G07 white screen

[bonedoc]

So, I bought a mint centipede with a g07 monitor. The monitor was dead. The seller said the screen was getting more narrow over time and eventually went dead. I tested the HOT transformer, and it was dead. So, I replaced it and its fuse. This brought it back to life, sort of...

The monitor powered on and has a white line about 3" wide and it went vertical.

I then did a complete cap kit, and this fixed this issue. I now have full screen....but....

The screen is white and has some vertical lines on it. The game is playing, but the screen just shows nothing. Any ideas as to the cause?!

[bonedoc]

Sorry, that pic should be rotate 90 degrees to the right.

[MonMotha]

Turn down the "screen" control on the flyback.  Does the situation improve, or does it just go black?

[bonedoc]

Hey there. It just goes black.

[buffett]

check R517 it may be open or way out of tolerance.

reflow all your header pins on the chassis as well.

Peace
Buffett

[bonedoc]

Ok, I tested r517 and I am getting about 23k Ohms. Is this right?

I did reflow the headers, but I never reflowed the neck board. Maybe I should do this.

[bonedoc]

Ok, I need to add something....

I also tested r516 and it is doing the same as r517. When I measure them, they both start out at 18k ohms and drift slowly up to 23k ohms. I find it odd that they are drifting. I made sure it wasnt a meter problem and measured a 1k 1% resistor.

I have read different values on r516 and r517, but what I have read is the 180-200k range. So, Im guessing these may both be a problem?

Does anyone know what these values are supposed to be?

What are they used for? A voltage divider?

[buffett]

did you lift a leg and measure them out of circuit.
you need to do this with all resisters.

R517 is 180k

r516 is 150k

i do knot know what they are used for officially.

but i do know they control the screen voltage/brightness.

Peace
Buffett

[bonedoc]

I cut a leg off each resistor and measured. R517 is 187k Ohms, and R516 is coming in at 10k Ohms.

So, 517 is good and 516 is way low. I hope this is the issue ;-) I suppose this could be why I have to turn up the brightness really high to see anything....

[buffett]

could quit possibly be.

edit your post so the info is correct about R516.

Peace
Buffett

[bonedoc]

I was wrong! Both of the resistors were fine. I accidentally measured the 10k resistor next to r516. Back to square 1.....may just have to get a new monitor.

[buffett]

you could send in the chassis for repair.

i repair those model chassis.

visit my site and shoot me an email.

thearcadebuffett.com

Peace
Buffett

[MonMotha]

Is there any color on the monitor or is it just white/gray?  It looks white to me in the picture, but I'm trying to make sure the picture isn't lying.

If it's actually one color primary, you may have a bad drive transistor.  If it's white, it's probably somewhere else.  Unfortunately, I'm not particularly familiar with the G07, but they're very common so somebody on here will probably chime in if you can get enough info to ring a bell with somebody who's seen the problem before.

[Ken Layton]

The signal input cable is plugged in, isn't it?