[Info-vax] Personal Workstation 433 rescue guidance

[Simon Clubley]

On 2021-06-15, Larkin Nickle <lhnickle at gmail.com> wrote:
> On Tuesday, June 15, 2021 at 11:18:52 AM UTC-4, Crabs wrote:
>> On Monday, June 14, 2021 at 9:36:53 AM UTC-7, Larkin Nickle wrote: 
>> > I?ve acquired a Personal Workstation 433, but I can?t get it to work. When powered on, the green light on the front turns on and I can hear the disk spin up, but there?s no serial or graphical output. The power light on the motherboard turns on but none of the diagnostic lights do. If the CD-ROM drive is connected to IDE, it shows no signs of life, but if connected to power only then it blinks, ejects, etc. just fine. The machine doesn?t even beep with all RAM removed. I?ve reseated just about everything and have also checked the PSU?s voltages and they?re all good. Any suggestions?
>> There are 8 small leds on the upper motherboard between the processor and the ram, during the boot process they flash in a particular sequence. 
>> Somewhere there is documentation that will tell you what each combination means, but if they aren't flashing at all during the boot then the upper 
>> motherboard, or something on it has failed. 
>> Check to see if the right RAM is installed, it must be in identical pairs, 66MHz or 100MHz (133MHz won't work) ECC CL3 Synch 3.3v 168-Pin DIMM Memory, 
>> up to 1.5gb total. 
>> 
>> 'Crabs
> Those lights don't turn on at all. That's what I meant by "diagnostic lights" in the OP. The RAM does seem to be correct, and the system is supposed to beep if not as far as I'm aware.

Have you tried powering up with all attached devices disconnected
just in case something is pulling down the power supply lines ?

If that doesn't work try powering up with the RAM _also_ removed in
addition to the optional devices to see if you get the error lights.

When you are testing the PSU voltages are you doing it while the
PSU is connected to the system ? (IOW, when the PSU is under load ?)

If you can trace the power lines on the motherboard and can _safely_
probe them, have you tried probing the power lines on the motherboard
itself ?

I'm assuming the system would at least show some life if the backup
battery was dead, but have you checked the backup battery anyway ?

Simon.

-- 
Simon Clubley, clubley at remove_me.eisner.decus.org-Earth.UFP
Walking destinations on a map are further away than they appear.