if the Zsus erc ramp is not working or Ve is bad, have you checked Vsc on the Ysus ?

[tonytiger]

Re: lg 50pa4500 picture very bad

hi again,i did some other test as you asked me like vsc on ysus, if my test was ok i did black probe on chassi ground and red at the + of vsc gave me a reading of jumping from 78v to 82v at vsc - jumping -86v to -89v............vy + jumping 120v to 124v and - jumping -86v to -89v......and im trying to put a small video here so you could see test partern since it is doing a partern on red,green,blue,white and some others black bars going on the screen and re-starting partern....so photos would be to hard taking them at the right time

[Davi.p]

Re: lg 50pa4500 picture very bad

Is strange that autotest lasts so few, i saw few colors, are you sure is the entire test? I saw that test only one time, if i remember the test is positive! (so bad mainboard?)

[Hamie]

Re: lg 50pa4500 picture very bad

hi again,i did some other test as you asked me like vsc on ysus, if my test was ok i did black probe on chassi ground and red at the + of vsc gave me a reading of jumping from 78v to 82v at vsc - jumping -86v to -89v............vy + jumping 120v to 124v and - jumping -86v to -89v......and im trying to put a small video here so you could see test partern since it is doing a partern on red,green,blue,white and some others black bars going on the screen and re-starting partern....so photos would be to hard taking them at the right time

You need to measure vsc and -vy across the test points.

Ie:

black probe to -

Red probe to +

[tonytiger]

Re: lg 50pa4500 picture very bad

hi and sorry for delay,well the test is that long and it will re-start to the red,ect....as for the measurement that what i tought i was maybe doing it wrong so here is the resulte:

vsc=151.3v
-vy=190.5v

and thanks for helping me.

[dick_barton]

Re: lg 50pa4500 picture very bad

Those two voltages appear to match what is given in other threads
Vsc = 150V
Vy = -190V

Have you checked.
Vs = 205V
Va = 55V

[tonytiger]

Re: lg 50pa4500 picture very bad

yes the vs and va voltage also where check and good ......very stange still looking and testing every connection to see if there is a defference in image,but no luck for now...

[Davi.p]

Re: lg 50pa4500 picture very bad

waiting for more experienced... why you don't tell the mainboard code?

[tonytiger]

Re: lg 50pa4500 picture very bad

sorry davi.p did not quite understand you question about mainboard code...is there something or someway i can test more the mainboard.to rule this one out....have no much more ideals on what to do or test...thank you.

[Davi.p]

Re: lg 50pa4500 picture very bad

sorry for my english, i mean the model number of mainboard, or, better, shopjimmy pictures of back and front, is it Eax64696604? this?:
http://mgelectronicsrepairservice.co...BT62143602.jpg

[tonytiger]

Re: lg 50pa4500 picture very bad

not your english,just me that missed giving that number.here it is :eax64696607(1.0)pa/pk/pu/pd/pb23a

photo from shopjimmy but if you need mine let me know.

thank you very much for help me.

[Davi.p]

Re: lg 50pa4500 picture very bad

My thought was incorrect.. i don't know where to point at...

[Hamie]

Re: lg 50pa4500 picture very bad

So what's your z-bias voltage?

Located on z-sus. Might be labelled VZB

[tonytiger]

Re: lg 50pa4500 picture very bad

this is the board that i replace and i do have 129.7v on vzb.