Vizio VP503 HDTV10a Black Screen

[MyHD120]

Re: Vizio VP503 HDTV10a Black Screen (Some Success!)

I put the SU board in this morning with some success. It seems with this hybrid Panasonic that one IC on the SU board CAN take this set down with Black Screen. However, as you can see in the pics, (I rotated them for better clarity) the ribbon cables still need to be adjusted and I have a black vertical bar down the center. Is this (Black bar) due to a misaligned cable on a C board??

Right now the TV is scanning for cable stations and is not shutting off automatically. If there is no input it will shut down after 40 seconds.

[MyHD120]

Re: Vizio VP503 HDTV10a Black Screen

OK. So now I'm totally confused!!!! The vertical bar was not there before I installed the new SU board. At the same time I could not get the set to recognize inputs from Cable, HDMI 1 or HDMI 2 (don't know if that makes a difference). However, I isolated the SU and added the jumper, now there is no black bar, just prime. Oh, man, I'm drowning here!!!

I will be gone until tomorrow morning, please everybody chime in with some suggestions.

[tom66]

Re: Vizio VP503 HDTV10a Black Screen

The horizontal lines are due to the ... difficult way Panasonic connect their buffers. Just a matter of reseating every cable.

The vertical bar could be due to a loose X connector but it could also be a panel failure, hope not though!

[MyHD120]

Re: Vizio VP503 HDTV10a Black Screen

The horizontal lines are due to the difficult way Panasonic connect their buffers. Just a matter of reseating every cable.

The vertical bar could be due to a loose X connector but it could also be a panel failure, hope not though!

X connector??

tom66, did you miss post #102?

[tom66]

Re: Vizio VP503 HDTV10a Black Screen

Remove the SU jumper connection, focus on fixing the horizontal lines.

[MyHD120]

Re: Vizio VP503 HDTV10a Black Screen

tom66; I don't generally go against your recommendations, but here is my question:

If the panel is bad because of the black vertical bar there would be no sense in going any further. So, I disconnected the tabs on the C1 and C2 boards (where the black bar intersects) to see if they had the bonded diodes. I did not see any (see pics). I did remove the D board at one time so those tabs might be misaligned or the C and D boards are bad.

I'm also loading 2 URL's that can be put into your manuals section if you don't already have them. () ; ()

Your sage advise on this black bar/tabs issue would be appreciated.

[tom66]

Re: Vizio VP503 HDTV10a Black Screen

If the bar is permanent, it is the panel.
If it is intermittent, it is more likely to be a connection or C board issue.

[MyHD120]

Re: Vizio VP503 HDTV10a Black Screen

If the bar is permanent, it is the panel.
If it is intermittent, it is more likely to be a connection or C board issue.

(Tom; please comment on post #106)

I think I made a new discovery (?) and need suggestions. In the photos you can see that the vertical black bar was replaced by color moving pixels after removing the tab from connector CB7 on the C2 board. Does this mean it's a bad C2 buffer and not the panel? The bar is 4" wide and runs vertical from top to bottom.

[tom66]

Re: Vizio VP503 HDTV10a Black Screen

That usually happens when a tab is disconnected. Check those green (1?) ohm resistors on the board next to the connector.

[MyHD120]

Re: Vizio VP503 HDTV10a Black Screen

That usually happens when a tab is disconnected. Check those green (1?) ohm resistors on the board next to the connector.

Tom, I think you nailed it. Photos show resistors on connectors CB7 and CB8. CB7's seem to have a burn mark. I will research on how to test these.

[johnboy1313]

Re: Vizio VP503 HDTV10a Black Screen

I was searching for a different issue this morning and came across this thread. I don't know if it's related at all. It just rang a bell when I read your last post.

https://www.badcaps.net/forum/showth...ight=panasonic

[tom66]

Re: Vizio VP503 HDTV10a Black Screen

If those resistors have burnt, the driver (=panel) is probably at fault. There is a rare chance the ceramic cap near it is failed, but I would say quite rare.

[MyHD120]

Re: Vizio VP503 HDTV10a Black Screen

If those resistors have burnt, the driver (=panel) is probably at fault. There is a rare chance the ceramic cap near it is failed, but I would say quite rare.

I might be grasping at straws here, but is there any way to test the tabs themselves to see if they're shorted? Would that tell me anything? I tried continuity testing from the traces to ground on the 3tabs and got a lot of beeps because They are so close together. I hate to give up.

[tom66]

Re: Vizio VP503 HDTV10a Black Screen

With and without the tab installed test across C224 for resistance. Near zero would indicate a fault; if it's near zero when not installed then it could be that ceramic cap instead.

[MyHD120]

Re: Vizio VP503 HDTV10a Black Screen

With and without the tab installed test across C224 for resistance. Near zero would indicate a fault; if it's near zero when not installed then it could be that ceramic cap instead.

There are 6 caps on this board like C224. All show zero resistance. However, testing with a Blue ESR meter (which I'm not sure I'm reading right) shows an ESR of 5.2 on the suspect caps. The other 4 caps show a 3.7/3.8 ESR

[tom66]

Re: Vizio VP503 HDTV10a Black Screen

You need to test with the panel ribbon off, have you done this? A blue ESR unfortunately cannot test those caps. Pull 'em off and test out of circuit.

[MyHD120]

Re: Vizio VP503 HDTV10a Black Screen

You need to test with the panel ribbon off, have you done this? A blue ESR unfortunately cannot test those caps. Pull 'em off and test out of circuit.

Yes, the panel ribbon was off and the board removed from the set. I will remove the caps tomorrow and test. Thank you.

[MyHD120]

Re: Vizio VP503 HDTV10a Black Screen

With and without the tab installed test across C224 for resistance. Near zero would indicate a fault; if it's near zero when not installed then it could be that ceramic cap instead.

OK. I'm just completely lost by what you're saying above. I removed C224 and tested across the cap and the tabs and got "0.F". "if it's near zero when not installed then it could be that ceramic cap instead". I'm sorry, but, could you be a little more clear? You're dealing with a bonehead here.

[tom66]

Re: Vizio VP503 HDTV10a Black Screen

C224 and alike parts are all ceramic capacitors.

A ceramic cap consists of very thin alternating layers of metal and dielectric (ceramic type material.) A dielectric is a really good insulator with properties that are good for capacitors.

These capacitors have quite high capacity (though not as high as an electrolytic or tantalum) and extremely low ESR, but are very vulnerable to surface and internal fractures. Cracks in the ceramic can cause the metal plates to touch, causing a short circuit.

Cracks are often caused when the board is flexed or installed, or the connector is moved. Sometimes they are there at the factory production time, not causing any issue, then when the board is manipulated they crack.

It is nice if that is the cause, as this part can usually be replaced. And, it would be rare for a plasma panel that worked perfectly before having SC/SU/SD/SS etc failure to then have the panel fail, as they usually fail due to minor defects in the drive ICs which cause catastrophic failure -- rarely do they fail after not being used for some time.

[MyHD120]

Re: Vizio VP503 HDTV10a Black Screen

I almost feel as if I'm harassing you Tom. I appreciate the info on ceramic caps. However, it doesn't tell me, with the measurements, what could be wrong. So I ordered a TNPA4433AB C2 buffer board. I have to assume that I might burn this new board out if there is another problem lurking in the wings. Do you have any guidance?