I just bought a Seasonic Super Silencer 460W power supply to replace the generic 300W one I've been using for the past year. My reason for replacing it was to reduce the noise.

I plugged in the new one, hit the switch, my subwoofer goes "bump" and the case fan twitches then nothing. Subsequent presses of the power button do nothing. If I unplug the PSU and flip the 1/0 switch a few times (recommended by seasonic to reset the protection circuits) then push the power button it will do the same thing - bump, twitch, nothing.

Hook up my old PSU again, everything's fine, works perfectly.

So I opened an RMA with the manufacturer only to find out they will only pay half the shipping. Called the vendor, they will pay all of the shipping as long as they verify it is definitely defective.

Here's where it gets a little interesting...

If I unplug my graphics card (Radeon 9700PRO All-In-Wonder) from the PSU, the computer starts up and a little error message comes on the screen telling me I forgot to plug in the power for the video card (for those not familiar with the 9700 video card, it takes a regular floppy connector to supply additional power).

I started thinking "ok, the PSU has a defect that only shows itself with high powered components attached"... and I decided to test that theory by plugging in all the devices I could find... two CDroms, 2 serial ATA hard drives, 4 regular ATA hard drives. System boots fine with all of those attached.

I'm not sure if those extra devices are enough to equal the power consumption of the 9700 though... my guess is not... anyone know for sure?

so is the PSU defective or does it just have some incompatibility with my graphics card?

is the graphics card defective and the old PSU doesn't have a problem with it but the (more sophisticated) protection circuits in the new PSU do?

and how come batman doesn't dance anymore?

sounds like a messup in the cables... maybe u dont have ur connector to ur card on right or something odd like that... i doubt the PSU itself is defective.. or else your comp wouldnt work.... and all PSU's are compatible with everything basically.. if its an ATX power supply.. itll work with 99% of everything youve got

I double checked the plug and confirmed it's connected properly. The floppy power connector is keyed to prevent such mistakes anyways.

Try having the 9700 plugged in on that one single power cable line and nothing else plugged in on the molex connectors on the same line. The 9700 may be pulling a lot of juice from the floppy connector.

thanks for the suggestion =o) I gave it a shot and got the same result. So weird...

If you previous PSU worked fine then logic should point out that there is something wrong with the Seasonic PSU. I would recommend a RMA for a new one.

thanks for the advice, I appreciate it =o)

RMA for a new one or buy a known brand like ANTEC or ENERMAX

Have you tried Y connecting the card trough one of the HDD, if i remember right in the radeon how to they say to plug it using a splitter from the hard drive

http://www.trustedreviews.com/article.aspx?head=64&page=2279

chech out the seasonic. it's a good psu

wuddup kobalt. Yeah, I tried the little splitter that came with the card but it still did the same thing.

Also, I had a friend try the PSU in his computer last night. His is a p4 prescott with an intel mobo and radeon x700 using PCIexpress. He didn't have any problems whatsoever (unfortunately he declined my offer to sell it to him =o)

I emailed seasonic with basically a cut and paste from this post describing the problem. They just said "open an RMA". I replied asking them if I would have to pay the shipping for the RMA. (because there's no way I'm paying to ship from toronto to california - I'd rather just try to sell it on e-bay or something)

Edit March 10:

I gave my graphics card to a friend to try in his system. I was pretty surprised when he told me that he had the same problem I did. So something's wrong with my graphics card. Near as I can tell it's some defect that my old power supply doesn't mind, but the new PSU and my friends PSU don't like it. Maybe a broken wire or something. I've looked the card over but didn't see any problem. Removed, cleaned and remounted the heatsink, tried it with the fan unplugged. Nothing helps. I guess I should continue my investigation in the graphics forum =o)

Thanks all.