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[TASS] A Fix At Last!
Some of you may recall that I had a temperature related intermittent in the
RA drive. I eventually traced it down to missing pull up on a 7403. The
RA drive has been driving me mad. TOM up on the roof has continued to have
a temperature related RA problem. I would go up and look on the back of
the board to make sure I had installed the pull ups. Yep, they were there.
This problem continues to mess up images since sometimes the RA drive
skips and that causes improper RA motion. A couple of days ago, it got
cold enough that TOM would simply not run.
Today, I set up a system on the bench and with my new oscilloscope put test
points on everything and set out to make it work. I pulled a board from
the stack that did not have the pull ups, and as soon as I put the cold
spray near the RA circuits, it quit working. I added the pull ups and it
was solid. So why would the board on the roof quit?
Well, I went up and got it. Sure enough, there were the pull ups. But I
had just soldered on a set and these did not look right. Soon I realized
that I had put them on the wrong IC. Sigh!
Things are now back together and running the RA exercise program and all
I should take a tip from Santa. Santa checks his lists twice!
OK, all this has been mostly due to me working myself into a snit. I did
not even get much done. But that is always the case. You can just work so
hard, and then it is a net loss. Still, there is a lot done. ARNE is
sitting here complete. MICHAEL is nearly complete. There is still a lot
of testing to do on both, but if I go at a measured pace, I will get it