Contribute
Register

G4 MDD conversion to mATX

Status
Not open for further replies.
Joined
May 27, 2010
Messages
2,364
Motherboard
Dell Optiplex 9030 All in One
CPU
i5-4690K
Graphics
HD 4600
Mac
  1. Mac mini
Classic Mac
  1. iMac
Mobile Phone
  1. iOS
You may remember me posting a long time ago (well a few months back anyway) about my full ATX conversion to an MDD case (link at the bottom of my sig.). However I know also that the case is more likely wanted to be used for an mATX where the board is mounted in the original door position. So, after a while I re-visited this!

First, the problem:

mddrear.jpg

The mirror drive door model, unlike all the other G4s has a reversed PCI slot configuration. This makes it impossible to re-use or re-purpose the original door mounting - especially as Apple seem to have gone to a lot of trouble to mount everything on the door in a way that makes it as difficult as possible! I have at various times tried to cut away some parts and keep others in an attempt to keep the "square" look of the back, but without welding gear and a lot of metal skills this is not possible.

So I turned to looking at what could be achieved by the hacker friendly methods of drilling and dremeling and trying to avoid using glue!

Earlier G4s all had a single skin (one metal plate) construction and used a plastic hinge latch to get them to close. The MDD uses a double skin with the outer skin having metal clips that form a strong closing latch that is much nicer than the horrible piece of plastic.

p7250890.jpg

The inner skin of the MDD door however carries the motherboard and has a shape that is generally the same as the single skin present on the earlier G4s, so having removed the door from a G4 Sawtooth model, cutting a few holes in it to match it to some holes in the original MDD inner, trimming some edge parts and holding it up to the MDD body we see this:

p7250889.jpg

The slipper fits! Or in other words a bit of hacking with a Dremel and we get a new 2 skin door made up from the outer skin of an MDD and the door from a Sawtooth (or other unloved early G4).

Other things needed to make it fit (complete with the hinge from the early G4) are: trim the hinge ends and drill new holes in the MDD floor to match the new hinge, and reduce slightly the height of the I/O panel from the Sawtooth. This last bit sounds daunting, but in reality it is this:

p7260911.jpg

In the picture above, the area around the PCI slots has been reduced by making saw cuts in line with where the original two rivet holes are in the panel top, removing the original lip and folding over the remaining metal to make a new (lower) closing edge.

This allows you to get to a point where you have a door which has the closing mechanism of the G4, and an mATX (ish) profile and hinge mechanism from an early G4 which will shut properly. However, in this state alone of course you then have achieved a back panel that on one side is effectively a straight line and on the other is shaped like an old G4. However, a simple cosmetic way to hide this fact is by using a pair of matched panels which does not make the difference in shapes quite so obvious:

p7260898.jpg

Note that in the picture above, I have actually used an mATX I/O plate from a Lian Li case - bonding this extra metal work from the Lian Li to the framework provided by the G4 Sawtooth door provides a combination that is now fully mATX compliant and gives adequate extra reinforcement to the rear panel.

The two parts of the door are held together by countersunk M3 6mm screws into nyloc nuts and standoffs are M3 threaded and approximately 6mm. The Lian Li I/O plate is bonded by JB weld to the inner door alone.

The original switch has been hacked to re-use it and the power led and the signals pass to the motherboard via the original ribbon cable. Also a HDD activity light has been placed behind where the headphone socket was so as to glow red whenever the hard disk is accessed.

A small laser cut panel at the front which has threaded holes matching positions of rivets in the MDD case provides a mount point for a new I/O panel - here is the front:

p7260894.jpg


p7260895.jpg

and the rear of this panel:

p7260906.jpg

The original PSU case was re-used to house a 500W power supply from a Shuttle PC.

p7260902on.jpg


p7260903.jpg

Cables are routed via the plastic panel to keep wiring clutter to a minimum and a 140mm fan at the front sucks air in to keep things cool:

p7260891.jpg

The original drive holder is re-used, but I have cut it down slightly to avoid any problems with large graphics card.

p7260901.jpg

The result is a drive holder that will take a single 3.5" HDD and a 2.5" SSD (via a conversion bracket). There is ample space inside the case however to mount a few more drives if required.

