That's it, Motorolin' did the PSU mod.
No offense,But how on earth does the amiga get any cooling with that setup?? its circumvented the path on the psu to pull air and not to mention some of the vents on the tiny psu are blocked off by the edge of the original psu case??
There is a reason that big fan is in the 4000,it not only cools the psu but it pulls air across the motherboard. Btw a regular atx psu board can be fit in a stock psu case with just a few notches in the fan housing-I've been doing them for 10 years that way.