# Dell Dim 4550 case swap



## schw32m

Before we get started lets waylay all the Dell jokes, please. I have heard them all and I hold the opinion, at least as far as working on them, that the only good Dell is a dead Dell. Good for what they are they work adequately for what you get. 

I would never buy one.

Given all of that and due to several threads the last few days or so dealing with Dells, I decided to try a little experiment. Swapping the guts of a Dell into a standard ATX mid tower. 

The beastie below is a dimension 4550 configured as follows:

Intel (dells design) 865 socket 478 P-4 (2.53 Ghz Northwood core)
GeForce MX4
1 GB DDR ram
100Gb 5400 IDE HDD
DVD/R & CD/RW
FDD
Windows XP Pro
















These things are heavy and I really dislike the clam shell case. However I do see a lot of these of similar design as they are rugged and seem to hold up fairly well.


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## schw32m

*Disassembly*

First thing is to strip it down to the major component parts:






The parts that will be transferred. One of the fortunate things is the CPU heat sink mount. It is not an off size hole pattern and if the heat sink and shroud cannot be used in the configuration it was within the Dell, I can mount a standard 478 cooler with no problem. The holes line right up.






Its proposed home. An inexpensive mid tower that hasn't been in use since the shuttle AK31 that used to reside in it died.






Next: Modifications, assembly and preliminary testing


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## schw32m

The PSU and fan from the original case mounted in their new home. The case itself uses a dimpled style standoff system with a few adjuster holes for brass posts. Will accommodate ATX to Micro ATX.






Original idea was to place the MOBO directly in the case. However the I/O shield is integral to the original tray as shown. I didn't want to cut the tray and figured it would add some stiffness to the case so I decided to make the tray fit with minimal changes.






After marking the tray and slightly enlarging the holes so that it laid flush to the top of the dimples, I did a test fit to make sure the tray would position properly.






Back view after fitting. The fit was perfect and the I/O plate is flush against the back metal and clears the underside of the 90 mm fan.


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## schw32m

Final assembly of Mobo.

Motherboard fitted and mounted. Power cables removed for clarity.






At this point most are probably thinking "Yeah? So what? Simple mechanical assembly." Fear not oh padawan learner, this is where it takes a turn. The key to most Dells and the reason why they become such a pain to work with is the use of this little bugger. Normally located in the front faceplate and connected to the motherboard with a 34 pin ribbon cable.






The 0M686 front controller. It controls all power functions, USB, audio ports and just about anything else available on the front. It is connected to the switches and LEDs with a 16 pin ribbon cable. A variant of this board is found in just about every Dell made. Due to the size of the 34 pin (it is a mini cable) you can't by pass it even if you had the pin out of the MB. The saving grace is the ctrl_pnl (16 pin) connector at the top left of the board. Though normally connected with a ribbon to the switches, it is sized such that you can make individual connections from your switches here.

A quick search and the pin out for the 0M686 board was found. From there it was a simple hook up of the switches to get the machine to boot up properly. So I hooked it up to the test bench and off we went.

Initial boot screen






After POST






I had no drives or keyboard connected so of course it stalled after POST and the controller is just sitting on the bench unmounted as yet.

NEXT: A little fabrication to mount the controller board.


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## linkin

nice job  i love seeing a dell being put to good use.


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## schw32m

linkin said:


> nice job  i love seeing a dell being put to good use.



Thanks

Its been a fun little project. Though I have been posting the pictures over several days 90% of the actual work I did Sunday afternoon while listening to the Canada/US hockey game on the telly.


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## schw32m

The mounting of the front controller ended up being easier than I thought. I was figuring that I was going to have to fabricate a mounting bracket. But as it turned out the posts for the original USB board in there allowed me to have a prefab mount.

Front View






Rear View. There used to be a 2 port USB board there. But it had been moved to another project that didn't have a front port. 

Side note, before I started this I was actually considering stripping this case for remaining parts and drive cages and sending the remains to be recycled.






