Sharp xm-200 color missing

brainmegaphone

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So I have a Sharp XM200 in a Donkey Kong. It looks like blue is missing or maybe white? I can't see the word "oil" on the can in Donkey Kong or the initials to enter a high score. I'm going to be doing a cap kit but my experience with K7000s tell me I have a transistor problem. Can I short a neck board transistor to prove this theory out?
 
There is no 'white' color for a CRT. If at any point you can see a green, a red, and a blue color on screen you have all of your colors working. You can absolutely short out a transistor or the neck pins directly to see if your tube has a working color gun.
 
I was sitting in a doctors office and worded it correctly... Whatever "color" the word "Oil" is and whatever color the initials are on that entry screen is what is missing from my image.
 
The attached image may be helpful... See how there is no "oil"
 

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looks like there is no green

I guess I'll short the transistors first to see... I'll also stick my rejouv kit on it as another person suggested to test the tube. Only used that one time in 3 years but it may come in handy here!
 
Shorting the transistors on the neck board results in the appropriate colors coming on the screen. I assume I have some bad traces (solder joints) or bad parts in the color paths which I see in the Sharp troubleshooting guide. I guess I'll cap it and then test the transistors while I have it out.

Ian - do you have these transistors in stock? Q801-803? 2sc2068 per the schematics...
 
So I wanted to post an update on this one... I did a full cap kit and paid close attention to re flowing the green circuit area very carefully. I also checked each component in the green circuit against its red or blue counterpart. Nothing looked out of spec. Pots tested perfectly as well.

Plugged monitor back in - green was back for awhile then gone. I pressed down on parts and areas and juggled wires and everything to identify the problem. No luck.

Then I turned the inversion switch off... image inverted (duh). Turned it back on. Image back to normal WITH green. Green worked for a couple hours last night no issue.

I'll have to see how it is tonight - and I'll have to look at the switch's solder points when I pull monitor again. Not sure if I have a defective switch (seems unlikely) or bad solder around it.
 
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