Janky OptiPlex 990 Gaming PC

Hello there and welcome to my Instructable. In this Instructable, I'll be showing you how I built what I think is a pretty cool, janky gaming PC with an old OptiPlex 990 and some 3D printed parts! It's not the best gaming PC, probably not the most reliable or safest gaming PC either, but definitely a fun weekend project to build and mess around with if that's what you're looking for.

Tools:

Screwdriver

Dremel with a cutoff wheel for metal

Drill with 3mm or 1/8" drill bit

Pliers

Hot glue gun

Blue tape and a Sharpie

Materials:

1x Dell OptiPlex 990 SFF - I can't easily link to one of these because you'll have to find someone selling it used locally or on eBay. Or, if you work in IT, you might be able to find one for free (like me!). You should make sure that the system is complete with all of the parts it needs to work, such as a storage drive, CPU, and RAM. Note that a 790 or 7010 SFF will work as well, it's just important we get a system that uses standard power supply connectors so anything newer than Intel 3rd gen will be a no-go.

1x PCIe Gen 3 x16 Riser Cable

1x Higher-Than-Stock Wattage PSU - The one you go with and how many watts it is depends on your GPU choice. I used a 450W unit.

1x GPU - Like with the PSU, you can kind of choose here and like with the main system, you'll probably have to find something used. However, your card really can't be taller than the PCIe bracket for it to fit in this design, so keep that in mind. I went with a blower-style GTX 980 that I got used.

9x M3x12 Socket Head Screw

2x M3x6 Socket Head Screw

6x M3x8 Socket Head Screw

17x M3 Hex Nut

This kit covers all of the above fasteners

2x PC Power Supply Screw

1x 3D Printed GPU Bracket - STL file is provided below. I recommend printing this part in PETG, or some other filament that has more temperature resistance than PLA like ABS, ASA, or Nylon. If you don't have a 3D printer but still want to do this project, feel free to check out my YouTube sponsor PCBWay and their 3D printing service.

1x 3D Printed PSU Bracket - STL file is provided below. I recommend printing this part in PETG, or some other filament that has more temperature resistance than PLA like ABS, ASA, or Nylon. If you don't have a 3D printer but still want to do this project, feel free to check out my YouTube sponsor PCBWay and their 3D printing service.

1x 3D Printed PSU Hole Cover - Same blurb of text as for the above two 3D printed parts applies!

1x 3D Printed PC Stand - Same blurb of text as for the above three 3D printed parts applies!

Note:

This build is specifically designed for this OptiPlex 790/990/7010 version of this idea, as that's the computer that I had on hand to build this system with. However, I completely understand that some of you will want to take the parts of this project and modify them for some different computers and purposes, so I've provided not only the STL files for easy 3D printing for the parts, but also the STEP files for easy modification of the parts in 3D software. Make sure you download the right type!

Like with all of my projects, I've got a YouTube video on this one as well! If you aren't coming here from the link in the description of that video, go ahead and give it a watch. It gives a great overview of what the project is, what it does, and what building it will entail, and is therefore really handy to have under your belt when you're building the project.

We're not going to be using this PSU for this build, and from this point forward it'll just end up getting in the way of our modifications - so go ahead and remove it! It should be three screws at the back, a small blue plastic cover at the front, and then down at the bottom of the case in the front there's a little lever with a blue sticker on it to press down on to release the unit. Once the unit is out, you can scrap it, sell it, or whatever.

Lay down a strip of blue tape along the bottom edge of the computer's side panel and mark out the cutout for the PCIe riser's cable. The cutout goes right up to the edge of the side panel, and the dimensions are marked in the image. After this is marked, feel free to take your Dremel and cut this piece of the panel out.

Here are the dimensions in written form as well, in case they help:

94x11mm rectangular cutout, one edge is the bottom edge of the side panel

Leftmost edge of rectangle is 66mm away from the rear edge of the side panel

Next, lay some more blue tape down in the bottom right corner of the side panel so that we can mark a 60x35mm rectangle to pass all of the PSU cables through into the computer. It doesn't really matter exactly where this rectangle cutout is positioned, but I'd recommend placing it in an area where it willl be covered up by the vertically mounted GPU once it's installed for a cleaner look. My cutout was 25mm away from the front edge of the side panel, and also 25mm away from the bottom of the side panel.

