It's been quite some time since I workedon a G3 iMac, but here are a couple of suggestions. Check the Master/Slave settings for HD and CD-drive. If I recall correctly, the hard drive from the G4 (which was in the iMac when the lightning struck had a different setting than the hard drive that was originally in the iMac, and now back in the iMac). If I recall correctly, I once took a HD out of an iMac DV, and put it into a fruity iMac, and I had to change the pin settings for that drive to work in the older version iMac. Perhaps you changed the settings when you put the G4's HD in the G3 iMac, and now you need to change the settings back when you returned the original drive.
Next suggestion:
Did you try to boot the iMac from its original install disk, or from the OS 10.3 disk you originally updated it from?
If it boots from the CD, maybe the old HD you put in is also bad.
Here are some excerpts from the Service Source iMac G3 Tray Loading Manual:
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.)
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.
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Power-On Self Test
There is a power-on self test that resides in the ROM of the iMac. This test automatically runs whenever the iMac is powered on after being fully shut down (the power-on self test does not run if the machine is only restarted).
If a problem is detected during the test, you will not hear a normal startup chime. Instead, the system will beep as explained below. Refer to “Error Beeps” later in this chapter for instructions on how to troubleshoot and repair an iMac that sounds error beeps at startup time.
Following is a definition of what the error beeps at startup time signify.
• 1 Beep: No RAM is installed or detected.
• 2 Beeps: EDO memory is installed. (The iMac ships with SDRAM SO-DIMMs and does not accept EDO memory).
• 3 Beeps: No RAM banks passed memory testing.
• 4 or 5 Beeps: Bad checksum for the remainder of the boot ROM. The ROM (which is located on the processor module) is bad.
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System Hangs/Freezes During Boot
1) Boot with Extensions off by holding down the Shift key during startup. (See TIL article #14343 for more information on possible Extension conflicts.) Does the system startup successfully with Extensions off?
Yes: Begin adding back the system Extensions one at a time and starting up the system after each addition. If the system freezes again, you know that the last Extension you added is causing the problem.
No: Go to the next step.
2) Boot from the system CD that came with the unit. Does the system startup successfully? Yes: Reinstall system software. (You must use the system software CD that came with the unit to get the correct version of Mac OS .) If the problem persists, go to the next step. No: Reseat the SDRAM. If the problem persists, replace the SDRAM (one DIMM at a time) with known- good SO-DIMMs.
3) Bad USB device. Turn off the computer and disconnect all USB devices. Next, power on the system using the power button on the front of the unit, and begin adding back the USB device one at time, beginning with the keyboard and then the mouse, and so on. If the system hangs only after you reconnect a particular USB device, replace that USB device.
4) The hard drive or its software drivers are most likely the problem. Can you see the hard drive using Drive Setup?
Yes: Use Drive Setup 1.5.1 to reinstall the software drivers for the hard drive. If the problem persists, use Drive Setup 1.5.1 to reinitialize the hard drive (See TIL article #22206 for Drive Setup information.)
±Warning: You will lose all data on the hard drive when you reinitialize it. Backup the data first if possible.
No: Go to next step.
5) If you don’t see the hard drive using Drive Setup:
- Check all cable connections to and from the hard drive. - Replace the hard drive/CD data cable. - Replace the hard drive. - Replace the hard drive power cable
6) Disconnect all external devices (USB and Ethernet). Then begin reconnecting these devices one at a time (beginning with the keyboard and then the mouse) and start up the computer after each device is connected to see if one of the external devices is causing the problem. If the problem occurs after you connect a particular external device, replace the device in question.
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Good luck.
