[SOLVED] 20-pin (19pin) PSU not working with my 20-pin motherboard ?

[sectio]

Hello there,

i have this problem. I got an oldie workstation from 2010s and want to install XIGMATEK NRP-PC702 700W ATX12V v2.3 PSU but when I connect it it doesn't work. It's a 20+4 Pin psu with the one pin missing from the 20 Pin connector part (I read tht it's normal with newr PSU's, and that they should work with comuters built after 2003). Yet when I connect the PSU ant turn the power on It doesn't work. I know the PSU is responsive because I tried to short out pins 15 and 16 and the fan turns on, so the PSU should't be dead. On the motherboard I have 20 pins and on the PSU I have the socket of 20 pins wit the -5V pin missing, but as far as my google knowledge goes it should still work, or am I missing something out?

Another thing is when I check my motherboard on cmd it saus that it's HP 0B40h and in google I found that this MB has 24pin connector.. False source?
Doe's anyone know what is going on here and if I'm possible to somehow run the PSU on my rig?

Thank you in advance!

Hardware specs:
HP Z200 workstration
PSU that I try to install XIGMATEK NRP-PC702
Motherboard (as stated in cmd) Hewlett-Packard 0B40h

I add pics of writings on my MB, the old PSU (white socket) and the new PSU (black socket)

https://ibb.co/s1Rxd04

old-psu-socket hosted at ImgBB

Image old-psu-socket hosted in ImgBB

ibb.co

https://ibb.co/mJ5kCgZ

socket

Image socket hosted in ImgBB

ibb.co

 

[kerberos_20]

is this your mainboard? FMB-0901

 

[kerberos_20]

ill just redirect you here

Power Supply requirements

I had to buy a Power Supply since recently purchased HP workstation didn't have PCI-E power molex. The new one couldn't power the motherboard so naturally I thought I bought a defective PS and returned it to get a better one. This one also doesn't work. I'm beginning to think the output of the...

forums.tomshardware.com

 

[sectio]

Yeah, that's the mobo. Bummer, that HP uses only their own PSU's, that's so inefficient. Don't have the energy or time to DIY the socket adapter to ATX, so will have to change the whole rig i suppose. Thank you for answering my question!