• Please review our updated Terms and Rules here

Building a powersupply for an IBM PS/1 2121

F

fernando3k

Member
Joined
May 10, 2011
Messages
10
Location
Argentina
Hello! I have an IBM PS/1 (model 2121). I have no way to power it up, since the supply is in the monitor and I havent got one.
Does anyone know the pinout for the power connector (there are two connectors with a monitor icon on the back, one standard 15 pin for the video signal, and another 15 pin looking like a joystick interface - two rows with 8 respectively 7 pins). Thanks!
 
Guess what? I'm looking for a PS/1 2011 CPU (same as 2121 but with a 286 inside instead of a 386 processor) to perform a dissection of it. I want to extract the DB15, memory slot, and riser card pinouts to make self-made parts to expand it.
 
nestor said:
Guess what? I'm looking for a PS/1 2011 CPU (same as 2121 but with a 286 inside instead of a 386 processor) to perform a dissection of it. I want to extract the DB15, memory slot, and riser card pinouts to make self-made parts to expand it.
Click to expand...
And I'm about to scrap a PS/1 monitor (039-001) but it only has the normal HD15 VGA connector; guess it's for a different model?
 
nestor said:
Guess what? I'm looking for a PS/1 2011 CPU (same as 2121 but with a 286 inside instead of a 386 processor) to perform a dissection of it. I want to extract the DB15, memory slot, and riser card pinouts to make self-made parts to expand it.
Click to expand...

I've got a PS/1 512K memory card somewhere, if you're interested.
 
MikeS said:
And I'm about to scrap a PS/1 monitor (039-001) but it only has the normal HD15 VGA connector; guess it's for a different model?
Click to expand...

The PS/1 models 2011 and 2121 had the CPU power supply inside the monitor. 2133 and later models have AT style power supplies.
 
I remember the voltage between two pins was over 30 volts, but I don't remember which ones.
 
I measured over 32 volts in two pins near in one side of the connector. You can find them easily because they are connected to the two big PCB traces. I have no idea what other pins do, they all measured 0.1 or 0.2 volts... the speaker sound is also sent through this connector.

This power feeds a vertical card that converts it to the lower voltages.
 
nestor said:
I measured over 32 volts in two pins near in one side of the connector. You can find them easily because they are connected to the two big PCB traces. I have no idea what other pins do, they all measured 0.1 or 0.2 volts... the speaker sound is also sent through this connector.

This power feeds a vertical card that converts it to the lower voltages.
Click to expand...
Excelent, I connected a power supply of old HP printer then the PC turn on and it tried boot. I connected positive to first pin (left - top) and negative to chassis. The power supply is 30 volts and 400 mha. I think is little amps.
Thank you very much.
 
I did a quick measures on a PS/1 2011:

With the hard drive plugged, the 32v rail from the monitor had a intensity of 0.7A. Without the hard drive, the intensity was 0.5A. So at least the 2011 model will run with a 1A power supply.
 
You must log in or register to reply here.
Back
Top