Introduction: Case Mod for Non-Standard Motherboard

Do you have an old motherboard and a case, but the case could use more stand-offs to properly mount the board? This Instructable may be for you.

In this example, a dual PII Xeon motherboard and processors are installed in a Gateway G6 - 333 case (LPMINI tower). With the unmodified case, we need three more stand-off mounts to install the processor support brackets. Without the brackets solidly mounted, the weight of the processors can flex the motherboard. These PII Xeons are about 3 pounds each.

My disclaimer: Do not attempt this unless you feel comfortable fiddling with computer internals and drilling holes in metal. If anything goes wrong, it is not my fault.

This is my first Instructable. Constructive criticism is welcome _

Step 1: Parts

Here are the particulars I used for this tutorial.

Gateway G6 - 333 Case
Soyo D6IGA Motherboard
PII Xeon mounting brackets
2x Intel PII Xeon processors

Step 2: Tools and Materials


Safety Glasses - most important

1. Sharpie or some other marking tool
2. Ruler
3. Screwdriver
4. Pliers
5. Screws with matching nuts
- These screws should be able to fit through the motherboard holes. One screw for each stand-off to be made.
6. Small Round File
7. Drill
8. Bit (as close to the diameter of the screws as possible)


9. Small Flat File
10. Bolt Cutter
11. Improvised stand-offs
- These can be substituted with extra nuts of a larger inner diameter than the screws.
- Those in the third picture are parts from a PIII mounting bracket.

Step 3: Marking and Drilling Holes

Remove the side panel covers from the computer case. Remove any detachable drive mounts, etc. that might get in the way while you work on the inside of the case.


We need to identify which motherboard holes don't line up with stand-off mounts, then mark those corresponding spots on the case. Take the motherboard by the edges and set it in place.* Use the Sharpie and ruler to mark the spots where mounts need to be added.

Also, check for extra mounts that would sit under the motherboard, away from the board's holes. Use the Sharpie to mark these.
1. If these sit under exposed leads on the bottom of the board, you will need to remove them. Some newer cases have screw-type stand-offs. The stand-offs in this particular old case are the permanent-type and can be removed with pliers. Grip the stand-off and bend side to side until the stand-off comes out.
2. Those stand-offs that sit under smooth, unexposed parts of the motherboard can be covered with electrical tape.


Put on safety glasses, first. I made a test hole (behind where the power supply would be) to get a feel for things before continuing. The holes can now be drilled. Keep the drill perpendicular to the panel and centered for each hole.

* Just to be safe, you can use an ESD wrist-strap while handling the motherboard.

Step 4: Mounting Holes

This can be the most time consuming step, if you do not have a wide enough bit for drilling the mounting holes.

Check whether the screws fit the holes. If the holes are too small, use the round file to expand them. Try to file the edge of the holes evenly all the way around. Once the screws can freely sit in the holes, things are good to go.

Step 5: New Stand-offs

In the first image, I have set the improvised stand-offs on the panel. The matching screws are hanging through the corresponding motherboard holes.

Depending on how much of an angle you have to use to set the board in the case, this step can be difficult.

Put the screws through whatever brackets, then through the motherboard (second image). Partially screw the stand-offs onto the ends of the screws, so the screws still have room to move side to side still. Leave enough of the end of the screw to pass through the holes in the case. Then, put the back of the board into the back of the case. From there, carefully lower the front of the board while making sure the screw ends pass through the case holes (third image). I used the round file to guide the ends into the holes. If the stand-offs are threaded to the screws, screw them in the rest of the way.

I have not used nuts as stand-offs for this, but it is probably fairly difficult to get right. Once the screws pass through both the nuts and the case holes, everything should follow the same.

Before continuing, screw in and secure the rest of the board where the pre-existing stand-offs are.

Step 6: Securing the Stand-offs

For each stand-off, start screwing a nut onto the end of the screw. For threaded stand-offs, hold the screw in place with the screwdriver and tighten the nut with the pliers. For loose stand-offs (with nuts), hold the outer nut in place with pliers while turning the screw from the other side.

Cutting Screws Down to Size:

After adding all the nuts, I completed the following optional step. The screws that I used were quite long, but they were the only suitable ones I had to use. They were long enough that I could not put the outer panel back onto this side of the case.

*** This is where the bolt cutters and flat file come in. ***

Put on safety glasses before continuing. Depending on how hard the screw's metal is, the end may shoot off across the room when you cut it. Get the jaws of the cutter over the screw ends as close as possible to the case. Cut off the ends, then file off the sharp and warped parts of the remaining ends. This will make it easier to take the screws out at a later time, if needed.

Step 7: Finished

With the brackets secured, it is time to slide the processors in. Six pounds of old school processors fit well and feel solidly secured.

I hope this Instructable is useful in some way.

Thank you.