Vizio P50 HDTV20A

[gideon277]

Okay this is a 50" Plasma Television. The TV powers on I have sound on all inputs. The Picture though is terrible and transitionally fades into existence only after considerable warm up. The picture when it finally comes up ends up patchy with a fuzzy appearance and sometimes patches are missing other times they are not. The picture is always darker than it should be.

[johnboy1313]

Re: Vizio P50 HDTV20A

Pictures?

[gideon277]

Re: Vizio P50 HDTV20A

This is a pretty typical state for the t.v to be in. Caps look okay.

[PlasmaRon]

Re: Vizio P50 HDTV20A

The caps on the PS look ok? I think I've yet to see one of these P50 sets that doesn't have some puffed up caps on the power supply. I'd still start out by checking the voltages to the panel.

[patrax]

Re: Vizio P50 HDTV20A

Definitely looks like a Psu cap to me . Even if the look good my bet is there is a bad one on the board. I have repaired two of this exact model and both had a cap that looked fine but upon further testing/replacing it was a Psu cap. Fluctuating voltage causes this condition because of a bad capacitor.

[mmartell]

Re: Vizio P50 HDTV20A

Is it my eyes or does the menu look ok ?

[tw2005]

Re: Vizio P50 HDTV20A

Looks like failed ZSUS assuming it's LG based panel or xmain if samsung but I'm expecting this is LG.

[gideon277]

Re: Vizio P50 HDTV20A

okay the tv is in fact Samsung based. No caps appear to be bad as I can tell here are some more photos.

[gideon277]

Re: Vizio P50 HDTV20A

I did find one bad cap on the xmain a smaller one. I replaced it but it did not fix the problem. I have noted a high pitch noise coming from the powersupply right where another cap is. I guess I am going to start taking some readings to see what my voltage is. Any suggestions?

[tw2005]

Re: Vizio P50 HDTV20A

Check the power to the Xmain and the fuses (1 ceramic, 3 green pico) on that board. There's a Vs and Ve test point on the PCB next to CN4701 where power enters.


Edit: Samsung manual added.

[tom66]

Re: Vizio P50 HDTV20A

X-main fault, IMHO.

[gideon277]

Re: Vizio P50 HDTV20A

Okay voltages going to xmain are 88.8, 88.8 ground ground 6.3 that is going from left to right on the power supply itself no cable connected. I have tried other settings on my volt meter but get 1 on all pins expect last pin which gives me 14. I am at a loss going back to possible power supply issue.

[tw2005]

Re: Vizio P50 HDTV20A

that's a problem in my eyes, should see Vs or 200v or so not 88v?

maybe post#5 is something to consider, watch out for dry joints

[tw2005]

Re: Vizio P50 HDTV20A

What's Vs at the Ymain?

[gideon277]

Re: Vizio P50 HDTV20A

At the ymain it is 89.7, 89.7 and 6.4

[gideon277]

Re: Vizio P50 HDTV20A

I ajdusted my voltmeter up a bit and now I get 207, 207, and 14 that is for x-main and y-main. I am having problems testing for continuity and have a feeling my meter is screwing up.

[gideon277]

Re: Vizio P50 HDTV20A

Okay found a bad inline fuse on the x-main board just did a temporary jumper to test the theory and bingo it worked. I should be able to replace that fuse tomorrow and t.v will be working. I suppose I could just leave the jumper in place but I would rather fix it properly.

[tw2005]

Re: Vizio P50 HDTV20A

Okay found a bad inline fuse on the x-main board just did a temporary jumper to test the theory and bingo it worked. I should be able to replace that fuse tomorrow and t.v will be working. I suppose I could just leave the jumper in place but I would rather fix it properly.

Which fuse? Post a picture of it working and definitely get the right fuse in case there is an issue of too much current draw.

[tw2005]

Re: Vizio P50 HDTV20A

I ajdusted my voltmeter up a bit and now I get 207, 207, and 14 that is for x-main and y-main. I am having problems testing for continuity and have a feeling my meter is screwing up.

I've seen this before with other meters used in posts. A good quality autoranging meter is a sound investment.

I have a 20year fluke I picked up for $30 and it's excellent, ex government disposal.

[gideon277]

Re: Vizio P50 HDTV20A

This is what the menu is supposed to look like compare to the first photo I submitted on this post.