[vcf-midatlantic] Wrap-up of System Source Repair Workshop 1/29 & 1/30, 2022

[Mike Loewen]

On Sun, 30 Jan 2022, Jeffrey Brace via vcf-midatlantic wrote:

> Maybe others want to chime in on what they were working on.

    I was only there on Sunday. My project was to evaluate the two HP 3000 
Series 30 systems owned by System Source.

    One system was an empty cabinet, but the boards and cable were eventually 
located. I populated the card cage with the requisite boards, and added the 
necessary cables to connect to the system console and serial terminals, and 
the HP-IB devices (disc, tape and printer). On power up, only one of the fans 
turned on, and there were no DC voltages.

    The boards in the card cage are:

 	Bus Interface Controller
 	CPU
 	Firmware PCA
 	Maintenance Interface
 	GIC (General I/O Channel, HP-IB interface)
 	GIC
 	ADCC Main (Asyncronous Data Communications Channel)
 	Memory Controller
 	128K Memory Array
 	128K Memory Array
 	128K Memory Array
 	128K Memory Array

    I switched to the other system, which had some of the boards installed. 
This system powered up. The +5, +12 and -12 DC voltages were within tolerance, 
but the +5M, +12M and -12M memory voltages were absent. There are two boards 
in the memory power supply which are suspects (the fuses are okay).

    Back to the original system, I found a blown 3A slo-blo fuse. A search for 
a replacement yielded nothing on hand (or at NAPA Auto Parts). I elected not 
to swap the good fuse from the second system, since that was the only one we 
had. If, after obtaining new fuses, the power supply on the first system comes 
up, we could consider swapping out the memory power supply boards. 
Substituting a modern power supply is also a possibility. The CE manual lists 
the the power requirements for the memory supply as:

 	+5M	5.0A
 	+12M	3.5A
 	-12M	0.38A

    I also checked out the 2621P terminal to be used for the console. It powers 
on, passes the self-test, displays correctly and types in local mode, and the 
integral thermal printer is working. The battery which maintains the 
configuration is dead, and should be replaced with a Mallory TR133 or 
equivalent. A cable to connect the terminal to the system console must be 
obtained or built. The cable part number is 13222N (13222-60001). If you're 
building one, the diagram is on page 22 of the Terminal Cable Handbook:

 	http://www.bitsavers.org/pdf/hp/terminal/5957-9918_terminalCableHbk.pdf

    A longer cable is part number 92217A. There are currently one of each 
listed on Ebay.

    System Source also has two 7970E tape drives (1600 bpi), two 7925 
removeable pack disc drives (120MB), two 2631A printers, and a 2608A line 
printer. All of these can be connected to the HP 3000 system, and will need to 
be evaluated.

    There were no disc packs found for the 7925 drives. If they cannot be 
located, disc emulation via HPDrive would be an option. I had a PC with 
HPDrive installed in case testing got that far, as well as 9-track tapes to 
load MPE-V/R.

    Another ribbon cable is required to connect an ADCC Extend board to the 
ADCC Main board, to add four more serial ports. The part number is 
31265-60002. To make one, you would measure the contact spacing on the upper 
ADCC frontplane connector and obtain two 50-pin edge card connectors and a 
short piece of 50-pin ribbon cable. The cable connects the upper frontplane 
connectors on the ADCC Main to the ADCC Extend board to its right.


Mike Loewen				mloewen at cpumagic.scol.pa.us
Old Technology				http://q7.neurotica.com/Oldtech/