Cutting off the top two posts allowed a nice little place to put the controller. I couldn't mount it component side down as there would be clearance problems with the metal case lip. A couple dollops of silicone and the board was mounted.






Front access. I would have liked it if the audio jack had been on the other side so that I could have used the small hole for it, but taking the knock out from the other side didn't detract all that much from the look of the unit after mounting. Besides the door would be closed most of the time anyway.


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## schw32m

A couple of other things needed to be checked before final assembly. There was really no way to mount the big green heat sink shroud used in the Dell without a lot of major modifications to either this case or the shroud. In keeping with the idea that I wanted to do this all of this without having to make a lot of mods I needed to check on the ventilation to the heat sink. The side panel had a CPU vent port and I needed to check if it would line up with the Dell heat sink and would clear the top.






With the side panel on, the port lines up almost dead center with the heat sink and has about 1 mm clearance between the plastic tube and the top of the heat sink. I couldn't have asked for better. With the fins aligned the way they are the 90mm in the back will draw air pretty much the way it did with the original shroud.






While this may not have been terribly important, if the tube had not lined up I would have either changed the heat sink or put an 80mm fan in the side panel. Again, I wanted to avoid that option since the original design of the Dell ran almost dead silent and I didn't want to add additional fan noise if possible. Final testing will tell me if this set up works as I will keep a close eye on the temps.


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## linkin

You could dremel out a hole and some screw holes on the side panel, ditch the tube thing and use a 120mm fan. they are much quieter than 80mm.

could also use a 200mm fan, but they are a bit rarer, i think only coolermaster makes them. That would likely cool the entire mobo


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## schw32m

linkin said:


> You could dremel out a hole and some screw holes on the side panel, ditch the tube thing and use a 120mm fan. they are much quieter than 80mm.
> 
> could also use a 200mm fan, but they are a bit rarer, i think only coolermaster makes them. That would likely cool the entire mobo



Sure, I could do all that, but the thrust of this project was to do as much of a stock swap as possible with out major case, internal modifications or addition of parts. The MB itself only has one fan header. A flat 3 pin thing that looks like an audio connector from a cdrom. This was the reason why I wanted to keep the 90mm from the original Dell. One it fit the new case, and two it is thermally controlled by the MB and runs way slower than if connected to the molex without a separate fan controller.

If I had really wanted to do a bunch of modifications, I would have totally changed the fan configuration and power. What I would have done is to change the PSU to a 450 watt + that had a 120 fan, changed the CPU cooler and used an Agilent arctic cooler that I have laying around, mounted another 120 in front of the drive cage and tied it all in with a separate fan controller.

For a stock Dell configured P-4 Northwood, this would have been overkill. The most that I might have to do is to change the CPU cooler if the tube system doesn't keep the CPU temps within reasonable specs.

But your suggestions are duly noted.


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## schw32m

Front panel all wired up and ready to go. Functions are all tested and she lights up.  All that remains is to assemble the face plate and mount the drives.


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## schw32m

*Final Assembly*

Work and other stuff sometimes gets in the way so I didn't get to the final assembly until today.

Face plate on, preliminary drive mounting.






A little wire management.






IDE ribbons and other fun stuff installed.






Final configuration, running on the bench.






I did make a couple changes over the stock 4550. I changed the original cdrom/dvd to a beige Plexwriter combo to free up an IDE slot to put the removable drive cage in. Still have room for one more IDE if I so decide later.

In the end it is still a Dell, but it will make a fine little file/backup/archive/printer server. It will surf the 'net quite nicely and I might even consider putting free proxy on it to control the household internet network.

All in all it was a fun little project. 

Hope you enjoyed.


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## kuatous

*the 0M686*

was the a prerequisite for the on and off as well as the front mount LED because if not i am at a loss for what to case swap this bad boy.


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## schw32m

kuatous said:


> was the a prerequisite for the on and off as well as the front mount LED because if not i am at a loss for what to case swap this bad boy.



You could probably jumper it to make it constant on though I didn't see the sense in making the front panel inoperative.


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