As I was testing the new switch on my second AX-990 (with the cover removed) I happened to touch the heatsink and was surprised to find it was very hot.
It's a piece of hardware literally designed to absorb and re-radiate heat, so perhaps I shouldn't have been too shocked at this.
But it was very hot — almost untouchably so.
That got me thinking: is it possible to replace the linear regulators with a modern equivalent that emits less heat?
After all less heat is better, right?
And electricity turned into heat is basically wasted energy.
One problem that's been apparent on both my AX-990s was the incredibly poor video quality.
Colours would be distorted and sometimes the TV would lose the video signal entirely.
The culprit is the toggle switch on the rear that changes between MSX and Sega modes.
Often just touching it lightly was enough to make the video signal dance and flicker.
With only a small amount of work this can be fixed and perfect composite video is the result!