VAXStation 3100/76 that show all diags LED lit?

[MattisLind]

I have gotten a VAXStation 3100/76 that show all LEDs lit on the back.

Is there anything one can do or is it a dead parrot?

The 5V is there at least. But haven’t checked the rest as I don’t know the pinout.

 

[jplr]

I have a VaxStation 3100 model 38, which did develop the same symptoms.
It was the signal "power OK" which was going up too quickly. I just added an RC circuit and it seems to work fine now.
Good luck!

 

[MattisLind]

Thanks. I checked the PSU connector and was able to find all voltages OK. +5V, -5V, +12V and -12V. There were also an isolated 9V supply. But the remaining pin, which I assume to be the power good signal, was constantly low.

I guess this means not good. The green LED on the front doesn't come on.

I opened up the PSU but then decided that I have far too many other projects to deal with so if there is someone out there looking for a project here it is... The problem is that it is heavy, 12.4 kg so shipping will be costly.

Clean, nice shape otherwise, 32 Mbyte of memory (I think - 8 modules), two RZ24 and one RZ25 and SPX video (which are missing the standoffs). It is the fastest in the 3100 series at 7.6 VUPS.

 

[bladamson]

I am sure shipping to the US would be nuts, but I have a 3100 that has battery damage that I think got down into the vias, and I am not sure if I can fix it....

How much are you looking to get for it, not including shipping?

 

[g4ugm]

I am sure shipping to the US would be nuts, but I have a 3100 that has battery damage that I think got down into the vias, and I am not sure if I can fix it....

How much are you looking to get for it, not including shipping?

I don't think shipping would be "nuts", probably around $100 if a quote I got for shipping a prom programmer from uk to usa is anything to go by.

 

[jplr]

> I checked the PSU connector and was able to find all voltages OK. +5V, -5V, +12V and -12V. There were also an isolated 9V supply. But the remaining pin, which I assume to be the power good signal, was constantly low. I guess this means not good. The green LED on the front doesn't come on.

You could create a new DCOK signal from the 5v and some delay with RC circuit.

 

[MattisLind]

I don't think shipping would be "nuts", probably around $100 if a quote I got for shipping a prom programmer from uk to usa is anything to go by.

Swedish post wants 150 usd. Need quite a lot of packing material to get it unharmed to the us, even though the case is mostly sheet metal.

 

[Bob-O-Rama]

Thanks. I checked the PSU connector and was able to find all voltages OK. +5V, -5V, +12V and -12V. There were also an isolated 9V supply. But the remaining pin, which I assume to be the power good signal, was constantly low.

If you are pretty certain the supply is working, it may be worth just disconnecting ( removing it from the female header temporarily ) the DC-OK lead and manually connecting the main board side pin ( through a pull-up resistor ) to +5v and see if it wakes up. If it does, then you can at least know the issue is the monitor circuit in the PSU and see if the system works. Its not hard to do and won't really permanently modify the system - that might also gin up the ability to sell / gift it.

 

[bladamson]

He's going to ship it to me when he's back from vacation.

I've generated the power sequencing signals for a qbus PDP-11 with an esp8266 module in the past. I shall try the same thing for this one when it gets here, assuming the PSU out of my battery-eaten straight-3100 isn't a direct swap.

 

[MattisLind]

I think it is great that bladamson takes care of this machine. I have far too many projects that I need to attend to and yet another VAXstation is not so interesting to me so I hope it will get a good life in the US.