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

[tw2005]

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

i do believe i have 5v coming from ps but i will double check that when i get time....i did check some pins today and i do remember seeing 5v from ps

but for sure no 5v from y to buffer and no 5v to z whcih on my tv comes from y

all fuses on y are good...i checked the 2 large fuses and the small surface mount fuses 4 of them...all good

one question though...is the 180v actual vs within tolerance of 193v vs spec

thats over 5% difference is this ok or would create a noticeable problem?

Vs should be adjusted to spec but maybe someone has already played with this and dropped it to get rid of maldischarge. I think the LGs tend to suffer as they get on get red and green sparkles. the 50PX5D I've seen did and dropping it can help a little. 180V though would not stop a picture though.

[shelby5041]

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

thanks.....thats all i wanted to know..was if 180v would be ok.....but yes it seems the ps is working fine....i really hope the y board i get fixes the problem i would be so happy and relieved

this tv has really cost me a lot of money in trial and error ...i know more now than i used to

i used to just swap boards now im trying to learn to test and rule things out and actually troubleshoot

i really wish i could learn to component troubleshoot...

i appreciate your help

i basically tinker with stuff nothing in particualr but recently tvs and laptops i have been tinkering with and decent success

[tw2005]

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

thanks.....thats all i wanted to know..was if 180v would be ok.....but yes it seems the ps is working fine....i really hope the y board i get fixes the problem i would be so happy and relieved

this tv has really cost me a lot of money in trial and error ...i know more now than i used to

i used to just swap boards now im trying to learn to test and rule things out and actually troubleshoot

i really wish i could learn to component troubleshoot...

i appreciate your help

i basically tinker with stuff nothing in particualr but recently tvs and laptops i have been tinkering with and decent success

Why not find the 5v rail on the ysus and check it's resistance isolated? I'm interested because you said it's missing 5v, to find the source of the loss would be cool. I like evidence, sure you've odered another ysus but would it not be good to confirm where and maybe why?

[shelby5041]

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

im sorry im not really trained in electronics and the terms i odnt know

what do you mean 5v rail and check for resistance

if you tell me what to do i can do it

thanks

[tw2005]

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

im sorry im not really trained in electronics and the terms i odnt know

what do you mean 5v rail and check for resistance

if you tell me what to do i can do it

thanks

well you found the point on the ysus that is suppose to have 5v. You found 0v.

with it off, remove any power cable connected to the ysus which has 5v marked next to a pin (includes the lead going to the zsus), then set meter to resistance,probe the 5v pin and other to earth point on the board and see what resistance is ther and then do the same for the Zsus.

If no 5v, i'm assuming dead short. So , where is the dead short ysus, zsus or is there no 5v out from psu.

You could always post up some clear photos of the boards so we can see what it is you see.

[shelby5041]

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

thanks ill try when i can....at work now

[shelby5041]

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

frustrating...replaced y board again.....absolutely no change......thats 3 "good" y boards no change...2 z boards no change

can anyone please help me...

[shelby5041]

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

this is what is confusing me bad.....when i have all boards plugged in and pwr tv on the screen is bright pink with white........if i unplug z display goes 100% black.......if i plug z back in and disconnect power to y buffers screen no change.....with or without y buffers plugged in screen has no change at all....i did this with 1 and 2 buffers plugged in and no change.....and yhis is exact same with all 3 y boards i bought

[shelby5041]

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

for some reason again im not seeing 5v to buffers and i have 5v coming from ps....actually 4.8v..r...unless im testing wrong.....5v pin and screw ground....i do have 4.8v going to z board......is this not enough v....should it be over 5v

[shelby5041]

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

hi i have a question maybe im testing the 5v wrong going to y buffers....how can replaced y boards all produce no 5v??

here is a photo of the cable going to buffer........there are 12 noted locations but only 11 pins ....how would i test for 5v and what would i use for ground

i tested the top 5 pins and used a screw for ground and got 0v

so im thinking im not doing something right

i have replaced 3 y boards....1 z board....2 buffers....and 1 logic board and the display looks the same all pink and white

[shelby5041]

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

correction there are 11 noted locations and 12 pins on the cable...can anyone tell me which pin would be the 5v pin and what to use as ground?

[shelby5041]

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

and what is earth point on board???

[tw2005]

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

hi i have a question maybe im testing the 5v wrong going to y buffers....how can replaced y boards all produce no 5v??

here is a photo of the cable going to buffer........there are 12 noted locations but only 11 pins ....how would i test for 5v and what would i use for ground

i tested the top 5 pins and used a screw for ground and got 0v

so im thinking im not doing something right

i have replaced 3 y boards....1 z board....2 buffers....and 1 logic board and the display looks the same all pink and white

I've marked the photo, after you test for 5V there, turn it off and then check the resistance between the same to see if there is a short

[shelby5041]

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

thank you i will check when i get home im at work till 730a........why are there not the same # pins as noted locations??

[tw2005]

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

thank you i will check when i get home im at work till 730a........why are there not the same # pins as noted locations??

no idea, maybe the last 2 are the same , gnd. I guess you don't know the board numbers so I can actually check SJ and see if they have a bottom view?

[tw2005]

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

looking at the tracks, I'm thinking.

1.GND
2. 5V
3. 5V
4. GND
5. YNSC(GND)
6. OC1
7. OC2
8. DATA
9. STB
10. GND
11. CLK
12. GND

[shelby5041]

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

thanks and b y the way the thing that really is hard to understand is why is it that when i disconnect power to z board the display goes back but when i plug z back in and disconnect power cable from y to buffers the screen does not change at all.......this is what is really confusing me....if the buffers and y are good then disconnecting them should in theory cause a change in the display correct?

[tw2005]

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

thanks and b y the way the thing that really is hard to understand is why is it that when i disconnect power to z board the display goes back but when i plug z back in and disconnect power cable from y to buffers the screen does not change at all.......this is what is really confusing me....if the buffers and y are good then disconnecting them should in theory cause a change in the display correct?

True, Well, I've had a feeling for a while it may end up being bad buffers , it's still a hunce but you have to prove what's what. You had no joy swapping them around, i was hopeful but no joy there but it's possible they're all bad.

When you get a chance try a continuity test between the output pins for the ribbons and the gnd screws. slide the probe slowly along the face of the ribbon connectors and watch what happens.

[shelby5041]

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

well yes originally 3 yrs ago the top y buffer on both tvs tested short per coppell tv repair site

i then bought 2 new top y buffers from shop jimmy and it did not fix problem....right now i have 2 replaqcement top y and 2 original bottom y

since then i have bought 3 y boards....and no change

[shelby5041]

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

ill have to resarch how to test for short on them i forgot