I clipped it to the socket along with the current fan, as I have done this with the fat ps2 fan connections many times before (shared fan power sources i mean) without any problems. It even powerd on without any trouble for a breif moment, but as soon as I turned it off after testing it, it enver came back on nor did it give me a red light anymore.
While it was drawing the power out of the system it most likely blew a fuse, double check all your fuses, normally drawing out too much power from any power source in the ps2, will blow a fuse, and there are around 15 fuses, each fuse for a specific part in the system. So make sure they are all working once more, if there is no luck, then it can only possibly be a dead board.
And as for the older system, i cant remember exactly, but i think it had a dc 9v/12v fan, which required more current then the slimline, thats why it didnt work out the way you wanted on the slimline. Were you attaching the fan to cool the system down?
Yes, It was getting warmer than usual when fighting the final boss in Fatal Frame 3. I never had the unit get that hot before, and it only seemed to get that hot when at that part in the game. Tekken 5 only caused the unit to get "warm", and it is a very graphically impressive game. I do know that the last part of Fatal Frame 3 requires a lot of streaming audio, shaders, and it works every feature of the ps2 a great deal during the boss fight. I figured that a fan would certainly be needed. Now, where would the closest related fuse on the board be I wonder. Most of the components near the fan connector do not resemble a small fuse like the rest of the board. I need a diagram that shows the top-side fuses of the board as well, where can I get that?
I dont think that there are any fuses on the top side of a slimline board, if your sure that all the fuses on one side are working, then it is only possibly 3 things, a blown motherboard, a faulty ac adapter, or the ribbon cable that connects to the power/reset button is damaged/not plugged in properly, or the power/eject button board is damaged.
I will have to retest the fuses when I get a hold of my v-meter again. This time I will be sure to test them properly now that I understand all of the v-meter settings. I'll post back later today/night or tomorrow.