View Full Version : Weir SMM 1500 03 03 Power supply info....

May 18th, 2009, 07:18 AM
Hi Folks,

Well i got hold of a Weir SMM 1500 03 03 power supply to run my GEC 4070 Minicomputer on and although all looks well i get no output :(. I've connected all the sense wires to the correct outputs and loaded up the main supply outputs and still nothing.
Having taken the PSU apart i found a lead called 'Stop' going from the power in board to the main power supply board. If i disconnect this single connector the thing kicks into life and all output supply rails are correct :).
Anyone know if the INH1 and INH2 (Inhibit ?) need to be taken to a certain voltage (or grounded) for the supply to work properly? Is the PSU inhibited by default if nothing is connected to these terminals?
Any info would be much appreciated for this bit of gear. I believe that it probably works perfectly, it's just a case of working out how to make it do so.

Thanks very much for any help.

Alan. :)

May 21st, 2009, 01:25 AM
Just in case this rings any bells with anyone, this Power Supply originally came from an ICL DRS 6000 Minicomputer, although i must admit that i can't find much information on that either !! :(
Any info would be much appreciated (even the power up sequence mighht tell me how the supply is enabled).

Alan. :)

nige the hippy
May 21st, 2009, 03:20 AM
So it was you!

I'd be inclined to get a meter on the inhibit lines, If they're high, then they probably need pulling down, and vice versa, if you have no 5v supply out at all from anywhere, then they almost certainly need pulling down, to avoid the problem of having to "jump start" the DRS6000
If you do it through a 1k resistor, you're unlikely to damage anything.

There were heaps of (wet) chunky power supplies to be had at the radio rally on sunday, more amps than I'd ever need.

May 21st, 2009, 03:29 AM
Cheers Nige,

I was going to start pulling the unknown connections (including the 2 inhibit lines) to ground as that's all that is available (there are no standby outputs available).
One way or another i'll get it to fire up properly !

Thanks for the ideas.


Ross Thomas
August 26th, 2009, 08:41 AM
Hi there,

I used to work at Weir and after leaving had to deal with replacing an obsolete SMM1500 01 01 M28, back in 1999.

From some of my documentation from back then:

Power Good + Pin 1
Power Good - Pin 2
Power Fail + Pin 3
Power Fail - Pin 4
Inhibit 2 Pin 5
Fan Sensor Pin 6
Inhibit 1 Pin 7
Current Share Pin 8
5V +ve remote sense Pin 9
5V -ve remote sense Pin 10

All on the Molex connector.

See attached diagram.

Also helpful would be the Weir SMM/SMS 1500 Operating Instructions, Issue 1 - Jan 92, if you can get hold of them.

I'll try and dig up more details - I'm not sure where I have archived them.

August 27th, 2009, 04:10 AM
Hi Ross,

Thanks very much for the info. I cannot pick up attachments from the thread so could you PM me and i'll give you my e-mail address to send stuff to ( if you don't mind ?).
I belive that there is an electronics problem, so a circuit diagram would be very helpfull (electronics is a hobby so no problem with fault finding ;)).


September 8th, 2015, 02:45 AM
Hello Thomas!
I ask you to send the power supply circuit SSM1500. I have been repairing the power supply for themselves.