OptiPlex 755 PSU form factor

Question

I have a Dell OptiPlex 755 SFF and there's a really annoying thing about the PSU : it interferes with the front 3.5inch bay and only allows slimline devices to fit. Now I want to replace it but there's a problem : I can't tell which form factor it is : is it TFX? Can I install a TFX PSU? or anything that isn't Dell?

redxps630 · Accepted Answer

Dimensions of stock psu is 6 cm x 21 cm x 8 cm.

you can use a standard TFX psu that has 24/4 pin and at least 275 w which is the power rating of stock psu

standard TFX Standard dimension for this form factor is: 85mm (W) x 65mm (H) x 175mm (D). TFX may be 5 mm wider/taller than stock psu in cross section. note the mounting holes spacing of 755 sff may not match standard TFX so you would need to use some other way to secure the psu inside case.

redxps630 · Answer

It is not standard TFX.

redxps630 · Answer

note how small space there is for psu in sff

Okmeque1 · Answer

But can you (if you can) specify the details of 6 cm x 21 cm x 8 cm in one of your replies with W, L and H. Thank you

redxps630 · Answer

high 80 mm wide 60 mm long 210 mm

redxps630 · Answer

I posted pic of psu but it does not show up.  here is link of pic https://imagedelivery.net/pjXEwQ5mgCM0WtJa4WheRQ/f2ab971e-4d8a-4965-1ae0-b969169c6500/ProductViewPop

Okmeque1 · Answer

@redxps630​ Yeah, does not look like standard TFX would fit as in the last reply, I saw the image and it's not only longer but slimmer (if you see what I mean) so might have to wait until someone makes a PSU that fits and doesn't protrude into the 3.5inch bay)

Okmeque1 · Answer

Solution for me rn is maybe to forgo the PSU entirely and make like a 12V only PSU and then try to cram in step-down voltage converters but it'll have to include the standby line so it's kind of cumbersome, might make it fit in one of the PCI slots backings...

bradthetechnut · Answer

That would totally be at your own risk.

Optiplex Desktops

OptiPlex 755 PSU form factor

Was this post helpful?