New 9800GT, computer won't power on

[phantomandy]

I'm not 100% sure what the problem is but here's my situation.

I have a PC that's been running fine until getting a new video card.

Upon installation of the new card I had trouble getting it to power on but it eventually came up. It ran fine (loaded drivers, rebooted, ran 3dMark06, played around a bit and was satisfied).

I clicked 'sleep' and it went down as usual then immediately clicked back on but didn't reload into windows, and ended up sitting at a black screen. All I could do was hard power off. Then it wouldn't power back on.

I checked and rechecked all connections, reseated the card, changed from the 6 pin power connector to two 4pin molex connectors using the included adapter. All a no go. Power was getting to the mobo (indicator lights on the Card reader were lighting up).

I removed the new card, put the old card back in and I was back in business.

I suspect the power supply but would like some input before shelling out the cash for a new one.

Here are the specs:

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Original machine:
Gigabyte GA-965P-S3 (rev 3.3) Mobo
2Gb (2 x 1Gb modules) DDR2-800 5-5-5-12 timing RAM
Gigabyte GV-NX76T256D-RH GeForce 7600GT PCIe x16 Silent PipeII Video
2 WD Caviar Caviar SE16 7200RPM 250Gb Hard drives (in RAID-0)
1 WD Caviar 500Gb 7200RPM hard drive (stand alone on secondary SATA)
2 Lite-On DVD Burners
Intel E6400 Intel Core2Duo 2.13Ghz CPU Conroe 65 Watts
Floppy, Card Reader, 2 120mm multi speed fans (on low speed)
450watt SmartPower 2.0 Antec PSU (came with the Sonatta II case)

Changes made:
Removed 7600GT video card

Added new 9800GT Video Card (BFG BFGE98512GTHE GeForce 9800 GT Passive Cooling 512MB 256-bit GDDR3 PCI Express 2.0 x16)

Added 2 x 1Gb GSkill DDR2-800 5-5-5-12 timing sticks of RAM

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The new memory is still in the machine, running fine after putting it through it's paces, but I've pulled the new video card and put the original back in. All's good with the old card, but as said earlier when the new card is in it won't power on.

Is this a PSU issue? If so, how many watts should I buy. I hope this build will last me a while. There is a possibility that I'll go to a Core2Quad before upgrading the Mobo so I guess I should get a power supply that will handle that potential future upgrade as well. Heck - if I have to buy a power supply I should probably plan for even further in the future and plan on supporting my build and the I7 cpus as well when I upgrade the mobo some day.

Thoughts on the problem - and if confirmed a PSU issue thoughts on a nice but price conscious PSU?

Thanks in advance for your input.

 

[phantomandy]

I should add - the OS is Windows 7 - although that's a non-issue since the core problem is inability to power on the box.

Thanks

 

[apache_lives]

nvidia products just dont do standby thats a rule

reset the cmos and reseat the ram and video card

 

[phantomandy]

I've reseated RAM and video - no joy.

I've also been running an Nvidia 7600GT Silent Pipe II (Gigabyte) since 2007 and never had a single problem with full sleep in Vista and Windows 7.

I do howeve suspect that the full sleep could be an issue with this card, but still wonder about the PSU since everything I've tried since the sleep incident has resulted in the inability to power on.

 

[phantomandy]

Still scratching my head.

Also wanted to add that the CMOS settings were reset during the initial troubleshooting with no effect.