iFixit - Answers With Device "iMac G4"

iMac G4 15" 700 MHz EMC 1873: Help I accidentally disconnected the Tmds cable

Tue, 20 May 2025 06:29:45 -0700

I was working on it and the grounding cable or something got torn off of the board and the frame around it came off halfway.

I could probably solder it but this came off and i need help. not disconnected. it did not damage the board though so it may not be as bad

⟐ Commented May 20, 2025 at 6:29 MST

iMac G4 15" 700 MHz EMC 1873: Trying to reinstall OS

Sat, 28 Dec 2024 16:40:21 -0700

Hello everybody (again).

I previously posted about a fault with my g4 not turning on, which has now been sorted. But now I'm faced with another problem!

I bought it from eBay, faulty and the fault has been sorted. But now I don't have the login password and I'm having trouble reinstalling the OS. I have all of the original discs but when I insert the install disc and hold C nothing happens, it just loads up to the login screen. I'm using a Windows keyboard but that's never been a problem in the past. My guess is a faulty CD drive but before replacing that I was wondering if anybody has any tips for me? Maybe a way of creating a usb drive that I can install the OS from? Or another idea is to install the OS on an external drive and clone it to the internal drive, but I'd need directions on how to do this. I have plenty of iMacs and Macbooks lying around if that helps?!

I'd love for an answer to my problem as its in brand new condition and has every piece of original packaging, etc..

Thanks in advance

⟐ Commented December 28, 2024 at 16:40 MST

iMac G4 15" 700 MHz EMC 1873: New Display Mounts for G4?

Tue, 20 Aug 2024 16:05:42 -0700

What if I want to use a newer display panel so it has better quality and has, say, IPS and HDR? How do I get a mount, etc., to get it to fit?

iMac G4 17" Model M9168LLA: Problems with my 2 iMac G4

Sat, 03 Aug 2024 11:03:05 -0700

Hello,

I have inherited seven iMac G4s, two of them 17 inches.

As I don't have much experience in computer repair, I would like your advice.

The first, when I plugged it in, there was only the ventilation as a sign of life, so I unplugged it and dismantled it.

I removed the two ram strips to see if that would change anything, then I removed the non-essential internal peripherals (hard disk, cd drive).

All my manipulations didn't change a thing, the result was the same as at the start, simply a black screen and ventilation...

For the second one, I did the same thing, but again, nothing changed.

The symptoms are: when I press the power button, the fan runs for about a second and then nothing after that.

Have a nice day!

Amaury from France

⟐ Answer accepted August 03, 2024 at 11:03 MST

iMac G4: How can I remove the 17" panel shield from the plastic back of display

Sat, 13 Apr 2024 17:32:31 -0700

The Service Source book for the iMac G4 (imac_usb2-updated.pdf) covers both the 15" and 17" display sizes. It describes how to remove the panel shield for the 15" display, but not the 17" panel shield that is held in entirely differently - many small, plastic catches all around the metal shield. What is the trick to remove it without breaking the plastic back of the display housing?

⟐ Commented April 13, 2024 at 17:32 MST

iMac G4 17" Model M9168LLA: iMac G4 17" 1.25 GHz DEAD. Help me, please.

Wed, 14 Jun 2023 04:16:58 -0700

After some years, I decided to switch on my old and beautiful iMac G4 17" 1.25 GHz. No signs of life. I tried to disconnect all cables, hold power button for 10 seconds and replug the power cord. No sings of life. I tried to press ONCE the PMU button (close to ariport slot). No sings of life. I tried to replace the little battery inside (close to RAM slot). Still no sings of life... Any ideas?! Thank you so much!

⟐ Commented June 14, 2023 at 4:16 MST

iMac G4 17 800 MHz EMC 1936: iMac will not fully boot

Sun, 07 May 2023 19:49:08 -0700

I have either the original or 2003 model of iMac G4. The base plate says 800MHz/60/256 and it uses the older airport card.

I got this in a lot of other Macs and don’t know the background. I cannot get the machine to boot. I have replaced the PRAM battery as well as pressing the reset button that is next to the airport card.

When plugged in and I press the power button, the fan will kick on for a second and shut back off. There is also a red light that appears under the iMac near the airport card for the same duration of a second and shut off.

