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Simple Power "Hack" Mac G4 (Sawtooth)

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Joined
Sep 19, 2015
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41
Motherboard
Ga-H97-D3H
CPU
i3-4170
Graphics
onboard intel 4400
Mac
  1. MacBook
Classic Mac
  1. 0
Mobile Phone
  1. 0
I just finished my first mod using an case of Power Mac G4 model Sawtooth.

Bought one from about U$40 here in Brazil. Shipped already free of motherboard, drives and power source. 8 bucks for shipping and that's all for the case. Good bargain in my opinion.

Here is a victim's picture before any work.

AAX00769-2.jpg


Well, I did a budget build (as cheap as possible), used only simple tools and tried to keep the case as original as possible.

I'm planning to show a little of this process in the next posts.


...and, of course, sorry for my poor english. :-/
 
First thing, I removed all the acrylic parts. Easy, just need two allen keys and screwdriver. Then removed everything else. The whitish plastic board first, then removed the back panel plate rivets using a drill. To remove the old motherboard's standoff I used a locking pliers. Then, HDD supports were removed, and the old cables too. There's a sticky and hard to remove tape fixing the old cables, the worst part of this tear down.

Finally removed the old wireless board support (drilled the rivets), speaker and front pannel. Brushed and cleaned everything.

AAX00757-3.jpg
 
As I said, I didn't have much money to built this hack. So I spent some time studying the possible hardware to buy (Following the Tonymac's Buyer's guide) keeping in mind the fact it must fit inside my g4 case with little effort (and fit in my budget :) ).

AAX00771-4.jpg


The complete list of parts:

Motherboard Gigabyte Ga-H97m-d3h (M from Mini ATX fits inside g4 case with little adjustments).
Intel I3 4170 (bought this by mistake. It would be better to buy an i3 4330, 40 50, 60 or 70). Anyway I managed to got it running fine.
Corsair Vengeance 8GB DDR3 1600
TP-link PCIe wireless card
IceBlade 12cm case fan (the g4 original fan uses a double connector, the new motherboards requiere a triple).
160GB WD 2.5 sata Harddrive (from my old macbook).

***Corsair CX430 Power Source ***
Hey, about the corsair CX430, it fits almost perfectly in the g4 case. Using one of these to hack a sawtooth saves work and any possible "disfiguration" of the acrylics back of this case. Even the PS on/off button lay down fine and acessible.

This computer was planed to be used to work with photography. Basically photoshop and lightroom work, so an external graphics card isn't necessary. In fact, it makes this build much easier. In the next posts I'll tell why.
 
In order to make my simple power mac mod I need to deal with three main adaptations in the old g4 case.

1. Fix the motherboard: removed the old standoffs and put new ones in correct places to receive the new mATX mobo.

2. Modify the case back panel to accommodate the mobo connectors, and connectors of the expansion slots.

3. Reuse the old front panel circuit.

Actually each one gave me a little challenge.

Let me talk about.

1. Fix the Motherboard
==============

I didn't find any kind of standoffs in the local shop of my city and i didn't want to wait for a shipping. So decided to use screws, nuts and washers (cardboard washers). The real challenging job here is to drill the case fixing holes in the exact places. After I did it, the mobo doesn't fit, fits one or two, the other not. Maybe if I had used thiner screws it would be easy. But there was no other option of screws, so I used these that fits veeeery tight on the mobo holes, drilled bigger holes in the case and made some larger washers cutting a thin metal sheet. Then, my standoffs could be moved a little, before I found the exact place to screw the nuts and fix it. Far from the ideal I know, but it did the job. (ahnn... and I used only 4 standoffs to fix the mobo. More holes, more difficult to place the mobo. ).

As I said, each standoff was fixed in the case using a nut. After fixed, I put 5 cardboard washers in each screw to raise the mobo. With the mobo placed, I fixed it using nuts.

The image below shows (out of focus :p ) in the bottom right one of these "homemade" standoffs.

AAX00795.jpg

The hardest part of fixing the mobo is to find the correct place (it deppends how you will work with the mobo connectors in the black pannel) and fix the tight standoffs. Maybe appears to be a easy job, but was a little challenging to me.
 
2. Modify the case back panel to accommodate the mobo connectors and expansion slots
=======================================================

By far the hardest part of any g4 mod. Same for me, but I did it as simple as possible.

Well, as I said, I didn't planned to use an external graphics card. The only expansion I planned to use was the PCIe wireless adapter.

I would to maintain the case as original as possible. So cut plastic acrylic or metal parts was not an option. I even hadn't a dremel to execute this job.

From other mod examples presented in this forum I learned the differences between the g4 original mobo and the new ones. For example, a new mATX like mine won't fit in the back panel without cutting metal and plastics. Actually, expansion slots and the sound connectors are much more closer in the mATX motherboards than the original g4 MB.


