Sunday, December 18, 2016

Apple iMac G5 17 – Disassembling procedure – How to replace the power supply

Before you work on the computer, unplug the computer and press the power button for 20-30 seconds to drain the stored energy in the power supply.
Loosen the two Phillips screws securing the access door to your iMac. These screws are captive in the access door.
Remove the access door from your iMac.
Remove the three T8 Torx screws securing the front bezel to the rear panel.
Orient the iMac face-up, on its backside.
Use your thumbs to press both RAM arms in past the front bezel for enough clearance to lift it off the rear case.
While holding the RAM arms in with your thumbs, lift the lower edge of the front bezel enough to clear the rear case.
Re-orient your iMac so it sits upright on the stand.
Insert a plastic card up into the corner of the air vent slot at the top of the rear case.
Push the card toward the top of the iMac to release the front bezel latch.
Pull the front bezel away from the rear case.
Repeat this process for the other side of the front bezel.
It may be necessary to apply several layers of duct tape to the top of the access card to aid in releasing the latches.
If the bezel refuses to release, try pressing the lower edge back onto the rear case and repeat this opening process.
Lay your iMac stand-side down on a table.
Lift the front bezel from its lower edge and rotate it away from the rest of your iMac, minding the RAM arms that may get caught.
Lay the front bezel above the rest of the iMac.
If necessary, remove the piece of kapton tape wrapped around the microphone and camera cables.
Disconnect both the camera and microphone cables.
Peel back the aluminum EMI shield up off the lower three edges of the rear case.
It is not necessary to peel the EMI shield off the display.
We found it helpful to tape the EMI shield up against the display to keep it out of the way.
Remove the two 5 mm T6 Torx screws securing the display data cable to the logic board.
Using its attached black tab, pull the display data cable connector up off the logic board.
Pull the inverter cable connector up off its socket on the logic board.
Peel back the aluminum EMI tape from the two vertical edges of the display.
During reassembly, it is helpful to use several small strips of tape to hold the EMI shielding along the left and right edges of the display footprint out of the way before lowering the display into the rear case of your iMac.
Remove the four recessed coarse-thread 7.5 mm T10 Torx screws securing the display to the rear case.
These screws are recessed, so a thin screwdriver such as this is essential for removal. Bit drivers tend to be too short for this application.
Lift the display from its lower edge and pull it toward yourself to peel it off the EMI shield attached to its top edge.
Be mindful of any cables that may get caught during removal.
Disconnect the hard drive thermal sensor by pulling the connector away from its socket parallel to the ace of the hard drive.
Pressing the top of the hard drive bracket down to release it from the rear case requires a substantial amount of force, so we recommend laying your iMac stand-side down on a table to avoid knocking it over.
Press the hard drive bracket down toward the bottom edge of your iMac to free it from the rear case, then rotate the top of the drive toward yourself.
Lift the hard drive off its lower pins and pull it out of the rear case, minding the cables that are still attached.
When reinstalling the hard drive, be careful not to push the rubber grommets through the chassis with the hard drive pins as retrieving them may require logic board removal.

Insert the flat end of a spudger into the gap between the SATA power connector and the hard drive.
Twist the spudger to separate the SATA power connector from the hard drive.
Pull the SATA power connector away from the hard drive.
Pull the SATA data cable away from the hard drive.
Hard drive remains.
The next few steps bring your hands close to the exposed face of the power supply. Do not touch the face of the power supply to avoid a high voltage shock from the many large capacitors attached to the board.
Pull the power supply cable connector away from its socket to disconnect it from the DC to DC board.
Wiggling the connector while pulling it aids in removal.
Use a pair of tweezers to pull the AC-in cable out from underneath the chassis.
Disconnect the AC-in cable by depressing the lock mechanism while pulling the connector away from its socket.
Remove the four T10 Torx screws securing the power supply to the rear case.
The fine-thread screw belongs in the lower right corner of the power supply. When reinstalling the power supply, install the fine-threaded screw first.
Lift the power supply out of the rear case, minding the AC-in cable that may get caught.
Do not touch the face of the power supply board to avoid electric shock.