Vizio VP50 HDTV20A No picture/ yes sound, what am I missing?

[crumbliss.r]

So, I think my Y-sus boards need to be replaced, but I am not sure. I have all the correct voltages out of the P/S going to both the Y and Z boards... Tv turns on with sound, LED 2001 comes on solid on control board, 2002 blinks steady, Power LED on front of TV is solid green.

I have tested every point I can find to test, All fuses are good, All Caps appear good, I checked for S/C on the YSus board according to youtube videos, all appears to be good, but still no picture. I have adjusted the Va voltages to within 1 volt of the chassis reccomended voltage, I am stuck and need help.

Is it possible that the Y board is bad, but everything tests good? Is there some trick to determine it is in fact the y board without spending the 100 bucks for a new one?

the boards are as follows...
Upper Y LJ41-05121A
Lower Y LJ92-01492A
Y Sus LJ92-01399A/B/C/D
Z Sus LJ41-05171A
P/S PSPF561A01A

I did not include pictures because there are a bunch already on here in other forums and figure if you know enough to help me, you probably already know what those boards look like. If you want specific close up pictures of any area, I can provide.

[maxvalutech]

Re: Vizio VP50 HDTV20A No picture/ yes sound, what am I missing?

Your post doesn't say if screen lights up as it should if all voltages and operation is ok. The boards that make the picture are main and control. Do you get menus, what about test patterns are they available? Do any of the inputs work?

[crumbliss.r]

Re: Vizio VP50 HDTV20A No picture/ yes sound, what am I missing?

my apologies. Screen is completely dead. No flicker, nothing happens at all when you turn on power. However the buttons do work, as I can change the input and adjust the volume.

[aaronwt6]

Re: Vizio VP50 HDTV20A No picture/ yes sound, what am I missing?

Look very closely at the ICs on the Y-Buffers. Typically, on a no picture scenario you will have one or more of them blown which in turn causes the Y-Main to fail. For whatever reason, it's almost always the top one or two on the upper buffer but can be any of the others as well. Looks for a large bulge or crack in them and also underneath for discoloration on the bottom of the board from the IC overheating.

[crumbliss.r]

Re: Vizio VP50 HDTV20A No picture/ yes sound, what am I missing?

In looking closer at the YSus board and the buffers, I found a bad cap on the Sus board that I will be replacing. I looked closely at the Buffer ICs and found no signs of damage, burning, holes or any evidence of fault. I will let you know what happens when I replace the Cap tomorrow, with pictures.

[aaronwt6]

Re: Vizio VP50 HDTV20A No picture/ yes sound, what am I missing?

Sometimes replacing that cap will resolve the issue, but many times it's a sign that more damage has occurred on the Y-Main by the time it's noticed. I've never done a component repair on one of those but it's likely that just changing the cap will not resolve the issue. There is another 50V 100uf cap near the buffer connections that often fails along with the one near the fuse. Check it out as well. I don't have one in front of me but if my memory serves me well, the two that fail are both 50V, 100uf.

[crumbliss.r]

Re: Vizio VP50 HDTV20A No picture/ yes sound, what am I missing?

Replaced that Cap, no luck. It is a 25v 680uf cap, replaced with a 25v 1000uf cap (closest I could get locally). I am to the point where I think I need to go ahead and replace the Y Sustain. Both of the Y buffer boards check out ok when I did the test where you check for shorts across the input to the ribbon outputs. No faults at all in the buffer boards. I have the correct voltages into the YSus, so I figure it is either the Ysus or the logic board that have gone bad. I have no idea how to test either of those, unless someone lives around the Seattle Washington area and has a good set we can test these boards in.

[aaronwt6]

Re: Vizio VP50 HDTV20A No picture/ yes sound, what am I missing?

Did you check for shorts on the Y-Main itself? How about the VSC voltage? A 1000uf cap is really too far out of spec to use there. Bad idea. Sorry for misstating the rating about but you are correct on the 680uf rating.