Then I decided to create a homemade back panel.

The mobo connectors should be privileged. The expansion PCIe connector closer to the sound connector would be not used (sacrificed), and the expansion slots would be no 4 but only 3. With this approach, I managed to maintain the case externally mostly unmodified.

So I took some pictures of back panel and motherboard connectors and drew a possible panel cutout scheme using adobe illustrator.

AAX00779-4.jpgAAX00780-3.jpgAAX00782-2.jpgAAX00783-2.jpg


Then I did a paper mockup to test. (I decided to make it in two parts, because it probably would be easier to make and to fit).

AAX00757-4.jpg
AAX00758-5.jpg

It appeared to be fine. Fitting almost exactly. Did some adaptations and then chose to use a sheet of metal to build it. I used one of those metal cans like cookie cans, easy to work and cut. In fact i did it using a common big scissors. Not the strongest material, but it appear to do the job.

AAX00763-5.jpg

After much cutting, metal curling, and two attempts, I had the pannels. \o/

12067357_892296970825361_944879771_n.jpg

and finally, I covered it with a black adhesive plastic film. But I think, the ideal would be paint it.

AAX00766-5.jpg
 
UPDATE: after I write this post, I realized that Minihac's post (link below) presents a simpler solution. Did not read it with attention when i was doing my mod. :thumbdown: Maybe you could try as him suggested, and use the common ground for everything.

3. Reuse the front panel circuit
===================

I didn't find any good or complete info about how to reuse the front panel. Anyway some info about the panel board's pinout here in tonymac help me a lot.

http://www.tonymacx86.com/powermac-g4/50357-pinout-circuit-g4-sawtooth-switch-cable.html

Fortunately, the sawtooth board appeared to be de simplest of all powermac g4 line. :)

Here is the pinout scheme, according minihack's post (take a look at his thread. there are pictures too):

------------------------------------------------------------
1.S3+ programming switch; Don't use.
2. No connection.
3.S2+ Reset switch.Use for reset switch + if you want
4. No connection.
5. S1 +; Use for Power Switch +
6. No connection.
7. Not useful (part of the apple circuit).
8. COMMON GROUND; Use for Power Switch -
9. Anode 1 (glows LED Green); Use for Power LED +
10. Anode 2 (glows yellow); Don't use.
------------------------------------------------------------

In my mod, I planned to use the original flat cable. Maintained the conector to panel board, and cut the cable near the other side.

I wished to connect 3 things: On/Off power switch, Power led and reset.

Started with the obrigatory power switch. So I used Pins 5 and 8. No modification needed in this case, just find the 5 and 8 pin out in the flat cable and did a soldering to a double connector. done!

So I started with the led. The panel has a two color led, and it uses pins 9 and 10 as Anodes and probably the common ground (8) as Catode (not sure). With the new mobo I need a new Catode, as the 8 was used for my power swtich. So I did a little soldering, and put the Catode (the middle led conector) connected in pin 7 (see first image below. the red wire). Then, my led connects to pins 7,9 and 10. I cut the connection between the led and another pin (see the second image). Not sure if it is really necessary, but appeared to be a good decision.

... and then put a triple connector in the flat cable end, connected the mobo and.. just the green worked... :(

AAX00770-5.jpg


In fact I think the led would glow orange when the computer is sleeping, but I was wrong. Just the green is working. Maybe someone could help me with that? suggestions?

Anyway the soldering to the pin 7 worked to the green glowing. :)

Finally, decided to use the reset original pinout

AAX00769-4.jpg


In the third modification I connected the Reset switch using pins 3 and 4. Did a soldering job (the yellow wire in the picture above). Put a double connector in the end of the flat cable, connected to the motherboard and... the reset switch didn't worked too. Damn! Maybe someone could help me with that too? Suggestions?

Well, my work in the front panel board ended with the on/off switch fine, and the green led working too. No orange sleep led ou reset switch yet. :/

AAX00775-5.jpg

Here, a picture of the soldering work in the flat cable motherboard's end (could be better):

AAX00772-5.jpg

And everything connected in the motherboard (could be better too):
AAX00789-2.jpg
 
Why did you replace the PCI brackets? The G4 ones work just fine as long as you line up the board properly.
 
because it makes necessary to cut the back plate and the plastic cover. the original brackets are perfect to receive the expansion cards, but the space between the connectors and expansion slots in the mobo is too short.

Maybe, it's a better solution to cut it carefully. It's the most common solution. But first I need to buy a Dremel.
 
because it makes necessary to cut the back plate and the plastic cover. the original brackets are perfect to receive the expansion cards, but the space between the connectors and expansion slots in the mobo is too short.

Maybe, it's a better solution to cut it carefully. It's the most common solution. But first I need to buy a Dremel.

Are you going to be able to keep the plastic somehow with this method?
 
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