Compatability of 4Pin connector (P3 : PWRCPU) with Standard ATX 4Pin

[Zorono]

Hey there,
please is (P3: PWRCPU) 4 pin connector compatible with Standard ATX Power supply's 4 Pin connector  ?? I am trying to upgrade my Computer's Power supply to a standard ATX PSU 600W (300W+ HP Proprietary PSUs are very very rare in Egypt) to use my GPU which requires almost 175W, but I can't figure out if P3 Connector is compatible or not with Standard 4 Pin Connector... i am planning to use COMeap's 24 Pin to 6 Pin ATX Power Adapter Cable for the  P2 and P1 Connectors. any suggestion ??

[NonSequitur777 · Accepted solution]

@Zorono,

Welcome to our HP Community forum!

If you are going to use the COMeap ATX power adapter, then you are set.  The 4+4-pin CPU power from an industry standard ATX power supply is compatible with your motherboard: this power cable is designed to 'split': you'll end up having two 4-pin CPU power cable connectors, of which one of them will fit into your motherboard's "P3" power connector.

Kind Regards,

NonSequitur777

[Zorono]

@NonSequitur777

Additional question: Please should i connect both P3(PWRCPU)  and P1(PWR) at the same time to the 4-pin connectors or only one of them (I need to make sure to avoid burning my Motherboard) ??

[NonSequitur777]

@Zorono,

You know what, somehow, I overlooked/bypassed the "G3" designation. As it is, there are currently no ATX power adapters compatible with the HP EliteDesk 800 G3 Tower available.  There are ATX power adapters available for the G1 and G2, but not the G3...

Sorry: back to the drawing board, so to speak.  The best compatible power supply for an HP EliteDesk 800 G3 TWR is a 500-watt power supply, with HP p/n: 913290-001 / 901759-003 / 901759-013.

Kind Regards,

NonSequitur777

[Zorono]

@NonSequitur777

please, can anyone tell me whether PWR Meter Pin on the 7 Pin header (P2) Is Analog or Digital and please what  is the standard value of PWR ID pin since standard ATX PSUs doesn't provide such pins

Thanks in advance.

[NonSequitur777]

@Zorono,

Unfortunately, HP hasn't published much on their proprietary power supply (P2) wiring schemes.

Based on known HP proprietary power wiring schemes and the wire colors, here’s a likely P2 pinout interpretation:

Notes & Verification Steps:

1. Power Meter (Purple): HP often uses a 12V Power Meter wire, which provides an analog voltage proportional to system power draw.
2. PSU ID (Gray): HP uses a resistor (e.g., 383kΩ to 12V for 180W units) to let the motherboard identify the PSU wattage.
3. PS_ON (Green): Standard ATX-style function—grounding it turns the PSU fully on.
4. White & Red/White: These are the least standard; white might be 5V Standby, while red/white could be a power sense or additional control wire.
5. Black Wires: Standard Ground (GND) connections.

This is the best I can do for you.  Let me just say that trying to figure out how to interpret HP wiring is fraud with challenges.

Kind Regards,

NonSequitur777