Did Dell Screw Up?

[billdcat4]

I bought my Dell Dimension XPS Gen 3 in August of 2004. This past January, I had some troubles with my PC. At the conclusion of my 12-page thread my PC was dead, as well as my logitech wireless keyboard and mouse.

A couple of weeks ago I put a WD Caviar hard drive in my PC, and miraculously it came back to life. In the months in between, I took my PC apart. The CPU was out of the box for maybe 3 of those months.

In examining my HSF setup I noticed something strange. Before I tell about that, I have to write up what CPU cooling system I have. The Heatsink sits on top of the CPU with a plastic shroud on top of that. In the orientation of the case standing upright, it has two 120mm fans to the left of the Heatsink:

The top fan blows air from the HSF out of the PC. The bottom fan sucks air onto the heatsink. Now, I don't know if that makes thermal sense at all? Wouldn't the two fans just fight each other?

The strange thing that I found was a black piece of plastic in the duct by the top fan. It completely blocked off the fan from the rest of the HSF. Obviously, this seems very wrong. I took out the piece of plastic, it was stuck in there by its sticky edges.

Does this setup make any sense? Should I change the orientation of the fans?

 

[dasickninja]

Is that one of the BTX based XPS's or does it use ATX? I can't really tell by the picture, but I'm guessing ATX. If the two fans in the rear are set to exhaust heat, then there really shouldn't be any thermal issues. I guess. :?

 

[billdcat4]

Is that one of the BTX based XPS's or does it use ATX? I can't really tell by the picture, but I'm guessing ATX. If the two fans in the rear are set to exhaust heat, then there really shouldn't be any thermal issues. I guess. :?

Its not BTX, but not ATX either. Its quite proprietary. It has 6 expansion slots as opposed to ATX's 7 and mATX's 4. The PSU is in a separate section, taking up the whole bottom of the case.

Does it make sense, or should I reverse one of the fans?

 

[dasickninja]

Umm, what are the temps and what is the processor?

 

[billdcat4]

Maybe not the best configuration but i'm sure Dell had a good reason for the configuration.

yea, but did Dell mean for that piece of plastic to be there? It was there for 2.5yrs. It completely isolated the top fan.

Umm, what are the temps and what is the processor?

the CPU is a Pentium 4 540 Prescott w/ Heatburst.

Ill check temps now. What should I use, Speedfan?

 

[dasickninja]

That and Intel's TAT (you can download it here) as well as CoreTemp so we can get the best readings.

 

[billdcat4]

That and Intel's TAT (you can download it here) as well as CoreTemp so we can get the best readings.

I can only get load temps now. Im streaming a movie in Firefox, and for some reason its taking up ~30-50% of my CPU cycles. Ill encode video and get it up to 100%.

Give me a couple min

*EDIT* Coretemp wont run since its not a Core CPU

Speedfan only gives me the temps for my Hard Drive

TAT says I have an invalid processor


What now?

 

[dasickninja]

I'm at a loss...

 

[billdcat4]

I'm at a loss...

But what about that piece of plastic covering the top fan?

 

[dasickninja]

I say leave it all alone. Its probably there to direct airflow.

 

[billdcat4]

I say leave it all alone. Its probably there to direct airflow.

Dude, it was completely blocking the airflow of the top fan. I took it out weeks ago.

It was just a piece of plastic with sticky edges stuck in the green duct

 

[puff]

I read somewhere that that piece of plastic is to cool the Capacitors below the processor, however i removed that piece of plastic long ago. Even later I modded a zalman 9500 onto the xps because the stock cooling was crap. Ill post pics

 

[dasickninja]

*Shrugs*

Its a Dell. What can I say.

 

[billdcat4]

*Shrugs*

Its a Dell. What can I say.

The overall quality isnt that bad. Look at that wiring!

I ripped it all out and put it back, so you cant really tell, but all of the psu cables were tied up and clipped to the mobo plate. Great stuff

 

[r0x0r]

Take mpilch's advice and just leave it alone; it's probably a vacuum or something like that.

Whatever it is, there's a reason for it. Your PC ran fine for nearly 2 1/2 years and it wasn't your CPU that caused it to die, it was your hard drive.

If it worked before and you haven't done anything drastic, it will work now. Dell's engineers are paid to make sure that people don't send their computers back with CPU's that melted at stock speeds.

 

[crazywheels]

it's a dell, i would probably would have left it alone. That piece is there for a reason.

 

[billdcat4]

Take mpilch's advice and just leave it alone; it's probably a vacuum or something like that.

