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Definitive List of Model II Operating Systems

I wasn't able to find a datasheet for the 3482 when I did a low-effort googling for it a few days ago. I seem to recall that the 74AA533 was a high drive strength latch.

I think that blindly swapping parts without diagnosing an actual failure first is more likely to burn more things out than to solve any problems. You need to diagnose the specific issue before changing anything. Swapping around boards, jumpers and parts without knowing what's even failing is probably just going to dig you deeper into the hole.
 
That's what I am trying to get done with the diags disk.

At least get me to the section having problems. Plus only having an DVM and no way to get to specific parts of the board makes it more difficult.

Try probing a chip next to the backplane connector and you will see what I mean. Voltages seem to be good at least where I can test them and I mean only the 5 volts. Continuity tests can only tell you so much. If pin 3 goes to pin 5 as it should then we are ok? Maybe or maybe not does the input from pin 5 give the output it should? Have no idea.

Having an O'scope around and having an extender board would make it simple. I am sure almost everyone here has one I do not. So if I take shots in the dark and try to guess where the fault is then so be it. I guess I will fall into that deep hole I am digging!

And yes Mark you are correct I couldn't find anything about that latch either. I hate having to troubleshoot this way.
 
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I'd design the extender card for you (and me) if I had a source for the connectors!

I haven't tried it yet, but last time I looked at my 6000, which is presently sitting in my kitchen with the top cover off (the joy of being single!), it looked like it might be easy to take off the top of the cage sheet metal to get access to at least the top of the 68k card. All of the other cards would still be buried, but having access to the top of the 68k card might help you a lot.

On my 6000, the top cover came off with the monitor and front panel staying in place. On my 12, the cover had to come off along with the monitor and front panel. I haven't studied them carefully enough yet to see if that's due to a production variation, screws left out by a previous owner, or ???.
 
mark yes my 6000 is a single piece as is yours. The front and back are screwed together. Even the service manual says it's in 2 pieces. The single piece unit must be a late change.

Yeah having the top of the unit off and the top of the card cage removed would help. But would want an O'scope to probe around. My logic probe is fried so may have to look into replacing it.

Thanks for the tip
 
FYI I have some updates, but it looks like I can no longer edit this posting, so I will probably continue to enhance this list on my own site going forward.
 
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