11/45 progress

From: Tom Uban <uban_at_ubanproductions.com>
Date: Sun Feb 13 19:53:09 2005

>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.

I would suggest replacing the bad switches if you have spares. My experience
is that they don't tend to get any better. YMMV.

>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.

I would remove all of the cards and test the power supplies solo. They
should regulate fine without a load. You won't be able to adjust the final
voltages until they are loaded, but you can check if they are in range.

>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?

Speaking of the backplane, you should be sure to check for bent pins before
you proceed with the power supply check. Also, you can look in the unibus
pin list for which power and check the power on the backplane at these pins.
They are fairly obvious based on the wire size and color as well.

--tom
Received on Sun Feb 13 2005 - 19:53:09 GMT