9200 color transistors

roothorick

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This makes sense in my head, but I thought I'd run it past people smarter than I.

I've got the color-out issue on one of our two 9200s. I already made a thread about this monitor here but I got a different question now. mecha187 suggested replacing the resistors with a higher resistance and replacing the color transistors with a beefier NTE2501 (higher max voltage). However, as he admitted, it won't look as good, and since this is an in-the-field machine that's expected to make money, that's not desirable. I want to take a slightly different approach -- use the current 1.35kOhm resistors, replace the color driving transistors with NTE2501s as they die, at the same time fitting them with significantly larger heatsinks (I'm thinking 3W@25C). Will that work out? Could the larger hunks of aluminum screw with the magnetic fields in the tube?

-E- You know, I now have a 9400 neckboard that doesn't have a tube to go with it. It has "H." (Hitachi?) 2SC2682s on it. Slightly lower voltage tolerance, but it just might work.
 
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Larger heats sinks are fine. You should have any interference issues....
 
I had the same problem on a couple D9200s. a 3rd one actually hasn't given me any problems in the last 2 years (almost).. but anyway, I talked to Chad at arcadecup about this, and apparently there's two causes for why these burn out quickly on some monitors.

one, the factory resistors kinda suck, I used these as a replacement: http://www.mouser.com/Search/Produc...K5Evirtualkey58810000virtualkey588-TWM10J1K5E

I went ahead and replaced all 3. then, the next thing to do is to go into the on-screen menu and turn down the RGB values. I wanna say stock they run at about 3/4 of the way (whichever value that is) dialing those down will put less stress on the drive transistors.

I figure for the money you'd be better off replacing all 3 resistors and transistors and just be done with it. not that I object to your idea about the bigger heatsinks though, I'm just letting you know what I did on 2 horrible monitors we got in some Sega NAOMI games in our arcade that worked. :)
 
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