[vcf-midatlantic] PDP-11/10 PSU Repair/Warning

systems_glitch systems.glitch at gmail.com
Wed Jun 5 16:54:24 EDT 2019

full writeup here: http://www.glitchwrks.com/2019/06/05/pdp1110-psu-repair

I finally fixed the power supply in my PDP-11/10S, it turned out to be a
shorted bridge rectifier on the 5411086 board, which provides +15 VDC, LTC,
and AC LO/DC LO. Unfortunately, when it failed, the rectifier burned up the
edge connector traces for the AC input to the board. I ended up cutting the
edge connector traces away (what was left) and soldering on a pigtail to
connect to the Mate-n-Lok coming from the AC transformer. I added a 15A
inline fuse, in the repair.

For those who have original 5411086s that haven't failed yet, you might
want to make up a little pigtail with an inline fuse holder. It'd be easy
to make up such that it could plug into the existing harness without
permanent modification, and it'll save your edge connector traces if the
rectifier shorts. It can happen in the other regulator modules too, but
they use a Mate-n-Lok instead of an edge connector, so any damage would be

Anyway, the PDP-11/10S is back up and running!


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