Originally Posted by Schoenfeld
The "easy" mod is here:
The "more complicated one" is here:
PGA CPUs don't really have heat issues if they're operated within specifications. Since the 5V rail of the Amiga is only controlled by ageing power supplies, you might want to check how precise the 5V rail is gegulated. Some PSUs deliver over 5.5V on that rail, which results in more heat. I already had to fight with this topic on Micromys V3, where the right mouse button would not work when the Amiga was operated with over-voltage. You'd be surprised how many PSUs deliver too-high voltage.
In any case, I would not expect the CPU to be the problem. Like I wrote a number of times (in other places), Commodore didn't know all the details about their own chipsets, and it's still a trial-and-error job to get a specific motherboard up to date. I could have designed the new accelerators in a way that they are as slow as the old Blizzard boards on chipmem access, but that would have been pointless if mods become necessary on other occasions, such as using higher-resolution and higher-colour screenmodes.
Thanks for the reply Jens. The easy mod is not needed as those components are already missing from my 1D4 board, but the more "complex" fix looks a bit beyond my electronics capabilities, I fear I'd end up damaging my board.
Could the issue be averted by adding cooling to Lisa then if hot Lisa shows the problem?