Sanyo 50747 No picture except 1 inch bar at top

[Sanyo'momma]

I got this plasma TV from a friend wih the hope of replacing a fuse a cap to fix it but the fuses are good and I don't see any bad caps. The voltage readings are within specification. I was told that it may be the buffer boards but how can I be sure? Any help is much appreciated.

[tom66]

Re: Sanyo 50747 No picture except 1 inch bar at top

Usually the only causes of a vertical display fault on a plasma are the buffers, however, it is quite rare for multiple buffer drivers to go bad - there are several on each buffer, typically 12-16 for the whole display. Does the top part work perfectly, good picture, or does it just light up? Did it go wrong all at once, or slowly develop?

[tibimakai]

Re: Sanyo 50747 No picture except 1 inch bar at top

Make sure that you are on the menu screen.

[Sanyo'momma]

Re: Sanyo 50747 No picture except 1 inch bar at top

There is only a 1 inch color bar across the top of the screen. Other then that, there is no picture. Sound works fine but no matter which input I use there is no picture.

[cadiman]

Re: Sanyo 50747 No picture except 1 inch bar at top

What color bar and what color is the screen?

You may need to turn the lights off. You may see the screen light up grey in the dark with the color bar at the top.

Lit screen with a 1 inch or bigger black bar is a failed buffer chip or ribbon cable not installed correctly.

Again, get the NEON bulb voltage tester and check for high voltage at the buffer board test point. (hardware store should have them) They are great for checking voltages above 90 volts or so. That will tell you if the y board is sorta working.

check by holding one lead with your finger and touch the other lead to the buffer board test piont. (NEON BULB TESTER ONLY)

I always start with that then go to the z board. (if the power supply checks out)

You may have multiple problems with this tv.

[Sanyo'momma]

Re: Sanyo 50747 No picture except 1 inch bar at top

The bar is colored snow and the rest of the screen is charcoal black as if there is power going through it but no picture.