Step-down converter questions

I've always had european MSXes until some four years ago. During the first two years I encountered this two times:

I let my most used Japanese MSX have a european PSU built in and another one luckily had a european PSU when I bought it.
The remaining Japanese models are being switched off as much as possible as I don't want to run into melting step down converters ever again.

Its power is important indeed. This particular unit with "just" 50 Watt could not handle a turbo R with a filled slotexpander. It got hot as well with just the computer attached to it.
These step down converters are just wrong.
-Neo- has the best solution if you want to keep your original internal PSU. These things are scarse though.

that is because those "sealed" units don't let the hot air escape from it, so them are the worse...., a good unit needs vents in the bottom and the top, to get cool air from the bottom and let the hot air escapes up, as the hot always go up.

Others transformers aren't encapsulated in plastic, like the ones for old printers, it is the transformer core painted in black what you get, but the connections are sealed on the sides, those are better, but also bigger.

(-Neo-, I sent you a message.)

Yes you can use a simple transformer but keep in mind that the slightly higher frequency will affect the cor of the msx transformer. This is usually noticable through some strange noises coming out and the transformer will be slightly less efficient so just a little bit higher heat output. I have my msx running for hours sometimes and it still didn't blow up. Transforner doesn't overheat.