I have questions Installing a New PSU to an old PC

[arcadeportal32]

Hi Tom's Hardware Community, I have a question..
Please read the whole question (do NOT say to replace the PC, I won't)

I still own the Very First PC I ever owned, I of course now own another more powerful PC, but I love keeping it for the nostalgic feel & it's more sentimental then anything (and playing MS-DOS games like DOOM natively). I would like to replace its VERY old and aging PSU currently inside it for a new one, but I don't know what PSU to choose?

This is the specs of the PC
ASUS A7N8X ATX Motherboard with optional & Working GamePort and COM2 port
AMD Athlon XP 2200+ 1800 MHz Thoroughbred Model A
2-1GB Sticks of DDR1 in Dual-Channel (2GB Total)
40GB IDE Main HDD (1TB External HDD for everything else & games)

Perriferals
nVidia GeForce 6200 GPU with 256MB DDR2 running in the PCI slot
SoundBlaster PCI128 Sound Card
IEEE-1394 FireWire Card
Old Modem Card <-- I don't obviously use this lol, but it is installed
Working 1.44MB Floppy Drive
3 DVD/CD-RW Burners, though I can obviously remove the first 2 if need be.

Now here is the CURRENT PSU's power specs

Future Power Model NO: WIN-400PS (Made in 2002)
ATX12V PSU
AC Input: 115/230V~,7.5A/4.5A,50-60Hz
DC OUTPUT: 400W for Pentium 4

[MAX 200W ->> +3.3V: 15A | +5V: 30.0A]
[+12V: 15.0A]
[-5V: 0.6A]
[-12V: 0.6A]
[+5VSB: 2.0A]

Can I USE a new PSU? Or do I have to buy one that is just as old?

 

[Dark Lord of Tech]

I think the PSU and motherboard are proprietary.

 

[arcadeportal32]

The PSU is proprietary but the Motherboard is a standard A7N8X board, which accepts a 20PIN ATX power cable Edit: The PSU is around the ATX12V 1.0 era, and the board is a Standard ATX format, and is not proprietary it's an off the shelf one basicly

 

[Martell1977]

You should be able to use a standard, new PSU, but you need to make sure it will have enough of the right connections and fits into the case properly. The motherboard connector will need to be a 20 pin or a 20+4 pin. You will need 4 molex connectors at least and one for the 3.5 drive, should you wish to sue it. I know many don't include the 3.5" drive connection, so this is one to watch for, but molex are still common.

Is this the same motherboard:
http://www.ebay.com/itm/Asus-A7N8X-motherboard-Nvidia-Nforce2-chipset-Socket-A-FSB-333-266MHz-3-DDR-40-/252684177596?hash=item3ad52690bc:g:bN8AAOSw241Yagfv

I'd say get a 400-450w PSU from Seasonic or EVGA(not B1, G1, W1 or P1 though)

 

[arcadeportal32]

Yes that is the same Motherboard Martell1977, it is dated on the BIOS 2002 - including in it's First Edition manual which I still have.

I'm pretty sure a new PSU will work, but im worried as the PC mostly uses 5V will it be an issue along the way?

It says according to most PSU calculators, my pc should have about 30amps on the 5v

 

[Martell1977]

Well, most of the PSU's I see are 20-24a on the 5v. But you have to remember that today's PSU's are much more efficient than back then so I'm not sure it would be an issue. PSU calculators are not very accurate, I haven't ever trusted them.