Whatever it is, there's a reason for it. Your PC ran fine for nearly 2 1/2 years and it wasn't your CPU that caused it to die, it was your hard drive.

If it worked before and you haven't done anything drastic, it will work now. Dell's engineers are paid to make sure that people don't send their computers back with CPU's that melted at stock speeds.

but it rendered the purpose of the top fan moot. It made it as if the fan wasnt even there. Theres no mystery or Dell magic here, someone at the factory just f*cked up and left it in. Why put a fan in there if all it does is suck at a piece of plastic, and if the peice was meant to be there, why not have it be part of the general green mold?

 

[lmimmfn]

smoke a cigarette with the plastic on and off and see where the smoke goes, for fun drop the cig on the mobo and see if it will light, best thing for those dells :twisted:

 

[fyter]

It's really hard to tell what you are saying without being able to see this "sticky black plastic" you are talking about. From the pictures, it's obvious that it was designed to pass air through the CPU heatsink, and it would in that configuration, as long as you leave the square piece on the end, but without knowing exactly how the extra piece was oriented, it's impossible to tell.

 

[r0x0r]

Take mpilch's advice and just leave it alone; it's probably a vacuum or something like that.

Whatever it is, there's a reason for it. Your PC ran fine for nearly 2 1/2 years and it wasn't your CPU that caused it to die, it was your hard drive.

If it worked before and you haven't done anything drastic, it will work now. Dell's engineers are paid to make sure that people don't send their computers back with CPU's that melted at stock speeds.

but it rendered the purpose of the top fan moot. It made it as if the fan wasnt even there. Theres no mystery or Dell magic here, someone at the factory just f*cked up and left it in. Why put a fan in there if all it does is suck at a piece of plastic, and if the peice was meant to be there, why not have it be part of the general green mold?

Ask Dell that. Your CPU ran fine for 2 1/2 years (and is still running) so ther's a reason for it. I don't believe anyone screwed up because as you wrote about the cooling setup,

Its quite proprietary

I'm also failing to see the logic in it but it didn't seem detrimental.

On another note the Xbox 360 uses a similar cooling arrangement as well.

 

[billdcat4]

It's really hard to tell what you are saying without being able to see this "sticky black plastic" you are talking about. From the pictures, it's obvious that it was designed to pass air through the CPU heatsink, and it would in that configuration, as long as you leave the square piece on the end, but without knowing exactly how the extra piece was oriented, it's impossible to tell.

It wasnt on the other side of the HSF, it was less then an inch from the top fan, blocking off all airflow from that fan.

Here is where the piece was.

Sorry for the sloppy editing.... the red outline is where the plastic piece was.

*EDIT* after some searching, I foudn the piece of plastic. Ill go stel my little brothers canon now and take a pic.

 

[fyter]

So, the white part was open? It looks to me like air direction/turbulance control. They probably found that adding the plastic caused the air to flow across the heatsink rather than directly at it in that configuration. The smoke idea is a good one to use to see what I'm talking about. It is possible, though, that the configuration used was intended more specifically for a CPU without a heat-sink fan.

 

[billdcat4]

So, the white part was open? It looks to me like air direction/turbulance control. They probably found that adding the plastic caused the air to flow across the heatsink rather than directly at it in that configuration. The smoke idea is a good one to use to see what I'm talking about. It is possible, though, that the configuration used was intended more specifically for a CPU without a heat-sink fan.

the white part was NOT open. That whole area was closed. The top fan was COMPLETELY isolated from the rest of the PC. It was just sucking at a piece of plastic for 2.5yrs. No air went thru there, until now.

Here is the infamous peice of black plastic (flash makes it look grey)

tow of the three edges are sticky, but not the one on the right (in both pics.) Then again, the piece was held securely in by the other flaps. There was SOO much dust between the plastic piece and the fan. I dont mean dust bunnies, I mean dust ELEPHANTS.

 

[r0x0r]

There doesn't seem to be any small inlets for the intake fan to disperse the air, so I'd assume that now that you've gotten rid of that black plastic it would be safe to flip the intake fan around so it becomes an exhaust fan so you can double your cooling.

 

[fyter]

If that's the case, then:
A. Someone forgot to take it off when installing it, or
B. In the midst of a redesign, someone decided it was cheaper to stick plastic in front of the fan, rather then take it off.

If you reverse the fan to make it dual exhaust, leave the gray square piece off, else you'll end up with a vacuum (or is that a piece of mesh screen?). Personally, I find that using external air to cool a cpu works better than two exhaust fans working off of warm case air, but it would solve problems with other devices overheating (like, perhaps, harddrives).