Not sure what else to check. I’ve removed both RAM cards as well as trying each individually with the same result of only coming on for a second.

There are no other lights and no tones indicating bad RAM or other post issues

⟐ Commented May 07, 2023 at 19:49 MST

iMac G4 17 800 MHz EMC 1936: Fan not spinning up after replacement

Thu, 27 Apr 2023 18:08:29 -0700

I was working on replacing the loud and old fan on my iMac G4. I cut off the connector of the old fan, and determined the polarity as follows:

Cable color iMac → corresponding cable on replacement fan (Arctic F9):

Black → striped black cable

Red → middle cable

Yellow → outer black cable (not striped)

When connecting the old fan like this to a USB adapter, it spins up. Installed in the iMac, the new fan doesn‘t spin up and isn‘t „detected“ by the OS (10.4.11). How can i go about testing the polarity of my cables is correct? I do have a multimeter available, i just don‘t know what to measure.

⟐ Commented April 27, 2023 at 18:08 MST

iMac G4 15" 700 MHz EMC 1873: Why can I not clone the hard drive?

Thu, 21 Jul 2022 09:30:12 -0700

I have 2 iMac G4s, one 15-inch, and the other 17-inch, I need to clone one of their hard drives to make the other one work. I have a USB HDD converter. When I go to disk utility and copy the hard drive, I very soon am greeted with an error saying that this task is impossible. Does anyone know what might be the cause of such a malfunction?

⟐ Answered July 21, 2022 at 9:30 MST

iMac G4 17" Model M9168LLA: Why is my iMac G4 not powering up (after a power outage)?

Fri, 20 May 2022 05:53:56 -0700

Hi,

Our imac G4 is not powering up after a power outage during the night. It is connected to a surge protector. Other devices, connected to the same surge protector are working. We have tried the following:

1. turn off switch, unplug from surge protector, replug, turn on.

2. Take out power cord from the mac, and press the "on" button simultaneously while putting the power cord back in the mac. We waited for 10 seconds but nothing happened.

No sounds/smells.

Please help!

Thanks,

Barna

⟐ Commented May 20, 2022 at 5:53 MST

iMac G4 15" 700 MHz EMC 1873: Where is PMU reset button?

Sun, 28 Nov 2021 14:21:15 -0700

Computer will not turn on, tried shift/option/command, doesn't work. was told to try to reset the PMU on logic board.

⟐ Answered November 28, 2021 at 14:21 MST

iMac G4 15" 700 MHz EMC 1873: Will an 800 mhz board fit in a 700 mhz model?

Wed, 24 Nov 2021 13:20:03 -0700

I am in need of a logic board replacement and I am wondering if an 800 mhz logic board will fit or be compatible with my (currently) 700 mhz imac g4 15”, or will i need to just get another 700 mhz board. also, if anyone can, is there a site that has these parts that is low enough in cost.

Thanks!

⟐ Answer edited November 24, 2021 at 13:20 MST

iMac G4 15" 700 MHz EMC 1873: How to bypass putting in a password

Thu, 18 Nov 2021 15:42:20 -0700

I got one of these out of e waste, and decided to restore it. it works fully and the previous owner’s info is on there. I am wondering, is there is a way to bypass or reset the computer’s password so that i have full access to the computer?

also to mention i have a windows keyboard so what i can do on the mac may be limited by the keyboard.

⟐ Answer edited November 18, 2021 at 15:42 MST

iMac G4 15" 700 MHz EMC 1873: iMac G4 won't turn on. Led blinks in a pattern long-short.

Mon, 15 Nov 2021 09:16:09 -0700

I just bought a vintage Mac, an iMac G4. It won’t turn on. The led blinks in a repeated pattern of “long-short”. Any ideas how to resolve it?

iMac G4 17" Model M9168LLA: iMac G4 not connecting to WiFi

Tue, 02 Nov 2021 14:09:32 -0700

I have two iMac G4, both 20-inch models, PowerMac6,3

One is running Mac OS X Leopard which connects to the WiFi just fine.

AirPort Extreme, Locale: Unknown, Firmware: Broadcom BCM43xx 1.0

My second G4 is running Mac OS X Panther which detects all the available networks but it doesn’t connect to any even when the password is correct.

