"upgrade" potentially problematic C-64 PSU

I have a “repairable” C-64 power supply that I’d like to use for my Midibox SID, but I would like to replace the internal transistor with a regulator…I would hate for the supply to fail and take my Midibox SID with it. I remember in the past seeing a schematic for doing this. Or is there a better way?

Thanks,

Tom

If it is a “repairable” one like mine, a big black box with vents, it already has a 5v regulator with a massive heatsink.

Open it up and have a look.