Hello,

I am trying to figure out how to get this darn thing open!! It is a Mac G3 (everything's all in one - monitor, hard drive, motherboard, etc.) I figured out how to get the bottom open, which allows me to access the motherboard, but what I need is to get the top open, where the power supply is. The power supply needs to be replaced (the switch sparks when turned on).

So, when I am actually able to open it (how?), is it a specific "Apple" power supply? Will I need to find another Apple power supply to replace it? Or is there a way to simply bypass the switch and have it operated by an external switch?

Thanks for your help... I am very smart when it comes to PCs, but I know nothing when it comes to Macs... thanks!

Did anyone have a response to this? I'm having the same problem trying to open my G3 All in one. I can't get at the power supply...

You will need Phillips screwdriver #P2, jewelers flat-blade screwdriver 2-mm width, Torx T15 (known also as Mac Cracker), blunt thin pry tool such as table knife, and muffin tin to put screws in per order of removal.
1. Wait about half hour from shutdown of computer to allow high voltage in CRT circuits to dissipate. Unplug computer and practice anti-static grounding precautions.
2. Remove system tray by removing four screws on back of unit. This website has good explanation:
http://www.scienceman.com/pgs/trev_g3aio.html
Take system tray out completely.
3. Remove lower faceplate, which surrounds speakers and CD and floppy drive slots. Be patient with all Mac plastic case parts - they can be removed but process is slow. Pry tabs on bottom of faceplate down to clear tangs, and slowly work faceplate away from unit. When it won't go any farther than a few millimeters, get table knife and pry into screwdriver slots on sides of faceplate. Secret is to push knife into slots and only pry sideways a little amount. There is a tang inside slot that will be disengaged with sufficient work. When tangs are disengaged, faceplate will pull away from unit. Rotate faceplate around upper edge to disengage tabs along top, and remove faceplate.
4. Use Torx driver to remove four screws above and below speakers.
5. Use jewelers screwdriver to remove two 12-mm round plugs along top front edge of case. They are on the translucent part of the cover, about 10 cm from center on each side. When plugs are removed, use Torx driver to remove two screws which plugs covered.
6. Plastic cover can now be slid back off unit. If needed, gently pry with kitchen knife along front seam to get cover to move.
7. Use Phillips screwdriver to remove six screws which secure the perforated metal cover at the upper rear of unit. Two screws are on lower edges of cover on each side, one is on lower edge on back at center, and one is below power cord receptacle. With screws removed, cover will rotate up about front edge, disengaging tabs, and then cover can be removed.
8. The circuit boards containing the power supply and the CRT power and driver circuits can each be removed easily if the tang at lower aft corner of board is first disengaged. Board then slides up and out.

I discovered that my unit was sparking from CRT high-tension transformer, although I originally suspected the power supply.

I bet that's what mine is doing... Is there any way to fix it? You know, short of replacing major parts...

That's probably what my problem is too - thanks so much for the extremely detailed instructions. That will be my project this weekend.

I finally gave this a try... and let me tell you, unless you have the right tools and are properly trained, this is next to impossible just to get the cover off.

Another reason I don't buy Mac:

Replace power supply in PC - pop off cover, unscrew 4 screws, and replace

Replace power supply in Mac - waste 20 minutes trying to pry the stupid plastic off, bust a few pieces, finally remove, trace the mess of wires, replace, and have it go bad again in three months

I've made my decision.

I'm planning on simply transferring the motherboard to another case and wiring an external monitor into it... does anybody know the pin configuration for the VGA (or whatever it is) output on the motherboard... or can I put another video card into the pci slot and disable the built in monitor?

I have decided that the monitor is what is shorting out... not the power supply.

As I said before, I don't know much when it comes to Macs... so any help is appreciated... thanks!