iMac G3 Model M4984 Video Ram Replacement

The iMac G3. This was a great computer for the time, and had plenty of features.

Start by flipping the iMac upside-down. It may help to lay it on a towel, so you don't damage the screen, or scratch the face.

Remove this Phillips screw.

Using a flathead screwdriver, work your way around the bottom cover, until it comes off.

Then, lift the bottom cover up and out, and set it aside.

Now, remove the DB-15 Video connector from the logic board.

It may be helpful to use a Phillips screwdriver to remove the thumbscrews.

Remove the power cable from the logic board assembly.

Remove the front panel connector. (You may also need to remove an additional screw that connects the front panel connector to the logic board assembly).

Now, remove these Phillips screws.

Now, grab the logic board assembly by the piece of plastic, and lift it out.

The logic board assembly. This is the heart of the computer, it contains the motherboard, CPU, RAM, V-RAM, PRAM battery, the hard drive, and the optical drive.

The Video-RAM DIMM slot is located on top of the logic board. Most people confuse this with the system RAM which is hidden under the CPU Shield.

The GPU: an ATI 3D Rage Pro Turbo PCI with 2MB onboard + the video RAM DIMM:

The Video RAM DIMM:

To remove the V-RAM, push the retaining tabs out, and the DIMM should pop up, then pull it out.

The 2MB of V-RAM soldered to the logic board:

According to what I've read, the iMac will support 10MB Total V-RAM, 2MB onboard, 8MB DIMM.