3178 WITH MISSING CAP, NO VERTICAL DEFLECTION
I originally received three 3178 terminals, each with its monitor, keyboard and logic element. Number one is in service now with a decent brightness, number two is quite dim but works and the third had no vertical deflection. In that last monitor I found an electrolytic capacitor that had committed suicide and part of the PCB trace connected to it was damaged.
I bought a replacement capacitor and opened the monitor to make the repair. I used jumper wire to bridge the bad traces. The reason I am doing this is because the trace is acceptably bright, unlike the very dim terminal number two that is otherwise functional. I had a good monitor PCB to compare to be sure I repaired the burned trace properly.
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| Reference board |
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| Board with damaged trace |
I installed the new capacitor and a bridge wire to restore continuity for the circuit.
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| Repair made |
I then fired up the monitor to compare it to terminal One that works well. The good news is that I restored the vertical deflection. However, the image looks terrible. I suspect that I have to adjust focus and do a bit of cleaning in the hope that this will sharpen up acceptably.
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Monitor with replaced cap and repair |
Will download the manual for adjustments and see whether I can get a decent image or this terminal goes on the recycle list.
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