Asteroids PCB Issue

Ravage

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Hey All!

Has anyone seen a Asteroids pcb behave like this?

astprob.jpg


Basically very quickly from boot up it seems liek the pictures behinds to breakup from the bottom of the screen - obviously a chip failing under load, but wondering if anyones got a heads up where to start looking...

A fuller view of ti can be seen on thsi video (its only 1meg) at:

http://www.retrokade.com/temp/astprob.mov

Cheers Rav
 

DanP

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I'd look at the op amps (tl082's?) and voltage regulators first (+/- 15v). It looks like the CPU/DVG is working fine, just the final output stage. I take it other PCB's work fine with this monitor?

Dan
 

Ravage

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This isnt my machine, but the owners faulty board did display the grid normally on the screen and indeed he did get 30 mins gaming out of this pcb before it died so Im presuming its the pcb - plus he says its starts ok so yeah presumably something dyings/overheating on the pcb

Thanks for the tips where to start!
 

guddler

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I'd be just as suspicious of one of the transistors on the monitor seing as it's half of the entire Y axis playing up. At least until you can somehow confirm it's not the monitor.
 
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