HP/DEC/Compaq

Hello all, I have rescued an HP/Apollo 400 from my employer that was stored in less than ideal conditions. The hard drive was seized and would not spin up so as a last ditch effort I opened up the drive to break the spindle loose. The platters were covered in condensation so yeah that drive was dead.

Now I don't have the special HP-HIL keyboard so I can't interact in any way. But last night I came home and found it powered up even though the front panel switch was off. Ok strange enough. I pulled the plug and then later on went to inspect everything closer. Now there is no video output and the status LEDs on the front indicate "CPU board timer failed or missing" according to the service docs.

What exactly do they mean by CPU board timer? Do they mean the 40Mhz oscillator, real time clock, or maybe the power up timer that takes the CPU out of reset? HP was nice enough to put voltage test points on the board and all the voltages read good.

*Quick edit*

I was counting the service LED as part of the diagnostic LEDS. They are all lit meaning the CPU hasn't even accessed them. This thing might be destined for the trash.

astouffer wrote: Now I don't have the special HP-HIL keyboard so I can't interact in any way.

If the PROM is in HP/UX mode, you can connect a serial cable to the DB25 port at 9600 8N1, and send `R' like mad during powerup until you get output to the serial port. Then, you can make the use of serial console permanent, by going into the configuration mode with `C', and change the onboard serial port mode from `L'ocal to `R'emote, confirm, and power cycle.
There is a similar procedure if the PROM is in Domain mode, but I'm afraid it's been too long and I have forgotten it...

astouffer wrote: What exactly do they mean by CPU board timer? Do they mean the 40Mhz oscillator, real time clock, or maybe the power up timer that takes the CPU out of reset?

This is likely the battery powering the RTC. There is a CR2032 (or is it CR2025?) cell somewhere on the motherboard, near the back connectors, which likely needs to be replaced.

Thanks for the info about the serial console. Unfortunately my null modem cable won't fit because this Apollo has a female DB25 port. I tried replacing the battery but the board is still unresponsive Before I was getting video output but now nothing.