zenith Z50P3 PLASMA TV screen issues pink and purple grainy no image

[shelby5041]

hi

i have 2 of these exact same tvs zenith z50p3 and both are doing the same thing..i got them from 2 diff sellers and both power on but the display is messed up..........the screen is not cracked....sound works...and powers on fine but see photos........the display is pink and purple and black grainy and messed up bad and it the configuration of weird patterns and colors continues to change when tv is on....both tvs are in great cosmetic condition and would love to repair them if repairable........

i have had these for a few yrs and couple yrs ago whil troubleshooting i bought new y-board..new z- board and replaced the buffer boards and did not fix the issue..so not im getting back to them to see if i can bring them back to life or throw them in trash

note: the photos with black horizontal stripes spaced apart evenly is just a camera issue they are not actually on the display its just how the camera took the pics

any help would be appreciated

[shelby5041]

Re: zenith Z50P3 PLASMA TV screen issues pink and purple grainy no image

from my research it seems that everything points to either y board or z board but like i said i replaced them with "working" used ones on ebay and it didnt fix the problem.....as we know the used boards also could have been bad...so not sure now....but like i said i would like to repair this

the y boards are almost impossible to find and are real expensive so that tells me that its a very very common problem

supply and demand.......and since the tv is so old and the part is still expensive means it is extrememly rare...........a board on a tv this old should be next to nothing since its outdated....

[freakaftr8]

Re: zenith Z50P3 PLASMA TV screen issues pink and purple grainy no image

Shorted mosfets on y board. Check all of them. Also check all voltages from the power supply. Do they match the panel label?

[shelby5041]

Re: zenith Z50P3 PLASMA TV screen issues pink and purple grainy no image

ps voltages good....could this be panel or z issue or do u think y issue?

[sugar_ray]

Re: zenith Z50P3 PLASMA TV screen issues pink and purple grainy no image

From my plasma experience fixed lines (similar to the ones in your photos) have almost always meant a bad panel for me!! Lots of people disregard the need to replace the buffer boards with the sustain boards in question. If a bad buffer was the reason the sustain board failed then marrying the bad buffer to a good replacement sustain will only cause the good board to fail pretty much right away.

Buffers can only be checked with an oscilloscope to measure variable voltage.

[shelby5041]

Re: zenith Z50P3 PLASMA TV screen issues pink and purple grainy no image

hi there are no fixed lines............the horizontal lines in photo are from camera


not on screen

[shelby5041]

Re: zenith Z50P3 PLASMA TV screen issues pink and purple grainy no image

the screen is random and changes colors and patterns continuously see photos.........the blackish horizintal lines are from camera not actually on display of tv

[shelby5041]

Re: zenith Z50P3 PLASMA TV screen issues pink and purple grainy no image

i tested the buffers a few yrs ago and they tested shorted so i bought new ones from shop jimmy.......along with another y board

original symptoms were tv would power on and then power off....when i replaced the buffer and y boards tv powered on but pink purple distorted screen like shown

this has been a project i worked on years ago and could not fix im trying to get back to it before i toss tv in trash

so my memory may not be greatest since it was about 3 yrs ago that i was deep in it...so i cant remember everything

all i know is i want to fix it now if at all possible

[shelby5041]

Re: zenith Z50P3 PLASMA TV screen issues pink and purple grainy no image

the power supply voltages are fine so now its either a panel issue or z or y board issue

even though i did replace z and y ....many boards on ebay are sold as working and they dont work.........very normal since they cant test them they just assume they work....

[tw2005]

Re: zenith Z50P3 PLASMA TV screen issues pink and purple grainy no image

All I could suggest would be to isolate completely 1 buffer board at a time and see if that gives have a good picture. When isolating, disconnect from the ySUS and if there is a interconnecting cable that links the upper board to the lower disconnect that too.

