This Imac G5 logic board is now running attached to my desk and is what I use to update this blog, I will leave this topic for another day.
Anyway. I looked around for a good place to buy some cheap parts. I am putting this together as a MythTV box so I brought that into consideration when choosing the parts. After searching around, I found this low price computer store http://msy.com.au.
After looking through their price list, I ended up with the following:
I was choosing between a Gigabyte 945GCM-S2L and an Asus P5GC-MX/1333. They are mostly identical (layout, chipset, etc.) Well, the Asus costs $2 more, but the Gigabyte has 10/100/1000 onboard ethernet, whereas the Asus only had a 10/100. So I ended up with the Gigabyte. $59.
At that time the quad core processors still costs a fair bit (plus MythTV isn't going to need that much CPU power.) Based on the MythTV forums, even the lowest end E2140 is more than enough for what I want to do. Balancing the costs (and the thought that I might use this as a desktop computer later on) I ended up with a E2200. $107
1G DDR2 Kingston. $32
Seeing that the main reason I want to upgrade my old MythTV box, is so that I can record/watch High Definition (HD) content. The old box can actually do that, but the onboard SIS video chipset only displays a weird green screen whenever I try to display HD content.... plus it didn't have an AGP slot.. only 2 PCI slots which was already taken up by the 2 tuners I have. So I thought a really big drive would be helpful... I could record months of shows before I need to erase some. So after considering everything, I chose a 750 Gigabyte seagate hard drive. $247.00
That's all the parts that (I thought) I needed. Next was to test fit the motherboard:
Looks like a good fit. Once I could modify the back panel the PCI slots should line up properly with the apple back panel covers just right.
Next problem is the G4's power supply is not standard ATX. To make matters worse, it looks like it's broken. At that time I couldn't be bothered to attempt to repair it (I may someday) so I just decided to put the innards of an ATX power supply in the G4's power supply case. This preserves the look at the back and the power cord still goes into the same place.
Shown here on the left is the original Apple power supply, on the right is the cheapo ATX power supply. Size is almost the same. No modification was needed to transfer the ATX innards except drilling a few screw holes.
Here is the ATX parts screwed on the Apple power supply case. You can see some of the screw holes have to be enlarged, and one (upper left) has to be drilled.
I then somehow managed to modify the case so that the motherboard fit. I had to cut a hole in the back panel because the G4 wasn't ATX standard. I had to remove some of the original screw standoffs because they dont match the motherboard's and they would short something out if I leave them in place. I then replaced them with metal PCB standoffs. I remember after having done all that the case refused to close and I had to desolder some of the capacitors and mount them lying down to keep them from hitting some part of the case. In the excitement I also somehow forgot to take any pictures of this and all I have is the finished product:
I will someday have to take this all apart for cleaning, and I will take some pictures and update this entry.