No more Blue on Sanzo 20-EZV

[Hiub1]

Hey guys, did my first cap kit on this monitor yesterday, a Sanyo 20-EZV. Everything went smoothly other than a few traces that had lifted up, which I fixed by bypassing them with some wire.

When I turned it on for the first time, nothing blew up, and the image looked great. I was trying to get rid of jailbars that the monitor had, but the cap kit did not solve the problem. The colors were a bit brighter, and the picture was nice and sharp.

Today, I went to turn the monitor on, and after adjusting the brighness for a bit I got it where I wanted it. I went to put the back door on the cabinet, and when I went to look at the monitor again it had a horrible blue tint. I didn't feel as if I bumped anything or anything of that sort.

After messing with it for a good while, I figured out that there is no blue being output to the tube. If I turn the Blue Bias pot, nothing happens until I get close to being rotated fully clockwise the screen regains the blue tint, but the actual blue being output to the screen doesn't really change. Ex. the blue parts of the font in R-Type do not display. Also, when I turn the Blue Drive pot, nothing happens. Could it be that this pot is broken?

I unplugged and plugged in all connections to make sure that there was not  a problem there, and I still get the same symptoms.

Any ideas?

Thanks in advanced, Fred.

[Kevin Mullins]

Have you swapped color input signals around to verify that you actually have a blue signal coming in?

ie: switch the red and blue signal wires

You can ohm the pot to see if it's broken.

Did you also check the ribbon cable connection between the signal board and the main chassis? (assuming that you are using the original signal board)

Just gonna poke at the simple stuff before going into transistors and/or the tube itself.

[Hiub1]

Hm, good idea about switching the wires. Just got a molex pin remover that will come in handy. I will check the pot as you stated. I believe that I have checked every connection on the monitor. Let me go do that, and I'll be back wiht some answers.

Thanks for the help! Fred.