17 Nov
2022
17 Nov
'22
12:33 a.m.
On 15/11/2022 23:22, Peter Coghlan via cctalk wrote:
My experience with a H7822 is that when all the
diagnostic LEDs stay lit,
DC OK is probably not getting asserted so the power supply might still
not be working 100% correctly. In the H7822, DC OK seems to be the
purple lead and high (something around 4V-5V) means asserted.
Thanks, but sadly in this case it's not such a simple diagnosis. I had a
spare 15 mins tonight so I powered it up and checked (DC OK is indeed
the purple lead). DC OK is sitting at 5.13V so the problem lies elsewhere.
I do have another H7822 in a MicroVAX 3100-80 (iirc, could be -40) and
that one doesn't start either. I've done nothing with that one at all
since it has a Dallas chip and so didn't need any remedial work. At some
point I'll get back to these and spend some time trying to get them
going. But I need to do some work on a Rainbow and some uV3600 PSUs
first before I get back to working through uVAX/VS 3100 PSUs (I also
have 5 H7821 PSUs there, so I expect that I'll be back ...).
Antonio
--
Antonio Carlini
antonio(a)acarlini.com