... (I hear that the daughtercard contains the processor.) ...

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It sure do. Be assured, for all future occasions, that the ... ah ... interesting 8500/9500/Quadra 800 case style has a charm of its own. Replacing battery or RAM is an exercise in almost complete demolition, sometimes literally as the models suffered from a strangely rapid embrittlement of the internal plastics. In the 8500/9500, the plastic PCI-card-retaining tangs—and the main power-switch tangs—snap off as you look at them. The chiefest requirement for removal of the MLB is to remove the daughter-card first, and to be sure that it is completely bottomed in its slot when you reassemble the Mac. Failing to bottom the card, which can take considerable force when the slot is in good condition, is equivalent to having no processor installed.

Despite the layout, it is also necessary to work around the installed daughter-card to do anything useful with the CUDA switch. It needs a long, thin, nonconducting rod and a good light. The whole point of pressing the CUDA switch, and holding it in for 40-odd seconds (assuming that your battery shows 3.4V or more when measured in-circut), is to signal to the system that the present hardware is what has to be taken account of. That cannot be done if the daughter-card is not yet installed.

de

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Hmm... I successfully removed the motherboard and hit the reset button (not sure if the computer needs to be on while I do that...) After putting the motherboard and daughter card back, and re-connecting all those messy wires, I turned the computer on again and it hummed to life (minus the start-up chimes... I removed the speaker since it was getting in the way.) Eager to test it with my monitor, I brought it downstairs and re-connected it to the power supply. Oddly, as soon as I started it up again, the computer clicked twice and failed. I removed the daughter card, and strangely, the computer started up as normal again. :?: :?: :?: I have no idea how a computer can start up without its processor... unless the processor wasn't in the daughter card, which isn't the case here. I hit the reset button again and the machine shut down. Then I started it up, and just like before, it started up without the processor. It failed to connect to the monitor though. After putting the daughter card back in, the computer once more failed to start up. It seems to be doing EXACTLY the opposite of what should happen. I have no idea what I'm going to do... perhaps I should pay the money to have it fixed by a professional computer repairmen, or ask our school's IT very nicely to help me. Thanks for the support, I really appreciate it. :b&w: