upgrading power supply???

i have an old G4 MDD dual 1.0 GHz that went dead on me about a year and a half ago. i had just had a baby then, so i let it gather dust then went about trying to fix it about a year later. i did a logic board, CPU, pulled all of everything, put all of everything back, and did it all again and again.

i was finally given a power supply from a friend and lo and behold, it worked. it ran fine for a while, even took an upgrade to 10.5. then one day i came home and noticed the power had gone out. i leave my computer in sleep mode, and feared the worst, and sure enough, the computer was dead again. all i get is a briefly lit front power button LED when i hold down the button. no noises, no signs of life whatsoever. EXACTLY like last time.

so i know it's a power supply. i suspect the two optical drives, two hard drives, and max RAM may be drawing too much power and bumming out the power supply. does anyone know if there is a power supply that can handle more juice and can fit in this computer? i'd like to fix it once and for all instead of throwing PS's at this thing (which happen to be the more expensive parts). thanks for any info!

edit: i did find the link to the modded PC power supplies. i'll look into that, but if there is an off-the-shelf option, please tell. thanks!

Are you absolutely persuaded that it's the power supply unit (as opposed to something else)? Faulty RAM may give the same symptoms as you describe.

Are you experiencing power surges where you live? It seems odd to me that a replacement psu should fail after such a short period of usage. The power demand/load you mention shouldn't other a psu one little bit. Those old tower Macs will take a power of punishment (no pun intended).

After having a quick look with Google for replacement parts, the news doesn't appear encouraging. What about buying a replacement G4 (or later) tower computer? I imagine the price, using the online auction process, would be similar, possibly cheaper. See Apple - Support - Discussions - MDD G4 Dual 1.25GHz-2MB L3 - .... Then swap over the hard drive, optical drive, etc.

technically, i have nothing to prove it's the power supply other than the symptom being identical to the last failure. the first time, i literally tried everything. even removed the RAM, replaced one at a time, etc. i actually have two of everything now thanks to ebay and could build another unit with a box and power supply. unfortunately, the power supply is the most expensive going part of this computer.

i don't doubt that the power here is inconsistent. the house was built in the 20's. we haven't had many problems, but i'm thinking hard about a UPS if i do decide to fix this computer.

i just looked at eBay myself. whole working units are selling for cheaper than power supplies alone. makes me wonder what part fails the most...

Do you feel competent to use a multimeter? That way you can test for certain whether or not the psu has failed. Reply for more info about doing that if you wish.

Meantime, assuming you're in the US, check some of these links to used Mac parts.
Macintosh Dealers, Parts & Service
DV Warehouse mac store, Apple macintosh parts, computer systems, LCD display & monitors, Accessories and software.

A UPS within an old house with old wiring is a very good idea.