PSU for Dell 8400 case

Well, I found a few replacement power supplies here, here and here and here is a standard ATX psu - all the same dimensions but let's check the specs for a decent psu like this Antec TP2-550EPS12V and yes they are all 5.9" (W) x 3.4" (H) x 5.5"(D).

Newegg currently has a good deal on that unit for $90 shipped

Or there is the Antec TRUEPOWERII TPII-550 for $80 shipped @ chiefvalue is my current favorite bang-per-buck PSU, can't go wrong w/ a 120mm PSU fan.

Which ones did you find on sale, and what do you mean by backwards if you dont' mind me asking... thanks

Ok I think I understand... Is yours like this?

You need a PSU w/o the switch, and the voltage selector / power plug to match the cutout in the chassis...

Yup thats the beast alright

Sure a hole saw and / or hacksaw (or jigsaw) will work well (use fine metal bits that cut smooth), just remove the PSU mobo & drives or remove PSU & drives only & seal up the mobo w/ some old clothes or plastic wrap (literally seal it up w/ masking or duct tape, isolating the mobo from the inside of the case so the metal shavings can't make contact w/ any parts) then cut away.
When finished, just use canned air to blow all the dust away then test-fit the PSU, if ok remove the wrap or reinstall everything.

Use any PSU you want, you are not "limited" to the 350w max that dell has to offer for replacement - that is the max you can get from them!
I would not get an Ultra, especially the X-connect. One of my coworkers had one die (the 500w) after only 2 months of use and was not stressing it or overloading it. seems to be common with that particular model of PSU so I don't trust them - too much of a crap shoot and you are most likely to get snake eyes.

Any one of these PSUs should do well:

SPARKLE ATX-350PN-B204 ATX 12V 2.0 350W $34 shipped @ ewiz
SPARKLE ATX-400PN-B204 ATX 12V 2.0 400W $41 shipped @ ewiz
COOLER MASTER Real Power RS-450-ACLY 450w $52 shipped @ buypc
FSP AX450-PN $57 shipped @ page
Antec TP-II 480W $72 shipped @ provantage
Antec TP-II 550W $80 shipped @ chiefvalue

In all honesty the SPI 400w (absolutely the best bang-per-buck currently on the market) should be more than good enough since it has plenty of +12v over the Dell's bestec old-school single rail design.

http://www.pcpowercooling.com/prod [...] r/dell.htm
http://www.pcpowercooling.com/prod [...] ?show=S47D


If you don't wont to mess around have a look at PC Power & Cooling, Dell section.

The problem with most modern Dell's isn't one of propriety, it's that the hole in the back is small, and shaped to fit only power supplies with the power plug in the same exact spot. 3/4 or more of the retail supplies on the market have the power plug mounted a little closer to the bottom. And a bunch of the ones that might work...have a power switch in the way.

That's the same problem facing many HP/Compaq owners.

Overkill, I don't believe in overkill, only just enough.
I think of a PSU like my car, I never drive full throttle all the time, only sometimes.


Too many PSU's share the amperage between the 3.3, 5 & 12volt rails, so all the power is not given if need on all the rails at once.

Nice. Looks like you're from the school of overkill also.
A bit of fun doing that job I bet.