Unfortunately, my (brief) search did not locate a service manual, but this post included some photos:

https://www.eevblog.com/forum/chat/schematics-12805/

Sad to say none of them obviously show the power supply input.

 

Hi,
Comparative images.
E

 

Unfortunately, my (brief) search did not locate a service manual, but this post included some photos:

https://www.eevblog.com/forum/chat/schematics-12805/

Sad to say none of them obviously show the power supply input.

Tremendous, thanks. I see it uses a Z80! My word. That's the first processor's assembly language I ever learned.

 

Just clarify, are you suggesting a coaxial power connector would expose live contacts?

It's a very common choice for 5-24VDC. The center female contact, which is V+ is not exposed. In fact, it's lead exposed that the male mini-DIN that female connector accepts. There are a lot of options. These pigtailed panel mount jacks are nice because they are IP67 rated and of course there are a lot of options for the male connectors.

View attachment 259212View attachment 259213​

I am not sure you were talking about the coaxial connecter, so just making sure I understand.

Hi
was referring to the OP picture, that looks like a standard 3 pin DIN Skt, that means the live end is the standard 3 pin DIN plug, with the pins such that a bit of metal can short out the pins,

The original UHUR tape recorder we had, had a , I think 4 pin Din socket as the power in,
was not unusual to
a) get some one plug a PSU into a mic input , or at least try to and bend pins
b) have a blown charger with some one having shorted out the pins ..

 

Hi
was referring to the OP picture, that looks like a standard 3 pin DIN Skt, that means the live end is the standard 3 pin DIN plug, with the pins such that a bit of metal can short out the pins,

The original UHUR tape recorder we had, had a , I think 4 pin Din socket as the power in,
was not unusual to
a) get some one plug a PSU into a mic input , or at least try to and bend pins
b) have a blown charger with some one having shorted out the pins ..

Gotcha.

As an aside, the designers of DMX (stage lighting control protocol) didn’t do anyone a favour by choosing a 3-pin XLR connector as their standard in the environment of a theatre when microphone cables are going to be using the same connector for what they were designed to do.

This isn’t as bad, though, as using something like a 3.5mm phone plug to supply DC power as was done in the past where other consumer products had 3.5mm phone inputs.

My rule is, don’t put signals on connectors that aren’t the same as what someone would expect to be there, and certainly don’t put signals that would damage the expected device, or do damage if plugged into by it.

 

After tipping the house upside down the original Cheetah power supply has been located and both PSU and vintage keyboard work! Crisis averted. Thanks to everyone for help and advice