[xnopasaranx]

thanks for the tipps. seems like I am on the right track now, but still I am not quite sure how to proceed. To clock down the ACA, I believe I would have to swap the divider resistor? and probably the quartz as well? or is another divider enough?

On the weekend, I finally have some free time, so I can measure with my scope what is going on on the 5V rail. Pretty sure though, that my issues are not power related anymore.

I'll also test the chipmem without the ACA for an extended period of time.

Some additional results show, that the crash appears quicker than I thought when hammering the RAM with systest. One of the screenshots shows that the amiga already froze on the first cycle (Round 1.5). So that must have happened after 30mins or so already. Guessing that the memory access with games is usually not as thorough and that is why the problem appears a lot later in normal use.

@Daedalus do you think that swapping out the chipmem will yield better stability? and would it be a goog idea to put in sockets for the RAM chips? or is that a bad idea? I think I'd go for precision sockets anyway (the ones with a locking mechanism and a little lever), rather then the normal ones.

EDIT: Oh and I have of course tried to clean the contacts before installing the accelerator. I used a rubber eraser and isoprop alcohol after initial cleaning. But I will try to pull the card out a bit to see if the connection gets better and rule that out.