G3 powers on but ONLY with Orange light and completely Black screen! HELP!

I had that problem but i had to change the logic board for mine to work again as it wouldnt turn on either just the orange light lol so its either the logic board is bad or there is a problem with the video board but mine fixed with a different logic board

I've restored and donated around 50 iMacs and have yet to see a bad logic board in a slot loader. Tray loaders yes, have a few of those.
Is this a slot or tray loader? ie the CD loads thru a slot or a tray that slides out.
Does it have firewire? (Two slots on the same side where the USB ports are that look like elongated pentagons)

Here's the service manual on a logic board reset:
"Resetting the PMU on the Logic Board
Resetting the PMU (Power Management Unit) on the logic board
can resolve many system problems. Whenever you have a unit that fails to power up, you should follow this procedure before replacing any modules.
1. Disconnect the power cord and check the battery in the battery
holder (BT1). The battery should read 3.3 to 3.7 volts.
If the battery is bad, replace the battery, wait ten seconds, and then reset the PMU (refer to the next step). If the battery is good, go to the next step.
2. Press the PMU reset switch (S1) once on the logic board and then proceed to step 3. Do
NOT press the PMU reset switch a
second time because it could crash the PMU chip.
3. WAIT ten seconds before connecting the power cord and powering the computer on. If the computer powers on, go to the next step. If the computer does not power on, there is something else wrong with the computer, refer to the symptom/cure chart, “No Power” in this chapter."

eMail me for more info.

Richard

Your best bet would be to look on ebay i got mine from there as the supplyer in the uk i looked up from google wanted £300+ for a used one. But i would try google first

OK it's a tray loader. They came in speeds of 233, 266 and 333
MHz. Here's a reset procedure of the CUDA chip:
Resetting the Logic Board
Resetting the logic board can resolve many system problems (see
the Symptom/Cure tables for examples). Whenever you have a
unit that fails to power up, you should follow this procedure
before replacing any modules.
1. Unplug the computer.
2. Disconnect the cable that runs from the power supply to the
power filter board on the bottom side of the logic board/mass
storage chassis.
3. Press the Power On button on the front of the unit.
4. Remove the logic board/mass storage chassis from the unit.
5. Remove the battery from the logic board.
6. Wait at least 10 minutes before replacing the battery.
7. Make sure the battery is installed in the correct +/-
direction.
8. Reassemble the computer and test the unit.
Note:
This procedure resets the computer’s PRAM. Be sure to
check the computer’s time/date and other system parameter
settings afterwards.

Try that and let me know.

If you need a manual on how to take the iMac apart email me.

Richard

and before you do the above try resetting the Cuda chip (misspoke myself above):
Many system problems can be resolved by resetting the Cuda chip (see the Symptom/Cure tables for examples). Press the Cuda reset button on the logic board to reset the Cuda chip. (The Cuda reset button is located on the back edge of the logic board between the modem port and the processor module. Refer to the Logic Board Diagram in the Basics chapter for location information.) If you continue to experience system problems, refer to “Resetting the
Logic Board”
Which is my earlier post.
Richard

All the tray loading iMac g3's, models a-d, are constructed the same.

Here is a good disassembly page:
http://www.macopz.com/columns/imacrepair/disassembly.html

The second article in this series has information on replacing the battery:
http://discussions.apple.com/thread.jspa?messageID=2584291

If you upgrade to OS X...

You should verify that you have the latest firmware, before installing new software. See the system profiler for details. What firmware do you need?
http://docs.info.apple.com/article.html?artnum=86117

You may run Mac OS 10.3 on this machine. Apple Macintosh Operating Systems & Technical Manuals, see:
http://www.applerescue.com/
Mac OS X takes about 4gig.

This will require a minimum of 128meg of ram. More is better. I'd suggest 256. The revision A mac's are limited to 384 meg of memory. The b-d models, you may put 512meg of ram in this machine. There are two memory slots. One must be Low Profile memory. Be sure you can return your memory cards. iMac memory cards are finicky.
http://eshop.macsales.com/shop/memory/iMac-G3-G4/

Robert

I've got a similar problem with my brother's iMac G3 (five flavors). When turned on it makes a sound akin to the death chimes on old beige Macintoshes, the orange light doesn't go green and the screen doesn't turn on. I am currently in the process of pulling the iMac to reset the PMU and I am yet to find out if it has worked.

Has anyone else come across such a problem? Any suggestions on how to fix it? And how to prevent it from happening again because it has refused to start up before.

PowerBook G4 Mac OS X (10.4.10)

Hmm it's right there on my ID. should work.
Richard