Power Supply Popping and arcing on start up - need a replacement part number

[Russ45L]

Click to power on my Omen 45L Desktop and sometimes the PSU will make a pretty loud popping sound with an arcing flash inside the unit. Seems like a relay issue but I am just going to replace the PSU assuming I can find the correct part number. (HP makes it less than intuitive when attempting to find the part number.)

I know it is a 1200 Watt and I have not taken it out yet as I am hoping to keep my down time to a minimum.

Pretty sure these are just ATX 3 boards so do I really even have to use a HP PSU?

[NonSequitur777]

@Russ45L,

Welcome to our HP Community forum!

Yes, your 24-pin ATX power supply is a 1200-watt unit with p/n: N36304-001.

And you are correct that any quality ATX power supply would be compatible with your PC.

Personally, from a gamer's POV, I would consider this Corsair RM1200e, a fully modular 1200-watt ATX 3.1 & PCIe 5.1 rated compliant power supply: https://www.amazon.com/CORSAIR-RM1200e-Modular-Low-Noise-12V-2x6/dp/B0DXVPBJJ2/ref=sr_1_3?crid=1INUX....

Whatever you do, remember: do not 'budget-down' on your power supply.

Kind Regards,

NonSequitur777

[Russ129]

Curious why you would suggest a PSU for an ATX 3.1 and not the ATX 3.0 the mother board is originally designed for?  If I am not mistaken the 3.0 allows for a longer duration max (startup) load of up to 17ms where the 3.1 only allows up to 12ms?

From what I read: "The ArcticOC Intel RPL+Z790 23c2 motherboard is primarily used in HP Omen prebuilt systems and features the Intel Z790 chipset, which was launched around the same time as the ATX 3.0 specification in late 2022. Key indicators of this standard in compatible systems and components typically include the presence of the 12VHPWR connector (or the newer 12V-2x6 variant) on the power supply unit, which the ATX 3.0 spec introduced to handle the high, transient power demands of modern GPUs.

The ATX 3.1 standard is a more recent revision that refined some aspects of the 12VHPWR connector and power excursion handling, but motherboards with the Z790 chipset are generally aligned with the initial ATX 3.0 specification."

[NonSequitur777]

@Russ129,

My friend, that's a very good and insightful question -and you're absolutely right about the timing and intent behind the ATX 3.0 specification.

To clarify: the ATX 3.1 standard didn't fundamentally reduce PSU startup load tolerance -it refined transient response behavior and improved the 12V-2×6 connector reliability (the safer replacement for the original 12VHPWR plug).

Modern ATX 3.1 PSUs are backward-compatible with ATX 3.0 motherboards such as your Z790-based ArcticOC board. In fact, they're typically built on the same hardware platform with updated firmware and connector standards.

So, whilst your system was originally designed during the ATX 3.0 rollout, a 3.1-compliant unit will meet or exceed all ATX 3.0 electrical requirements, including transient load handling. For most quality brands (Corsair, Seasonic, ASUS, EVGA), the difference is largely a matter of certification revision -not capability.

In short:

ATX 3.1 = fully backward compatible with ATX 3.0
Same power-up and transient specs for real-world use
Improved connector safety and regulation precision

That's why I suggested the Corsair RM1200e -it's an ATX 3.1 PSU, but it functions perfectly in any ATX 3.0 platform while giving you the most up-to-date standards and protections available.

Kind Regards,

NonSequitur777

[Russ129]

Thank you for your very articulate response! I ended up ordering an ASUS TUF 1200w (military grade) it is a 3.0 but given the issues had nothing to do with the plugs melting etc (and it also has a 10 year warranty), I think it's my best bet for this now already older PC!

FYI I am the OP Russ45L but totally forgot that I already had an account from my prior Omen >.<

[NonSequitur777]

@Russ129,

The Asus power supply is superb -outstanding choice!

Kind Regards,

NonSequitur777

[Russ129]

Just wanted to post an update as I installed the ASUS TUF Gaming 1200W ATX 3.0 PSU and discovered that it is also 3.1 compatible. More than enough modular cables, it fit perfectly in the case though it is slightly shorter in length but it works flawlessly. 

I'm impressed with HP's chassis design they even have an adjustable PSU support plate.

Highly recommend the ASUS TUF Gaming PSU for anyone that plans to upgrade or replace their HP OMEN 45L Desktop PSU!

Thank you again to NonSequitur777 for the quick, accurate, and articulate responses to this thread! 

[NonSequitur777]

@Russ129,

Thank you for the Asus 1200-watt power supply endorsement -I am actually working on a new gaming platform needing a high-capacity power supply, and truth be told, this PSU was on my shortlist!

Kind Regards,

NonSequitur777