Replacing IIsi Power Supply PSU with a new alternative

[ymk]

I have been using a Wyse 991438-01 PSU together with a 12V DC adapter. Soft power works with an added transistor, however shutting down the machine results in a restart, so I added an off button. The whole system runs at about 10W, so there's no need for a fan.

I didn't buy mine here, but they're going for $10: https://www.ebay.com/itm/334659735570

 

[zigzagjoe]

I have been using a Wyse 991438-01 PSU together with a 12V DC adapter. Soft power works with an added transistor, however shutting down the machine results in a restart, so I added an off button. The whole system runs at about 10W, so there's no need for a fan.

I didn't buy mine here, but they're going for $10: https://www.ebay.com/itm/334659735570

While that's a clever re-use, it looks like those power boards are likely to be the better part of two decades old. You probably want to recap them first given they date to the days of the capacitor plague.

 

[ymk]

You probably want to recap them first given they date to the days of the capacitor plague.

That's sound advice. Mine was NOS and isn't showing signs of trouble, but I'll get around to recapping it.

It's not a difficult or expensive job.

 

[f17]

I have been using a Wyse 991438-01 PSU together with a 12V DC adapter. Soft power works with an added transistor, however shutting down the machine results in a restart, so I added an off button. The whole system runs at about 10W, so there's no need for a fan.

I didn't buy mine here, but they're going for $10: https://www.ebay.com/itm/334659735570

This is clever and fits nicely inside the case. I don't see any cap plague there. There are a couple surface mounted electrolytics that might have leaked, but the through hole electrolytics don't appear to have the plague, else they'd be venting out the top.