Apple iMac G5
Summary
The iMac G5 is an all-in-one desktop computer made by Apple which had such an innovative and quirky new design platform that was used for many years; a computer behind a screen with stand. It was the first 64-bit iMac to come out (woah!! totally rad) and the first iMac to suffer from asphyxiation.
These were NOTORIOUS for running so hot that you could get rid of your dedicated room heater with confidence. The iMac G5 actually had 2 different designs for both 17-inch and 20-inch screen sizes, the latter of which came right near the end of the machine's run on the market which just so happened to make it much more reliable.
System Specifications
Processors:
IBM PowerPC 970FX "G5" single-core processors running at the following speeds for these models:
-2004 17": 1.6GHz or 1.8GHz
-2004 20": 1.8GHz
-Early 2005 17": 1.8GHz or 2GHz
-Early 2005 20": 2GHz
-Late 2005 17": 1.9GHz
-Late 2005 20": 2.1GHz
Front-side bus runs at 1/3 of the clock speed, so a 1.6GHz model has a 533MHz FSB, 1.8 is 600MHz, 1.9 is 633MHz, 2GHz is 667MHz (actually 666MHz if you don't round up), and 2.1GHz is 700MHz.
-17-inch: 1440x900 LCD panel
-20-inch: 1680x1050 LCD panel
-2004: nVidia GeForce FX 5200 Ultra with 64MB of DDR SDRAM
Note: "Education" models sold exclusively to those markets could be configured with a GeForce4 MX with 32MB of VRAM, however such a model doesn't seem to have any recent documentation proving its existence.
-Early 2005: ATI Radeon 9600 with 128MB of DDR SDRAM
-Late 2005: ATI Radeon X600 Pro with 128MB of DDR SDRAM (X600 XT for 20")
Note: Late 2005 models use a PCI Express protocol for the GPU, whereas older models use AGP 8X. This was due to a major redesign of the iMac G5 in Late 2005, which actually carried over to the Intel iMacs in January 2006.
-2004 and Early 2005: PC3200 DDR SDRAM, 2 DIMM slots supporting up to 2GB.
-Late 2005: PC2-4200 DDR2 SDRAM, 512MB soldered, one DIMM slot supporting a 2GB stick for 2.5GB of RAM total.
Note: Some people have reported success using a 4GB DDR2 DIMM, bringing the machine up to 4.5GB of RAM.
-All models: 3.5" Serial ATA/150 Hard Disk Drive
Note: Some sources have stated the education model from 2004 has a PATA hard drive; as far as I am aware, no one has really documented this model.
-Slimline IDE slot-loading Combo Drive or SuperDrive
-Texas Instruments TAS3004 Audio Chipset
-10/100 Ethernet (2004 models), Gigabit Ethernet (2005 models)
-56K V.92 Modem (not on Late 2005 models)
-3 USB 2.0 Ports
-2 FireWire 400/IEEE 1394 ports
-Headphone jack and Microphone jack
-RJ11 Modem Jack (not present on some models)
-RJ45 Ethernet Jack
-AirPort Extreme 802.11g WiFi, Bluetooth 1.1 (some models)
-Mini-VGA Video Output (can be used to extend with a software hack on OS X)
-Integrated iSight camera on the late 2005/"iSight" models
-2004 models: Mac OS X 10.3, upgradeable to 10.5.8, or 10.4.11 if your RAM is below 512MB
-all 2005 models: Mac OS X 10.4 (10.4.2 for iSight), upgradeable to 10.5.8, or 10.4.11 if you have an early 2005 model with less than 512MB of RAM.
-MorphOS (select models only)
-OpenBSD PowerPC
-Various PowerPC GNU+Linux distributions, such as Gentoo or Debian
Known Issues
While this iMac proved to be more popular than its predecessor, it was significantly less reliable. A lot of earlier units suffered from failing capacitors due to the capacitor plague that was affecting millions of computers being manufactured at the time. As such it is common practice to replace these when servicing an iMac G5, especially if it is an earlier model. iSight models do not have this issue, but there have been instances where these (and early intel iMacs) have had failed capacitors. All iMac G5 and early Intel iMac power supplies will suffer from failing capacitors, so replacing those is strongly encouraged.
Apple crammed a G5 processor into this system, which also caused lots of overheating and cooling issues with these iMacs. The iSight model seemed to have improved upon the cooling system, but it's not uncommon that you will hear about the earlier 2004 and 2005 models having issues with overheating and thermal throttling.
The LCD screens on these G5 iMacs, especially on the iSight models, can exhibit vertical lines popping up on the screen. This was actually a very widespread issue on LCD panels themselves manufactured during the mid 2000s, and is not related to GPU failure. Laptops like the HP Pavilion zd8000 and Dell Inspiron 9200 had this issue as well.
The iSight iMac G5s were once vulnerable to the iSeeYou exploit, to which an attacker would be able to modify the camera hardware itself through firmware to where it could disable the webcam status light. This means the camera could be on and you wouldn't have known anything about it. However, this exploit seems to have lost its relevancy and importance for almost a decade now.
My thoughts
If you're not experienced in repairing old computers this is not a machine for you. I've worked on both styles of this iMac, and in particular the iSight model (and the early Intel models), are the worst to service. You will see areas where Apple used shielding tape, and cheap plastic screw inserts. These are hell to work on, and it is very difficult to make the system look like it did before opening it. The earlier ones seem to be easier to work on, but they are also the worst in terms of reliability. The iMac G5 is a great example of a "pick your poison" situation; you either get to have easy access to components without risking major damage, but you also have worse reliability. The iSight models and the early Intels that use the same frame have somewhat better reliability, but they are a real pain in the ass to take apart without potentially damaging something. It's still not as bad as the slim unibody iMacs, though.
Unlike the iMac G4, the core design principles of this iMac still live on after 20 years. A compact all-in-one computer with an LCD screen, suspended with a sturdy "one-leg" stand. These were actually easier to work on without losing balance or stability compared to the iMac G4, and even the G3. It is very evident that the iMac G5's basic design principles actually function, while being aesthetically pleasing. You couldn't say that about some of Apple's designs from the Y2K era, especially if you're comparing this to the slot-loading iMac G3.
