Power Mac G4 MDD - Won't power up

Interesting everyone is having same issue at the same time. I also had the date/time issue with that machine.
This morning, my MDD wouldn't boot. The power button seems to be the issue.

I had been unplugging the power cord and replugging it in for the last 6-10 months. That worked, until this morning. Seems to me, I replaced the Pram battery 15 months ago (maybe sooner). The drives are OK, I'm sure...but pulling them and getting the data off is a pain and time consuming. Not to mention couldn't have happened at a worse time.

I did a back up about 1 month ago, so I have most of my data-- just not the last month's worth (which shouldn't be that much, but annoying just the same.)

Maybe the thing to do is buy one of those HD adapters from OWC and just pull all the data off onto another drive. Then burn the DVD for the required data.

If anyone is able to get their machine working, please post what you did.
Really annoyed now...

Not sure why editing isn't working...

Anyway, saw a guy's message on one of the other boards.. He figured out it was a fuse on the power supply. He had all the same symptoms.. Once he replaced the fuse, he was all good. A lot cheaper than buying power supply.
I will try this this weekend.

http://discussions.apple.com/thread.jspa?messageID=8422935

Mine does the same. I have read about the FPS (Front Panel Switch) I think it's a circuit board that also ties into the sleep/wake function. I am going to research the FPS and see if obtaining another may be the solution?

See my post of Dec 12 above for a possible way to diagnose the FPB using an old iMac keyboard.

I just encountered the same issue with an MDD PowerMac. The power light would turn on when I would press down the power button, but it would go out once I let up on the button. No whirring fans, no chime -- nothing.

I then took out the 3.6V battery on the motherboard, and the computer started up! Go figure. I then stole a 3.6V battery from another PowerMac G4 and popped it into the MDD PowerMac. Seems to work OK, I just had to reset the time on it.

I then stole a 3.6V battery from another PowerMac G4 and popped it into the MDD PowerMac. Seems to work OK,

Yep, those little batteries are important. With a house full of Macs, I always have 3-5 fresh ones in the veggie drawer of the frig for emergencies.

Leaving the computer connected to wall power all the time greatly extends the PRAM battery life, so you avoid the unpleasant surprises.

I was able to get my hands on an old g4 and im trying to get the thing to boot but am having some issues.

It did not come with a harddrive, or a power supply. i picked up a matching power supply pulled from another g4 off ebay (model api1pc12), and a new pram battery. i currently don't have a spare harddrive for it, but it doesn't seem to be fully turning on. when the power is plugged in and i plug in a monitor via vga, the monitor makes some static noise, as if its preparing to show an image, so it recognizes that its being plugged into a graphics card.
however, when i hit the power button, nothign really happens. i opened the latch to see what was going on. the fan starts spinning up, and a red light on the motherboard shines bright. when i plug in the optical drive, it makes an additional noise on startup, but i am unable to get the drive to eject the tray so i can put in a mac os x install disc. iv'e tried putting my laptop in target disk mode, and then booting the g4 with option down - so i can select the laptop as a boot source, but nothing shows up on the plugged in monitor. i have a feeling that the supply works, but there is another issue. could it be that the motherboard is faulty? maybe the graphics card? there seems to be an older rage card installed as well. there is also a single 512mb ram chip. doesn't really seem like anything is missing beside the harddrive, but what stumped me was that when i plugged in a drive i know is fried (makes the clicking noise in an external case), on boot, i don't even get that. is power even running through the motherboard? im pretty sure i plugged everything in correctly - power to the board, power to the fan, power to the optical, power to the harddrive, and ran the ide cable to connect to the optical, and the ata coming form the mother board to the harddrive.

im not getting any startup chime, but the light does shine behind the power button. plugging in a keyboard and hitting the power on the keyboard seems to turn the machine on as well.

really looking forward to getting this thing working, so all help is greatly appreciated. i can post pictures of the insides if that will help (unless somebody knwos the issue off the bat).

thanks!

I have a G4 Digital audio (dual 533) and started to receive the date error message over the past few months. I got a replacement battery, but upon getting someone to test this for me it seems it only has 3.1 V. Can I assume this is not high enough ? I presume so, and will be contacting the supplier for a replacement. Once I get the new one, I unplug everthing, insert the new battery, wait for 30 secs, press the PMU briefly, then power-up - correct ??

Also, trying to be energy efficient, I have started to fully unplug the machine each evening from the mains power. Is this something I should not do ? I seem to see in some threads that this can shorten the life of the PRAM battery.

Thanks,
Peter

I have been having identical problems to what everyone has been discussing. I was just about to fork out the dough for a new power supply and I tried one last thing. I hooked up my lucite monitor directly to the back of the computer and tried using the power button on the monitor. Bam! Computer started and has been working fine ever since (knock on wood). Just thought I'd put this in here in case I can save others the frustration that I've been through