6 Jun
2009
6 Jun
'09
10:17 a.m.
I plan to
connect them all to the RK07 Field Test Box to see in what
shape they are. They should all be OK ...
They probably are... in my experience, they are very sturdy
mechanically and electrically.
I was cleaning and prepping for sale a pair of them about 21 years
ago.. one was just fine, but when I flipped the breaker on the second
one, *huge* amounts of thick black smoke poured out of the PSU. I
slapped the breaker off and tipped back the PSU to see what happened -
two of the rectifier diodes (1N4007 or similar) were charred and
perforated. A few minutes with a DVM narrowed down the problem to a
completely-shorted filter cap. It was great that it was held in with
#8 bolts, not solder. The "hard part" of the repair was replacing the
diodes.
Lots of smoke + two $0.07 diodes + one C-battery-sized filter cap ==
working drive!
Excellent...
Reminds me of the time smoke poured out of a 3rd party (Plessey IIRC)
Unibus expanison box. It was clearly coming from the PSU area and I
thought I could see something glowing orange inside. Turns out (after
takign the PSU apart) that a bridge recifier had shorted and the orange
glow was the wires linking that to the transformer -- all the insulation
had burnt off and they were more than red hot. Replaced the rectifier and
thw wires, no problems...
-tony