Corsair TX750W PSU Won't Work in HP e9150t - Why?

I was wondering - did you need to do anything special to install the 850W Corsair in your m9650f? Reason I ask, I'm trying to install a 750W Corsair in my e9150t system. In summary, installing new Corsair 750W power supply in new HP PC causes PC to fail to POST. I've built several PC's over the years, never hit this type of brick wall.

The details:

1. We purchased this computer HP e9150t

2. The HP PC has been running for several days as burn in, working fine.
3. So that we had enough overhead for larger video card (video card was not yet installed - everything was stock on the HP except for the PSU) we were looking to swap out the 460W power supply with this 750W power supply, CMPSU-750TX. We have this power supply in our current Dell PC, works fine. We just pulled it to install in the new PC.
4. After the Corsair PS is connected to the HP the HP fails to boot. The cooling fan on back plate spins up, the power indicators on the PC light up but no other noticable progress - fails to POST.
5. To eliminate any chance of one of the peripherals causing a problem we connected PS to only the 24 and 4 pin connectors on motherboard and booted, no change in response. The attached monitor didn't even acknowledge any signal from PC.
6. To confirm that HP didn't suddenly hit the wall and crap out on us during the PS upgrade we connected the original PS to the HP (only 24 and 4 pin connectors), unit hit POST (monitor registered signal).
7. Connected Corsair back to HP, same non-responsiveness.
8. Connected original HP PS and assembled unit, works fine.
9. Put Corsair back into Dell, Dell works fine.
10. HP just doesn't seem to like the Corsair 750TX power supply

So, what I'm trying to understand is why a "better" PS (better wattage) would fail to boot up in the new HP. Any suggestions or anyone have any idea on what may be causing the conflict? PS - we did not install the new video card yet, everything in HP was stock other than the swap out of the power supply.

the HP might have some weird pin layout on the 24pin connector that isn't ATX compliant...

HP and Dell PC are not using universal hardware. Too bad for you, you got the shoice of buying another Motherboard, or another power supply compliant with HP hardware.

Personally, I will got with another motherboard.

No chance of shorting out anything with loose screw. I swapped the HP and Corsair PSU out 3 different times just to make sure ti wasn't something obvious. Power up right away with the original HP PSU, went into a coma with the Corsair. Not aware of any unusual pinouts with the HP, but at this point it's the only thing that makes sense. However, I've seen others swap out the PSU on the HP so doesn't seem to be proprietary. Definitely has me scratching my head on this. I've sent emails to Corsair and HP to see if either of their tech support can provide any insight as well.

If HP were using a custom pinout on the 24pin ATX, they'd have the common sense to move the blanking pins (or whatever they're called if they're not blank)

Is the Dell an I7 system ?
I've read about your issue with Corsairs and Dell I7 systems, seems to be a voltage compatibility issue.

Compare the power on the 5 volt rail of the two psu's. Is it higher on the original power supply or the new Corsair psu?

There is a very remote possibility that too much power is being delivered to the motherboard. I am not positive about it. I am growing old disgracefully and I forget stuff.

Thanks for the folow-up. I did a quick search and didn't find anything on the HP Forums on using Google that addressed this. Do you have a link to one of the HP forum threads?

Certainly exhibiting the same type of circumstances (I didn't have speakers attached so can't confirm beeps), but sounds similar to the other actions I was seeing. Thanks for your response on this. It will be interesting to see what Corsair has to say on this. Hard to believe that HP wouldn't support larger power supply units, especially on a system that supports dual video cards (power hungry).

I bought a different power supply, 450W, all worked fine.

Hey there JohnnyLucky! Haven't run across you in a while.

I have heard reports over the years of otherwise perfectly good power supplies and motherboards that just don't like each other some unknown reason. I'm wondering if thats what we are looking at here.

Corsair.