Graphics card/monitor problem

Hi. I'm not sure how to word my question, but here goes.

I'm running two 8800 GTS 512's in SLI with one monitor, and I believe my primary(?) card is dying. I'd like to test this by hooking my monitor to the secondary card, but my techniques to try and do so haven't worked yet. The reason I can't (even remotely easily) take out the primary card and move the secondary card into it's place is because I have a very tight watercooling setup that I'd have to ruin if I wanted to do so.

First, I turned my pc off. I removed the SLI adapter. I switched the monitor cable from the primary card to the secondary and unplugged the power from the primary card. I turned my pc on and was surprised by an extremely loud, constant beep. So I reverted all of these changes and everything works again.

Is there any way I can use only my secondary card? Still not sure what to ask. Maybe from reading what I've said previously you can assume what I'm asking.