A good find for $45! I still think that the G4 iMacs are underated by many, and have a lot going for them - especially the later 1GHz and 1.25GHz USB2 models. I've torn-down and refurbished quite a number of these and so far have retained them all, much to the chagrin of my little lady.
The earlier models imho are slightly more difficult to work on, particularly to re-assemble the bottom housing to the main body. This is due to a 'floating' female connector within the main body, which must be carefully mated with the fixed connector within the bottom housing whilst reassembling top to bottom. I have seen cases where the 4 torx screws have been inserted and partially tightened before correct alignment with the aforementioned connector. The following helps to illustrate:
Early 700/800GHz model. Care required to correctly align connector (in centre of photo).
View attachment 879238
Later USB2 1GHz & 1.25GHz model.
View attachment 879239
iFixit doesn't appear to particularly recommend re-applying thermal paste, simply stating, "If you didn't remove or touch the heatsink you do not need to re-apply thermal paste."
I maintain that not only should the heat sinks be cleaned and new paste applied prior to refitment of the base unit, but during refurbishment the spring clip retaining heat sink over the processor should be removed, processor cleaned of old, hard paste, and new thermal paste applied. There's a good clip of this on YT which unfortunately I'm unable to immediately locate.
I
DON'T recommend using a can of compressed air with the straw-type nozzle inserted through the lower air inlet cooling holes of the base unit without dismantling. This would only serve to redistribute the mass of dust and debris, most of which which would resettle over the logic board.
Maxing these out with RAM memory, and also adding an SSD is relatively straight forward.
If eventually you plan to install an SSD, I've found that an ideal IDE to SATA converter (although not the cheapest) is the Manhattan 158282. This model even includes a J3 jumper in order to set IDE Master, Slave or Cable Select mode. I've also used a generic converter costing just a few dollars, although you get what you pay for, i.e. no mode setting jumper, the soldering of components is of very poor quality with uncleaned resin deposits. I took a gamble on one, but spent over an hour meticulously cleaning off all the dried resin deposits. It worked, but whether it would have 'out of the box' is debatable. I've used both Kingston and 240 Gb Sandisk SSD's which functioned just fine.
Another tip if installing an SSD. Attach the SSD to the top of the optical drive using double-sided tape, or velcro tapes. I cringe when I watch a video like
THIS (31:29 - 33:30) where an SSD is installed, pushed inside and 'hoped for the best!' It takes just a few mins longer to securely attach, and is a far more professional approach. You'll also note on the same video (at 38:28 onward) that he re-assembles the bottom housing to the main body without cleaning/re-applying thermal paste. Not recommended!
Like Weckart, I too remove the fan unit to ensure total cleaning. I've also disassembled the fan on both my 17" and 20" 1.25GHz iMacs in order to relube the spindle, but with hindsight this was probably overkill.
If anyone should find a G4 iMac with a bluetooth module installed, imho it's quite a rarity. I've retrofitted one on a 20" which necessitates removal of the logic board, not so difficult - but what is particularly challenging is finding the correct bluetooth card and cable.
HERE's a link to the bluetooth card & cable. Happy hunting!
