PDP8A Questions

From: nbreeden2_at_comcast.net <(nbreeden2_at_comcast.net)>
Date: Fri Nov 21 15:20:30 2003

All,

  I was recently given a PDP8A, it's the model with dual power supplies and the 20 slot backplane. It has both the mini-panel and the operators panel. I've been working to get the system operational and have several questions:

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  The unit won't power up, I have been able to troubleshoot this down to the Triac (D7) on the BA8-C that is used to switch AC power to the main transformer. I believe this Triac is bad. (Note: I do have AC power to T1 on the BA8-C PCB.)

  With the Triac bypassed the system comes up and basic items check out from the operators panel.

  Does anyone know what a replacement Triac part number would be? I only see what I believe are DEC part numbers.

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  In the print set for the BA8-C the circuit that controls AC power is shown, the circuit uses an opto-isolator. In the schematic one side of the opto-isolator's LED goes to J12-B2, the other side of the opto-isolator is labeled OC1-2 (OptoCoupler 1 pin 2 I assume).

  Does anyone know where this pin actually goes?

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  I'm assuming that the G8019 board controls switching of the AC power via the opto-isolator.

  Is this a correct assumption?

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  I have an RL02 controller/drive/disk with the system, what steps do I need to take to boot from this drive? I don't have an operators manual at the moment.

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-Neil
Received on Fri Nov 21 2003 - 15:20:30 GMT