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Faulty MicroVAX II

SteveG

Experienced Member
Joined
Sep 30, 2020
Messages
135
Location
Millmeece Near Stafford UK
After getting the power supply repaired on this Micro VAX II unfortunately the computer appears to be faulty.

The indicator on the rear control panel displays “F”. The four red LED’S on the back of the processor board stay solid red.

I don’t get any activity on the serial consul RS232 connection either.

Can anybody suggest any simple diagnostic checks. NB. My electronics skills are minimal !
 

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daver2

Veteran Member
Joined
Jun 19, 2012
Messages
6,786
Location
UK - Worcester
I have various bits of PDP / VAX to give away to a good home...

Can you let me know exactly what you have? Next time I am at work I will see if there are bits for you.

Dave
 

tradde

Veteran Member
Joined
Apr 30, 2003
Messages
1,262
Location
Katy, Tx
A Google of "Micro Vax II error code f" returned:

F Waiting for DCOK
1. KA630-A module (does not recognize DC OK assertion)
2. Power Supply (negating DC OK on bus)
3. A Q22-Bus device (negating DC OK on bus)
4. Backplane (DC OK shorted to another signal)
5. Power Supply Cable (defective or not properly connected)
 

SteveG

Experienced Member
Joined
Sep 30, 2020
Messages
135
Location
Millmeece Near Stafford UK
Hello Dave,

this what I have:-



I guess I will need to test my configuration with a new processor board first.
 

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tradde

Veteran Member
Joined
Apr 30, 2003
Messages
1,262
Location
Katy, Tx
What other boards are in it? Was it working for you before at some time? I know very little about micro Vaxen. I did not find anything about the CPU board lights.
 

SteveG

Experienced Member
Joined
Sep 30, 2020
Messages
135
Location
Millmeece Near Stafford UK
There are 5 boards in the first expansion box and a connector board linking to the second expansion box.

The first box has processor board plus
1 x GA1727
1 x GA3858
1 x M7186 8Kbyte static RAM for expanded CMR01-AA
1 x M7516 DELQA Ethernet interface.
 

Alegend

Member
Joined
Jun 13, 2017
Messages
47
Location
Israel
Except for the DELQA, I do not recognize anything in your board list as part of a MicroVAX II.

Remove all Qbus boards including the enclosure interconnect.
Make sure you have only the CPU installed, at the correct position. It should be a M7606. Power the thing up and see what LED code you get.


A repaired power supply does not necessarily mean one with a working DCOK signal - the power supply may still be faulty in that respect.


-Alon.

There are 5 boards in the first expansion box and a connector board linking to the second expansion box.

The first box has processor board plus
1 x GA1727
1 x GA3858
1 x M7186 8Kbyte static RAM for expanded CMR01-AA
1 x M7516 DELQA Ethernet interface.
 

SteveG

Experienced Member
Joined
Sep 30, 2020
Messages
135
Location
Millmeece Near Stafford UK
Progress !
I have parked this VAX for a while but I am now back on the case.
By removing the spare cards and moving the processor to its top slot the test indicator now stops at test “C” rather than test “F”.
Currently I have fitted into the chassis one processor card and 2 memory cards and nothing else.

I fear the processor may be faulty if it stops at test “C”.

Any ideas as to what I need to do to confirm this?
 

kb811

Experienced Member
Joined
Sep 10, 2020
Messages
55
Progress !
I have parked this VAX for a while but I am now back on the case.
By removing the spare cards and moving the processor to its top slot the test indicator now stops at test “C” rather than test “F”.
Currently I have fitted into the chassis one processor card and 2 memory cards and nothing else.

I fear the processor may be faulty if it stops at test “C”.

Any ideas as to what I need to do to confirm this?
Error codes:
https://support.hpe.com/hpesc/public/docDisplay?docId=c01608433&docLocale=en_US

BA123 enclosure/backplane? Not all QBUS backplanes are the same and not all cards can go into all slots. For example, see "1-10" and "1-11" in
http://www.bitsavers.org/www.comput...BAA-MN MicroVAX II 630QB Technical Manual.pdf
 

Alegend

Member
Joined
Jun 13, 2017
Messages
47
Location
Israel
The CPU is looking for RAM.
Try this setup with at least one memory board installed, don't forget the 50-pin flat cable interconnect from the CPU to the RAM board(s).

-Alon.


Progress !
I have parked this VAX for a while but I am now back on the case.
By removing the spare cards and moving the processor to its top slot the test indicator now stops at test “C” rather than test “F”.
Currently I have fitted into the chassis one processor card and 2 memory cards and nothing else.

I fear the processor may be faulty if it stops at test “C”.

Any ideas as to what I need to do to confirm this?
 

SteveG

Experienced Member
Joined
Sep 30, 2020
Messages
135
Location
Millmeece Near Stafford UK
I did have the 50 pin connector in place.
I have also tried the RAM boards the other way round I.e. 2,1and 1,2.
As you can see from the photos I still stop at “C”.
The processor LED’s are green red red off off as can be seen from the photo.
Any ideas apart from removing the RAM boards again and cleaning all contacts with contact cleaner ?

00710248-F366-4B26-A5D6-A807F3E7B43C.jpeg E867520F-6D29-423E-BE3A-A09AF2FCA75D.jpeg
 

Alegend

Member
Joined
Jun 13, 2017
Messages
47
Location
Israel
A faulty CPU still can't be ruled out.

One RAM card instead of two might help you perform quicker tests and maybe narrow down the fault.

The flat ribbon cable can be faulty, that is something I have seen in the past. Try one RAM card and you'll be able to test using the same cable but a different pair of connectors on it.

-Alon.

I did have the 50 pin connector in place.
I have also tried the RAM boards the other way round I.e. 2,1and 1,2.
As you can see from the photos I still stop at “C”.
The processor LED’s are green red red off off as can be seen from the photo.
Any ideas apart from removing the RAM boards again and cleaning all contacts with contact cleaner ?

 
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