exxos's Atari, Amiga & retro forum

Happy New Year!

Can anyone tell me what type of security screw this power supply has? My friend is going to replace some capacitors so that I can get the full voltage needed to get my SMD-140 working properly. At first it was just the Spindle motor that was not working properly but that was fixed. However a different power supply was being used and bypassed the power supply board on the SF354 and the drive was working with no issues after the spindle motor was replaced.

This SF354 is not a single sided single density drive as the previous owner modified it by putting in the Epson SMD-140 when I bought it in 1990 which I did not know at the time. It is a 720K drive with the original SF354 power supply. When we plugged the power supply to the ports on the back of the SF354 it was having issues reading disks. So we need to check the power supply, but need to open it first. Does anyone know what size and what type I need to buy to open it?

4 mm is to big. A 5/32 socket can be squeezed in but not the right shape.

Please see the attached picture.


Thank you

Yeah, some sort of weird security screw to prevent users tampering with the PSU.

I'd suggest a pair of long nose pliers like one of these:


As it looks like some very non standard sort of screw head. I'd suggest that the wider nose pliers like the pair with a red handle are going to be better.

Yea the needle nose pliers I have are too big to fit in the 3.5mm space. Need to find a smaller size one. Thanks for the reply.

ftovar wrote: 04 Jan 2025 03:28 Yea the needle nose pliers I have are too big to fit in the 3.5mm space. Need to find a smaller size one. Thanks for the reply.

I'd suggest once you do get them out you replace them with normal screws, this whole thing of security screws drives me bonkers.