NIM Power Supply Fix

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Aidan_Roy
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Re: NIM Power Supply Fix

Post by Aidan_Roy »

John,

I edited the original post labeling the pictures. I labeled them based off of the orientation that the module would be sitting in in the bin.
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Rich Feldman
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Re: NIM Power Supply Fix

Post by Rich Feldman »

Could anyone use a free spool, or two, of the narrow waxed ribbon used to lace up wire harnesses?
Then you can make your restoration, or hack, hard to distinguish from the original. :-)
All models are wrong; some models are useful. -- George Box
John Futter
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Re: NIM Power Supply Fix

Post by John Futter »

Aidan
What i meant
please pull each circuit board out of its edge connector and photograph it please
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Aidan_Roy
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Re: NIM Power Supply Fix

Post by Aidan_Roy »

John,

Here are the boards.
Attachments
HV Regulator Board back
HV Regulator Board back
HV Regulator Board front
HV Regulator Board front
LV Supply Board back
LV Supply Board back
LV Supply Board front
LV Supply Board front
John Futter
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Re: NIM Power Supply Fix

Post by John Futter »

Aidan
there are not many components you can check all resistors with a DMM look for carbon ones that have gone high in value
cap lift an end and measdure capacitance
transistors use the DMM diode function to check BE BC EC CE

you still need to try and find where thr three wires from the pot should go --use a magnifying glass to check possible solder joints /connections
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Aidan_Roy
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Re: NIM Power Supply Fix

Post by Aidan_Roy »

John,

Honestly, I’m not sure it’s worth it to try and fix. I can either return it and replace it with a known working one or I can harvest all of the still good components for later use and replace the PSU anyways. The more I look at it, there just doesn’t seem to be a high chance of this thing being repaired to its original state.
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Richard Hull
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Re: NIM Power Supply Fix

Post by Richard Hull »

Aidan, I assume you are in the U.S.? if correct, I might buy offer to buy it it if low enough in price. Remember I collect Nuclear Chicago stuff. I might try and repair it or just add it to my collection of N.C. broken.

With no metering, it is not a great piece to own for NIM work. I noticed they changed their really cool logo on the label. Boo, hiss...

Richard Hull
Progress may have been a good thing once, but it just went on too long. - Yogi Berra
Fusion is the energy of the future....and it always will be
The more complex the idea put forward by the poor amateur, the more likely it will never see embodiment
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Richard Hull
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Re: NIM Power Supply Fix

Post by Richard Hull »

A follow up. I did buy the supply non-working from Aidan and fixed it this morning between midnight and 5 AM. It turns out someone had been soldering in the supply. Probably they were trying to troubleshoot via disabling various sections. I cleaned up their solder joints. I ultimatedly found one bad transistor on the multi-transistor control board and two 9.5 volt reference diodes. Tweeked the pot on the board to fine tune the 500 volt switch output to true 500 volts. (it was 480 volts before the tweek.)

Now it will joined other Nuclear Chicago items I have, but as a now working item.

I note that based on the manufacture's tagging Nuclear Chicago had been sold to Searle Ind. and was now claimed as a division of Searle. Nuclear Chicago lost it identity some time in the 70's.

Richard Hull
Progress may have been a good thing once, but it just went on too long. - Yogi Berra
Fusion is the energy of the future....and it always will be
The more complex the idea put forward by the poor amateur, the more likely it will never see embodiment
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Aidan_Roy
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Re: NIM Power Supply Fix

Post by Aidan_Roy »

Richard,

I am glad you were able to repair the unit. I saw a few solder joints as well and tried to see if the broken wire was supposed to go to one. Since none were correct, for reasons you have now made known, I left some messy. Not more than 2 though. As far as the bad transistor, I would not have had enough justification in finding a flaw like that so, I’m glad that all worked out well. Thanks.

Aidan
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