>- Some of the old AC-DC transformer blocks are dying or horribly inefficient anyways. Most of them are outside of the machine and can be replaced with readily available modern equivalents, so this one is extremely easy.
Except the commodore ones that fry the computer when they stop working.
I believe the Commodore 64 power supply I am using I ordered from c64psu.com. I did not evaluate the quality in any way, but years down the line it hasn't failed me. So, at least working replacements are available, and while they're not necessarily cheap, it's probably worth it considering you're definitely right about the fact that the Commodore ones tend to fail in pretty ugly ways.
Except the commodore ones that fry the computer when they stop working.