[shelby5041]

Re: zenith Z50P3 PLASMA TV screen issues pink and purple grainy no image

thank you ...

according to shop jimmy the symptoms all point to the z board

they said buffer boards typically cause issues horizontally since each board covers a % of screen depending on how many buffers there are

[tw2005]

Re: zenith Z50P3 PLASMA TV screen issues pink and purple grainy no image

thank you ...

according to shop jimmy the symptoms all point to the z board

they said buffer boards typically cause issues horizontally since each board covers a % of screen depending on how many buffers there are

Not always. I've seen shorted buffers cause a messed up screen and you described irregular patterns moving about the screen which can be the no signal bobbing randomly about the display which on LG stuff it does.

[shelby5041]

Re: zenith Z50P3 PLASMA TV screen issues pink and purple grainy no image

thanks....i originally did change both buffers years ago and did not fix issue..i also replaced y board and z board did not fix issue...but remmeber one thing im buying used boards on ebay so there is no guarantee the boards are actually good.....lots of people sell boards on ebay as working and they dont know

so its hard to isolate....

i was going to throw them in the trash but decided to give it another shot.....


so i really need someone who has a lot of knowledge on plasmas as not many people do since they are way way more complicated than lcd tvs....

i was just trying to see if i could find someone that would say definitely what board would fix the issue and i would buy that board and try one more time otherwise they would be going to dumposter


thanks

[shelby5041]

Re: zenith Z50P3 PLASMA TV screen issues pink and purple grainy no image

the buffers would affect a section of the screen not the entire screen and the section would run horizintally............according to shop jimmy you tube video basic plasma troubleshooting tips

[shelby5041]

Re: zenith Z50P3 PLASMA TV screen issues pink and purple grainy no image

but i guess if all buffers were bad it would affect whole screen so i dont know......

[shelby5041]

Re: zenith Z50P3 PLASMA TV screen issues pink and purple grainy no image

i have over 300.00 in parts already and this tv is worth probably only 100-150.00 in working condition lol............so at this point not sure i even want to continue trying to fix it....

[shelby5041]

Re: zenith Z50P3 PLASMA TV screen issues pink and purple grainy no image

look at this old link looks similar to mine and 2 people say z board

http://www.avsforum.com/forum/167-pl...re-thread.html

[tw2005]

Re: zenith Z50P3 PLASMA TV screen issues pink and purple grainy no image

two things which catches my attention.

1. on TV 1 (pics 1 & 2) how bright and white that centre band is, I'm thinking it's pretty bright for a dead Zsus

2. TV 2 there are in fact horizontal lines on that one both at the top and centre

You have 2 sets of buffers, if it's only one board dragging the ysus down then you may get lucky and get half a good display isolating and swapping the buffer boards.

Another thing I'm thuiking iss if the zsus is dead , then if that board was isolated then theorectically you should end up with the same display no change.

I guess you've tried swapping the zsus across from the other TV? any change?

[shelby5041]

Re: zenith Z50P3 PLASMA TV screen issues pink and purple grainy no image

the photos i posted were from the same unit....i do have 2 of these tvs exact same model doing same thing...

..i just got home from work and disconnected the z board ....

when i power the tv it powers on fine but the screen is now totally black......and almsot no static noise....very very very slight..almost cant hear it.

with the z board in ...the screen is like you see it in my photos and the screen flickers real bad and makes loud static noise and changes patterns and colors pink white red blueish purple continuously but there is no horizontal permanent defects areas on screen...im not a tv tech but i really dont think its bad buffers ..the ones i bought i got from shop jimmy....the other boards on ebay

i really would like to fix these two they are in mint condition cosmetically...i know i did swapping..boards and couldnt get 1 to work at all...3 yrs ago...i bought 2 used "working" y boards and 1 used "working" z baord and 2 new buffers and 1 new logic.....nothing fixed the issue....just all of that i paid well over 300.00 for...its sad

[shelby5041]

Re: zenith Z50P3 PLASMA TV screen issues pink and purple grainy no image

and like i said those pics i posted are from the same tv......i was hitting menu and input buttons and the screen i think went from darker colors to bright pink white...