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everten

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I recapped the chassis on my Blast City MS-2930-S and everything was working fine, I had to pull the chassis out to replace 4 big capacitors that shipped late. Once I got it all back together the vertical position is no longer adjustable.

Looking for some guidance on all the places I should check. I’m guessing the adjustment pot could have gone bad, but I’m worried this is something with the chassis.
 
Last edited:
did you reflow anything else,check remote board solder joints both ends and continuity test the wires
are you getting full screen just no adjustment?
 
Didn’t reflow anything. I’ll check continuity.

The picture was full screen when I booted and I went to cross hatch to make adjustments. When I shrunk the vertical size it when down and then got stuck.
 
I may have mixed up the issue in the original post. I’m troubleshooting now and it’s the vertical position that won’t adjust.

I confirmed the potentiometer is good and the values at the remote board match those at the chassis connector.
 
Anyone have a schematic for this chassis? Q402 is hanging on by a thread, definitely broken connection. Might not be able to salvage it. Legs are pretty much gone. Possible replacement part number?

49738961506_38d2c1fc99_z.jpg
 
FIXED!

I was able to bridge some solder on Q402 which fixed the issue. I found on a quick web search that Q401 and Q402 might be vertical deflection transistors, but cannot verify.

I also discovered what caused this. I slid the chassis PCB backwards into the black tray after recapping. There's a screw post that sticks up in the exact spot of Q402 which must have ripped it off.

If anyone knows a part that would replace this please let me know. I don't trust this to hold in place forever. I used some kapton tape to keep in down just in case.

49739533612_05eca85e98_z.jpg
 
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