Dimension 4550 Power Supply - PS-5251-2DF

Something like the following?

http://www.911forpcs.com/dedi45posush.html

Or this forum post.

https://www.dell.com/community/Desktops-General-Read-Only/Dimension-4550-Power-Supply-Upgrade/td-p/3288662

Thanks for the link... that's a US site though... I need to find a UK supplier ideally but that looked like the right PS.

The problem I am having is that the plug that goes to the motherboard on my pc is a 20pin plug and it is a 24pin plug on the PS that I bought... (Ignore the text that says "PS that you sent" - this is a pic I've sent to the supplier trying to resolve the issue)

Plug on PS that I boughtPS that I need

20 pin PC are long long gone now.

just buy legacy PSU off ebay.

or  find any PC shop or store and call them and tell them you need 20 pin PSU.

use 20 years ago.. CNC , I do feel your pain there. (mill ? of some kind))

also many PSU have the 24/20 P1 connector as split (ATX) 

my advice to you with CNC with relic PC connected is keep spare PC on hand, for sure if down time is bad.

for sure spare PSU,for sure,

your ATX is the oldest of all,  with old PATA power plugs not SATA)

so those matter first. size FIT, then power same or more, 20 pin compliant and connector type and count.

5x  4pin molexs (PATA IDE legacy) 1x 20pin and 1 floppy power, my gawd  you use floppies>? and 1x 4pin CPU power plug.

im looking on ebay and is full or your PC there, if you look , there see those connectors?

ATX12v + 20 + PATA power.  finding split connectors, now is harder, 20/24spit.

new egg has over 700 PSU with split 20/204 connectors PSU

the problem is most have no PATA power  cables, just modern 2001 to now , SATA power

that makes buying new PSU hard now, 20 years old. even with 20/24 pin plug.

but if you do legacy search,

here one is. new.

https://www.newegg.com/p/1HU-009N-00069?Description=psu%20legacy&cm_re=psu_legacy-_-9SIA85V3GC9107-_-Product

Thanks for the reply.

Yeah you would not believe the antique PCs that are still running machines in factories. Mine is just a CNC router that I built myself running Mach3 control software. Apparently it is possible to get Mach3 running on the latest windows so perhaps it is time to upgrade and I will for sure get a spare PC sorted because this episode has made me face up to the fact that my whole operation is dependent on a 15yr old PC!

I used to work for an engineering firm that had a Wire EDM machine running from a 30yr old PC with Japanese MSDOS on it. Programs loaded from 3 1/2" floppy. Absolute nightmare when the floppy drive finally failed!

OK, so to put this thread to bed and in case anyone else ever has the same issue...

It turns out you can plug a 24pin motherboard power cable into a 20pin socket on the motherboard.

The last 4 pins are to provide extra power so in theory you could also plug a 20pin cable into a 24pin socket on a motherboard but this might not provide enough current draw to the motherboard so not advisable.

I am assuming that because I have only 20 pin socket on the motherboard it does not need the extra 4pins for more power.

Anyway, the pc is on and working.

Useful info...

http://www.playtool.com/pages/psucompat/compat.html