I need a higher wattage psu, will this one work?

[LonesomeRanger0]

So I'm trying to take this desktop that I got for cheap and turn it into a low end gaming pc, and I have everything I need, I just need a slightly higher wattage power supply. now I looked online and as it turns out, hp has proprietary mobo power connectors in their systems. I looked for one that has that connector(s), and i found this:  

https://www.ebay.com/itm/195871755950?_skw=400W+POWER+SUPPLY+IN+A+HP+PC&itmmeta=01KC9ZE93Q7XC8MWT3Y4...

the mobo/psu combo in my system currently has a p7 pwrcmd connector, and two p4 connectors (one for cpu, the other for mobo, drives, fans etc.) the pwrcmd has 7 wires going out of it, one for each pin. the one I'm trying to get (see above) has 7 pins, but it only has 3 cables going out. does that matter? and will I be able to use this other one?

1st picture is of the pwrcmd cable, the 2nd is of the labels for each wire on the inside of the psu, 8th one being the far left black one and so on, going right.

pwrcmd cablepsu pwrcmd wire labels, 8th one being black

thanks in advance

[DGroves · Accepted solution]

yes the HP 400  (and 550) watt power supply is compatible with the sellers listed HP systems

you can use the 250-watt power supply (p/n: L08417-004/002) or, better still, a 400-watt power supply with p/n: 942332-001, (L04618-800) with one 6+2-pin PCIe power cable, and a 500-watt power supply, with p/n: L77487-003 (L89233-001), the latter being equipped with two 6+2-pin PCIe power cables.

this system uses a non ATX power supply where the power supply only has 12v DC out

the motherboard has the missing 3.3/5v circuits that take the power supplies 12v and regulate it down to 3,3/5v and some of the HP systems (or all?) have a 4 pin connector that is for the sata/HD power

https://h30434.www3.hp.com/t5/Desktop-Hardware-and-Upgrade-Questions/HP-Prodesk-G5-SFF-PSU-amp-GPU-U...