MCA Repairs

This area is for discussions involving any fusion related radiation metrology issues. Neutrons are the key signature of fusion, but other radiations are of interest to the amateur fusioneer as well.
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MCA Repairs

Post by guest » Mon Jul 09, 2001 5:09 pm

I ran into a similar situation with my Series 30 MCA, which is a couple of generations newer than the 8100 (35 lbs vs 80), but with similar architecture. Mine was dead from the get-go. Fortunately, the engineers at Canberra are very generous with their test points, and I was able to isolate the problem to a bad 12V supply. Narrowing down the problem after that required some board-pulling to isolate the one that was pulling down the supply, then some judicious trace-snipping to isolate the short. This turned out to be due to a bad tantalum teardrop cap ( there must be hundreds used in this box) and a fried 741 op amp in the power supply. Who killed who is anybody's guess. Now that I am close to having a working NaI scintillator setup (I find out this afternoon), I get to find out how it really works.

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