Amid a migration project, Michael Anderson was facing a failure. Not of his project, but a failure of his HP 3000 to start up on a bad morning. HP's original hardware is in line for replacement at customers using the 3000 for a server. Some of these computers are more than 15 years old. But the HP grade of components and engineering is still exemplary.
"I was working with a HP 3000 Series 969, and one morning it was down," he reported. "All power was on, but the system was not running; I got no response from the console. So I power-cycled it, and the display panel (above the key switch) reported the following."
Proceeding to turn DC on
On the console it displayed garbage when the power was turned on, but the message on the display remained. I wasn’t sure what to replace. I was thinking the power supply — but all of the power was on. As it turned out, even in the middle of a power supply failure the 3000 was working to get out a message. The back side, the core I/O, FW SCSI, and so on, all appeared to have power. That is why I found it hard to believe that the power supply was the problem.
He explained that (back in the day) HP engineered some of the best power supplies in world, lots of checks and verifications. Even though the power supply had actually supplied DC power to the various components, it was not able to verify it.
So the message "Proceeding to turn on DC power" remained on the front panel display, meanwhile the boot process on the console would hang, and if you do a <cntrl-B>, RS it would time-out with a msg:
"FATAL ERROR: System held in reset. POW_ON never came back (APERR 21)"
"Waiting until it's reasserted......"
Bill & Dave's Excellent Machine — even with a power supply failure, it still manages to get a message out (in plain English) attempting to explain the failure.