But the machine worked properly before with the PSU connected to the Mediator, wouldn't that indicate that the fault is something else? I've had to install the Indivision a few times since it had the tendency to jump off if I moved the Amiga, and I always feared that the force inflicted on the mobo would break something.
That's a possibility, although you could have just been lucky that it was working with less juice before.
Mine was worked before I spliced the third connector but it was flaky at the best of times and would refuse to boot quite often or just lock up for no apparent reason too, which is why I performed the modification.
It's worth a shot.