In the final version (update soon) I'll put in a cable tidy to hide the cabling at the bottom of the case.

While of course I have cut the cosmetic panels with a laser cutter, please remember that all lasers do is cut very precise holes in flat materials like acrylic. With patience the same results can be achieved in a workshop with a saw, a drill and some acrylic sheet (or wood/mdf!!). The key to the success of this mod though I think is in using the MDD parts together with the door from earlier G4s - which can often be picked up on eBay for a tenner.


I'll be putting some more specific detail on this stuff on my home page where I'll also be posting a video - however as I have a very slow internet connection that video won't have finished uploading for a good few hours yet.


Thanks for reading and hope you like my different take on the MDD.
 
Looks good Minihack.

Those MDD G4 cases were very cool, it's good to see that you were able to repurpose this one and have it turn out so well.
 
Love the "A Laser Hive Conversion" Nice little touch.

As always mini amazing work from you!
 
Thanks for the positive comments.

For anyone doing this type of conversion, it is worthwhile mentioning that the power supply conversion is pretty much the same as doing one to put a power supply into the G5 housing. At one end there is space for 2 x 60mm fans, there is then a cable outlet half way down the case.

I chose to use the cable outlet for just the hard drive power and at the inlet end I put one 60mm fan but used the space for the second to output all my other cables. The shuttle supply as original has just one outlet fan - so I kept the outlet fan plus the single 60mm inlet. Dimensions of the power supply case are: 60mm x 290mm x 125mm. Probably the cheapest way then to convert that case is to use a normal ATX supply with a top fan and then remove the top fan the same way you would for the G5 to get it all in.

Temperatures inside the case are similar at the moment to the ones I have been getting running the same processor and board inside my Quicksilver case - i.e around 30C at idle. There is though in the MDD room for a taller aftermarket CPU cooler because using the original PSU case gives about another 4cm clearance over the space available in the other G4 models (which are normally limited to coolers not much above the stock Intel cooler height).
 
Nice Mod!! I am about to embark on my own MDD conversion to mATX but I'm sure my back panel wont look as sweet though. Well Done!
 
Hi Minimac,

that looks really great. At present I have a similar project, converting a MDD case, but I will attach the board not to the hatch side but to wall. That should allow to install a DVD drive. And makes wiring a little bit easyer.

Do you recall the wiring of the front panel? I'd like to connect at least the switch and the LED, if possible the front audio also. In my case, the front panel is still in place and I'm tired of drilling rivets out.

Thanks, cheers and greetings

Martin
 
Hi Martin,
The wiring of the front panel switch by me was basically a great big kludge (!). I made some notes on what I tried to find with a multimeter at the connector pins and these are those notes:

Pin 5, 7 and 9 earths. (can be used as power switch common).

2 is sw +

1 is pw LED +

Pin numbering is basically if you have the original connector and ribbon wires, the "RED" coloured wire (all others are black) is "1" and the others number off from it.

I remember that the internal micro chip (probably does sleep circuitry pulsing for the Mac?) needs to be pulled off and there may also be some traces to cut.

Front audio connectors for the old Macs never work as they don't conform to HD Audio standard so I threw it away (or more accurately drilled right down the middle of the headphone socket and put my red HD activity light in there). Some of the wires on the ribbon connector can be seen to be not connected and I routed my HD+ and HD - signals via them so that I was able just to use the original connector. I think I used wires 8 and 10 for that.....

The board looks a real mess inside the metal can after me attacking it majorly to lever off chips and bridge solder tracks, but if I get a chance I will pull it from my hack and take a picture. Problem though is that I love this hack and it works really well, so for the moment I am running my laser business from it in my office.
 
Oh yes, one other thing. In case you didn't realise the little metal can that contains the switch pcb looks like it is riveted on, but the two black little mushroom looking things are actually re-useable fixings so definitely don't drill them out. Instead put a thin knife under the edge of them and just lift up the "head" you'll see it is actually attached to a plastic leg which when you pull that out releases the metal can so you can take it off.
 
Thanks again, that helps a lot. Meanwhile I said goodbye to the idea of using front audio. If there's time, I'll start wiring this afternoon. Hope, my missing parts arrive today.

I'll show pictures when everything's working.

Cheers

Martin
 
Status
Not open for further replies.
Back
Top