11/45 progress

Jay West jwest at classiccmp.org
Sun Feb 13 16:01:39 CST 2005


Well, lots of progress was made on the 11/45 front this weekend. I finished 
the entire physical/cosmetic restoration today. Some interesting tidbits & 
questions:

I had to desolder 9 switches & covers from a spare 11/70 panel to replace 
disintegrated switches on the 11/45 panel. Most of the switches work well 
and feel solid now, except several of the momentary return switches on the 
right side of the panel don't quite return all the way. I can feel the 
springs are active and present, but just not strong enough. I am hoping that 
just working the panel switches a lot will get these spring returns to work 
better. Perhaps I'm deluding myself and will need to replace them from the 
11/70 front panel as well.

Reattaching the front panel was interesting, a previous person had 
overtorqued one of the nylon screws too tight and it had broken off inside 
the standoff. I one-upped them by doing the same thing. I tried drilling out 
the two nylon screws to no avail. I decided to try to melt them out. Who 
would have thunk of using a blowtorch on an 11/45 front panel ;) Interesting 
physics... within about 10 seconds of being in the flame... I'm guessing the 
trapped air inside the standoff expanded, because the screw unthreaded 
itself and backed all the way out. Cool.

The next steps will be power supply checkout and front panel. It has been 
suggested that I power it up with a minimal card set. That's fine and what I 
would normally do; however, I was wondering if it was ok to pull every card 
including the cpu set and power it up, just to check the voltages on the 
backplane.

Speaking of which, how can one test the voltages without an extender card? 
Maybe hunt down the right pins on the backside of the backplane?

Then I've got a question about termination, but I'm still going through some 
documentation to see if I can figure that out myself.

Thanks for any thoughts!

Jay








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