PDP 11/34a Console dead, powersupply problem?

Andreas Holz asholz at topinform.de
Wed Jun 11 01:31:28 CDT 2008

Hello all,

just tried to power up one of my 11/34a and found it's console dead:
Power on LED and adresse display are not lit.

The PSU fans are running. Using the field maintenance print set for the
11/34a and docs provided at bitsavers I checked the voltages at the
backplane and found the +5V Voltage seems to be out of range.

Are there any docs, advices and procedures to check an repair a H7441

Looking at the bottom side of the PSU untit there are three PSU's, two
H7441 with a red LED, the LED of one H7441 is lit, and a H755 with a 
bulb, which is not lit. What is the meaning of these LED and bulbs?


More information about the cctech mailing list