How to perly install PSU in Dell Precision

[mknabster]

I need to upgrade the power supply in my Precision T3400 for the new GPU i'll be installing in it, so i just bought the Dell YN637 525W power supply. I have searched the manual, and i don't see anything in there about how to properly remove the old and install a new power supply. Can anyone give me some tips on how i can approach doing so? Thank you

[glc]

Doesn't look like Dell offers a service manual download. It shouldn't be too difficult, just open it up and look at it, you should be able to figure it out.

[mknabster]

I was reading into it a bit, and looking inside the tower, there are wires leading from the PSU underneath the CPU itself and out to the hard drives. I read one person so it's best to cut the wires off the PSU and take it out that way. They said the long way would be to take the CPU out completely then reapply all the thermal paste. I really would rather not cut them or remove the CPU honestly

[glc]

Can you post some pics? That sounds like a PITA.

What GPU are you installing, and what's the exact brand and model of the existing PSU?

[mknabster]

i'll take some pictures when i get home, but some quick specs on what i remember:

Current PSU is 375W Dell
Future PSU: Dell YN637 525W

GPU to be installed is the EVGA GTX 660, and i'll be leaving my current Quadro FX1700 in there too, along with everything else that's in there.

[glc]

Why do you want 2 dissimilar cards? What are you going to be USING this thing for?

[mknabster]

Well, buying a 2nd Quadro is too expensive for me, which is why i settled on the GTX. I won't be using them in SLI so that's not needed. I want the newer card for better rendering of animations and video, and the current Quadro will be for very basic stuff. I was planning on having the GTX power 2x 24in Ultrasharps, and the Quadro 1x vertical monitor. I guess i can take the quadro out since i really don't need it, but if the PSU can take both of them, why not keep it in there. I also wouldn't mind using the GTX for some gaming as well, couldn't hurt

[SARGE]

Originally Posted by mknabster I was reading into it a bit, and looking inside the tower, there are wires leading from the PSU underneath the CPU itself and out to the hard drives. I read one person so it's best to cut the wires off the PSU and take it out that way. They said the long way would be to take the CPU out completely then reapply all the thermal paste. I really would rather not cut them or remove the CPU honestly

I can't see why you would remove the CPU. They probably did it for cable management. I wouldn't cut wires on a working PSU - save it for a spare. If you unplug the drives, is there enough room under the board for the connectors to slide under? otherwise, I'd unplug just enough stuff to raise the board enough to pull wires out.

[mknabster]

I should be able to take some good pictures in a little bit, but from what i remember in the past, some of the wires do go underneath the motherboard in some places. But i would prefer not to cut the wires because i would like to keep it as a backup in case something happens.

[SARGE]

My case has an area below the board, like a channel, with rubber grommets on each side. The wires come out on other side then go to proper places. Remove the other side of your case and see if that's your type. Mine don't touch the board but encased in a hollow section of the board underneath.

[mknabster]

Maybe this will help, if not let me know so i can take some better pictures. From what i can see, it does look like the hard drive power cables go underneath the CPU housing, so the big black thing in the middle. Here we go:

[SARGE]

What in tarnation is that big black thing sitting on top of where the CPU is, in the last pic?

[tmathews]

It's hard to tell from the pictures but I'd think the black shell over the CPU is used to channel air through the heatsink. The six copper-colored nubs poking up through the top look like the ends of heat pipes. The heatsink should be pressed down against the CPU by more than just the plastic lid
so you should be able to remove the black shell without taking off the heatsink.

[mknabster]

Yea, that's what covers the CPU, so i'm guessing it helps channel the heat? No idea, but you should see under that thing, the heatsink on this is huge as you can imagine

[glc]

That's a plastic cooling duct, and it's removable without disturbing the heatsink. Dell uses a big passive heatsink with a duct to a case-mounted fan for cooling. In the top pic, top left, under the blue SATA data cable, see that tab? I think all you have to do is depress it (and possibly another one not visible in the pic) and it will slide or lift off.

Get us a clear closeup of the label on that existing PSU, please. Dell tends to underrate their PSU's, and that one may well have enough guts to run a 660 by itself - which is what I'd do anyway. Does that motherboard even have a second PCI-Ex16 slot? What exact CPU does this rig have?

[mknabster]

I believe the current PSU is the Dell K8956, but i'll take a picture of it later if you need it. It does have a 2nd slot, I actually moved the Quadro down to the 2nd one underneath the RAID card so the main one where i'll be putting the GTX in will cover the first 2 slots. And the CPU is a Core2Quad Q9550 2.83Ghz.

[glc]

A pic of the label so I can read the specs would be very helpful. I can't find any specific specs online for that unit.

[SARGE]

I would want to know how my entire rig is put together, down to every wire and how it gets there, even if I was keeping current PSU. Changing PSU on this rig and hidden wires, well that would be fun.

[mknabster]

Well, I do have the manual printed out which tells me literally everything in the computer ans where all the wires go form the PSU, so i do have something like that. Here's a picture for you glc:

[glc]

There's a decent chance that one has enough guts to run a 660, as long as it has a 6 pin PCI-E auxiliary power cable. It's showing a total of 30 amps on the +12v rails.

[mknabster]

Yea I believe it, but i feel safer getting the other one just in case, especially with all the other things that are running in there.

[glc]

Does the new one have a 6 pin?

[mknabster]

Yes, it has 2x 6 pins like the current one does.