Next, after of course hitting the edges of both cutouts with some sandpaper to knock off general burrs and hopefully make the edges less sharp, I'd recommend using some strips of electrical tape to make the edges of the holes far less likely to cut into the cables that will be passed through them. The electrical tape is basically making a makeshift grommet here.

Now, again using more blue tape to mark on, we can mark all of the drill holes for the GPU and PSU mounts. I strongly recommend starting with the GPU mount, as it's more sensitive as to where it's placed on the side panel due to the fact that the PCIe riser cable can't end as freely as the power supply cables can. Marking the location for this part can be challenging, but if you mount the PCIe riser to the 3D print using two M3x12 screws and nuts as it will be in the finished product, you'll have a much better time.

Once the holes for the GPU mount are marked (reference the photos for more details), place the PSU mount on the panel as far above the GPU mount as you can get it. In my case, I basically just aligned the top edge of the PSU mount with the top of the side panel. I also recommend for this part aligning the back edge of it directly with the back edge of the side panel. Mark those holes, and you're technically ready to drill, but go on to the next step for a helpful detail you can add.

I strongly recommend drilling some holes in the side panel that you can route zip ties through in order to secure the power supply cables that will be traveling down to the cutout for them. I cut four holes which allowed me to secure two zip ties to the side panel, and their placement wasn't measured or precise, it was just rougly in-line with where the cable path would be. After adding these holes, you're good to go ahead and drill everything with a 3mm or 1/8" drill bit (though probably use something bigger for the zip tie holes) - and deburr stuff too!

Next up you can use the three screws that used to secure the original PSU to the chassis to mount the small 3D printed PSU hole cover plate where the stock PSU went. I designed this part so that the computer won't have a large gaping hole in the back of it from its missing stock PSU, both for cosmetic and airflow purposes.

Now you can use some M3x12 screws and matching nuts to mount the GPU mount to the side panel, with the nuts going in the slots for them in the 3D print, and the screws going through from the back of the side panel. Ensure that you don't mount the PCIe riser to this 3D print yet though - we'll do that in a moment once the side panel is on the case.

Then, mount the PSU mount to the side panel using the 6 M3x8 screws, however unlike with the GPU mount, these screws go through the 3D print from the top side and the nuts secure them on the back side of the side panel.

Now you can use two standard PC power supply screws to mount the PSU to the PSU mount, and then route all of its main cables down through the cable hole in the side panel. I don't recommend sinching the zip ties that you can put through the holes at this point, though, as it's better to do this once the cables are completely situated so that you can ensure they zip ties are doing their best job. Also, leave the PCIe power cable needed for the GPU out of the cable pass through hole for now, as that will plug into the GPU on the outside of the computer, not to a terminal inside.

Once the PSU is mounted to the panel, you can bring the panel over to the computer and plug in all of the power cables to the rest of the computer. I'd also recommend plugging in the PCIe riser cable to the motherboard at this point as well. Then, once all of the connections have been made, close the side panel while tucking all of the power cables into the spot where the stock power supply used to live, and make sure that the PCIe riser is making it out of its hole without getting pinched.

Yeah, now you have to unmount the PSU to mount the GPU, I know a bit annoying, but it's only two screws. Once the PSU is unmounted, it just has to be scooted off to the side of the chassis.

To mount the GPU, firstly mount the PCIe riser to the 3D printed GPU mount with two M3x12 screws and nuts like we did before when referencing where to put its holes. Then, slot the GPU into the PCIe slot like normal, and secure the PCIe bracket to the 3D print with two M3x6 screws and matching nuts.

Next up you can remount the power supply with its two screws, and then plug in the GPU's PCIe power cables. Then, you can use the zip ties to secure all of the cables, and you're done with the main part of the build! The last step will be gluing on a stand so that the computer isn't quite so tippy.

Now if you stand the construction you have up currently, you'll probably find that it's quite tippy. So, I made a stand with a nice, thin base that can be glued on to the middle of the bottom of the computer and because it's not super thick, the regular rubber feet already built into the case will work just fine to keep the system firmly planted, but the stand will help the computer not to get tipped over. I used some hot glue to attach this part.

I hope you enjoyed this project, and have fun working on your new janky PC. If you made this, share an "I Made It!" down below, because I'd love to see it - even if you heavily modified my 3D parts to fit them on a different system.