PSAL wiring guide

[zetor2000]

Hi!

I received a rather old shelf. It has 10 card spaces. It has a metal box with 3 connectors on the back, 2 of them are +48V and 0V, and the third is labelled "PSAL". I connected the +48V and 0V to a UPS, and the CPU board attached to the cabinet shows signs of life thru a serial console, but the boot does not occur.
The only thing it shows is that the bios version is built before Christ, and there is a "PSAL ALARM, Waiting for blahblahblah"... so there is a problem with the power.
How or where do i need to attach the psal wire?

I found documents from rel 5.1, but this rack was not mentioned... i think it is ~20years old, or more, but i could use it as a service cabinet.

[vad]

Connectors marked +48 and 0? Or -48V?
If you connect PSAL connectors to -48V - your CPU can works.

[zetor2000]

Thank you, Vad!
I suppose the label shows 48V / 0V / PSAL, the polarity of the 48V is unknowwn. I do not remember. I have to check it, if i get back to my site.
I can only remember, if i made a wrong connection, my power sdupply's circuit breaker was shut down the power.

[morio]

loop -48v with PSAL.. it works