Help me troubleshoot....Please!!!

[Tempest]

How it started:
Have old POS desktop with AGP slot. Also have a Dell 30" which i've been waiting to buy new pc to use it with. Received gift card for Best Buy (hate that place) so i thought i'd buy a modern AGP card for my old pc to hold me over until i can buy the new pc.

ISSUE:
Best Buy AGP card selection sucks. So i purchased an ATI 2600XT agp. Installed it, booted up, installed drivers....everything going good. Turned pc off to move it...turn back on, and no post. Swapped out card with old video card....it posts. Put new card back in, it posts! Shut down, turn back on, no post. So unless i want to turn it on once and leave it running forever, it just doesn't seem it's gonna work.

CAUSE:
my theory is my old mother board (which only has a 4x agp slot) is not handling the power the card is pulling? But is strange 'cause this 2600xt has a power connector on it (which i DID connect to psu) My PSU is newer...trupower 550...Antec i think?

RESOLUTION:
This is where i need help....i spent a long time swapping out the old and new and no matter what i did, it either would only post once, or not post at all. So i'm convinced the 2600xt won't work on my board...so i'm gonna return it.

Should i even bother to try another card? They have a Geforce 7600GS agp.....my only hope is that it wouldn't put the same strain on the motherboard that the 2600xt did. (if that's even the cause)

What should i do?

 

[CoolHotCold]

did you uninstall the drivers for the old Geforce card?

 

[Thund3rb1rd]

kinda off topic but, will your gift card work online? probably a little better selection

 

[Lamont Cranston]

sounds like maybe your card isnt getting seated just right, sometimes when you put the screw in the back to hold the card in it will pull the opposite end of the card out a little bit and that might be causing your problem.

If your computer will boot with it in at all its not "too much" card for your computer.

 

[Tempest]

did you uninstall the drivers for the old Geforce card?

Drivers play no factor here if the pc won't even post. But i think i have discovered my problem, see: http://www.neoseeker.com/Hardware/faqs/kb/10,63.html

so apparently, old motherboards use 1.5v for the agp slot. I confirmed that my board does in fact only support 1.5v. So, the problem i now have is finding a modern agp card that will support that voltage. I don't have to have the best one out there, the only requirement i have is that it supports dual-link dvi so that i can run the 2560 x 1600 resolution of my 30" monitor.

Anybody know any agp cards out there that will support the agp 1.5 voltage?