AirPort Card Information…

Wireless Card Type: AirPort Extreme

Locale: Worldwide

Firmware: 3.2GMc1

Current Wireless Network: wireless network not available

Modem Information…

Firmware Version: APPLE VERSION 2.6.1

Driver: InternalUSBModem.kext (v2.6.1)

Modem: Dash2 (V.92) Australia 1.0F

Country: 9 (Australia)

Interface Type: USB

I read in another post that G4 does not recognise WPA2 and I might need to change my router setting to WPA. But then how come one works and the other one doesn’t?

⟐ Commented November 02, 2021 at 14:09 MST

iMac G4: Cursor refuses to move

Mon, 13 Sep 2021 07:13:50 -0700

On start up the cursor remains unloveable in top left

⟐ Answered September 13, 2021 at 7:13 MST

iMac G4 15" 700 MHz EMC 1873: iMac g4 won't boot up and weird screen when it cans

Mon, 03 May 2021 13:31:22 -0700

Hello, recently a school gave me an imac g4 that was used for educational purpose and the school said that the mac was dead. So i first pluuged the power outlet and it booted but with a weird screen changing to completely white. A few weeks ago and yesterday, i just replugged it to test the mac but now, the mac won’t boot up, no fan nothing. Only a fast clicking sound coming from the power supply that stops sometimes after a few seconds. I dissasembled all the imac and look for any damage on the mac. With a multimeter i checked the voltage coming from the first power supply board and i got 400 v continue but on the second board, i have no voltage. Have you got any tips to look for maybe shorted parts or capacitors that usually break up in these machines ? Thanks for help

⟐ Commented May 03, 2021 at 13:31 MST

iMac G4 15" 700 MHz EMC 1873: iMac G4 won't boot, fan twitches

Wed, 21 Apr 2021 08:20:54 -0700

Alright guys, so I'm having some troubles with an old flowerpot iMac. About a month ago I knocked a glass of water on the desk where the computer is sitting. There was no splash to speak of, the water just spilled around the base of the iMac. I immediately pulled the plug, but didn't feel like doing much more, as it was 3AM. Anyway, I left it like that for over a week before plugging it back in and trying to turn it on. Well, it didn't boot. I was kind of surprised because it was a relatively small amount of water and I didn't think it would get inside from under the base.

Now, I'm far from an expert, so I did some Googling and tried resetting the PRAM on the switch on the motherboard to no avail. I also checked the CMOS battery, which seems to still have power in it. Today, I decided to take apart the iMac for the heck of it. I cleaned it to the best of my capabilities and reseated the RAM. Tried turning it on while it was taken apart and noticed that the fan twitches when I plug it into an outlet. Nothing happens when pressing the power button. I don't see any blown capacitors on the motherboard or psu. I tried turning it on without the HDD and optical drive connected, just in case, and again the fan twitched when I plugged it in.

Any help is appreciated!

Edit: Here's the base and both sides of the motherboard. I don't see anything around the vent holes, save for a bit of dust.

Edit 2: Alright, so the photos got scaled down while uploading. Here's a Google Photos album with the full-size images: https://photos.app.goo.gl/TiF1wUOPPoC3OI...

⟐ Commented April 21, 2021 at 8:20 MST

iMac G4 17" Model M9168LLA: iMac G4 Stuck On Black Screen

Fri, 05 Mar 2021 10:02:01 -0700

I was given a 17’ iMac G4. I powered it on and played around on it. Then I shut it down and moved it to another room, and it has not powered back on correctly since.

When I press the power button, I hear the startup chime and hear the computer running, but the screen does nothing. I’ve ruled out screen damage because it boots to open firmware when I hold Command + Option + O + F. I have tried A PRAM reset, and I’ve tried pressing the PMU reset button on the bottom.

My question is, what could be wrong with it? How do I fix it? Why was it working one moment and then not doing anything the next?

I really appreciate any help you can provide.

⟐ Edited by author March 05, 2021 at 10:02 MST

iMac G4: replace inverter board on iMac g4 17"

Sat, 06 Feb 2021 10:35:17 -0700

I need to replace inverter board but not sure just what it looks like.

⟐ Commented February 06, 2021 at 10:35 MST