Replacing graphics card with an RTX 4090

[Unmensch]

I have tried replacing my rtx3080 with a 4090, but i get no display and as soon as i boot up the motherboard is making 3 long beeps, followed by 3 short ones. After doing some research im suspecting that the power supply is not good enough to power up the card, as other users who fixed this issue used a 1200w PSU to do so. Im looking for a PSU that would fit inside the 45L desktop case, alternatively a cheaper solution to my problem would be greatly appreciated.

[NonSequitur777]

@Unmensch,

Welcome to our HP community forum!

You are correct: your OMEN By HP 45L Gaming Desktop PC GT22-0000i as fitted with an RTX 4090 requires a beefier power supply than the 800-watt power supply you got (or so I assume), as this Omen User indicated:

Link: Upgrade of an HP 45L 800->1200W Power Supply & RTX Founders 4090 Graphics Card : r/HPOmen (reddit.co....

This 1200-watt power supply (assuming you can order it in Germany to begin with) is hugely expensive, and I wonder if a quality ATX power supply* would suffice, like a Corsair RM1000x, such as this purchase example via Amazon-Germany: Corsair RM1000x 80 PLUS Gold Fully Modular 1000 W ATX Power Supply , EU - Black: Amazon.de: PC & Vid... or the Corsair RM1200x: Corsair RM1200x Shift Fully Modular ATX Power Supply - Modular Side Interface - ATX 3.0 & PCIe 5.0 C....

* Unless it is the case that your Omen does not have a 24-pin ATX-power enabled motherboard, then you'll have to go with HP's proprietary power supply magic.

You would have to make sure that the Corsair power supply's dimensions (LxWxH) are a fit for your PC.

Kind Regards,

NonSequitur777