29 Nov
2000
29 Nov
'00
6:28 a.m.
Rob Kapteyn <kapteynr(a)cboe.com> wrote:
So does anyone have any tips on firing up this old monster ?
It it rather precious to me and I don't want to blow it up.
I guess I should just take out all of the cards and check out the power supply
first.
I have heard that old capacitors can dry up and fail catastrophically -- but I
think that this applies
to the 1950's capacitors, not the 1970's ones.
Hi
You should bring the main supply up slowly on a variac.
Any electrolytic capacitor can blow. Do remove all the boards,
including the front panel. When you turn things on the
first time, turn the power off after a minute or so and
see if any of the tantalums are hot. These also fail with
time and tend to flame. Make sure to point that chassis
away for people and windows. When the large ones blow it
can be dangerous.
Check the voltages after installing each card.
The rest is just locating bad chips. Most older RAM boards
will have at least one bad RAM on them. Write a simple
test to check these. I wrote a simple one that could be
quickly entered from the front panel that just did a
checker board/ checker board bar type pattern that worked
well. Most likely a GALPAT would be better but one should
restrict that to one RAM bank at a time to save from wasting
time. I do recommend that you do at least one simple march
and reverse march ( half of a march C ) over the entire
memory bank to look for address faults.
Dwight