Friday, November 25, 2016

Apple iMac Intel 20 – Disassembling – How to replace the Power supply

Loosen the single Phillips screw in the center of the access door.
This screw is captive in the access door.
Remove the access door from your iMac.
The glass panel is fixed onto the front bezel with fourteen magnets around its perimeter.
Stick two suction cups to opposing corners of the glass panel.
To attach the suction cups we sell, first position the suction cup with the movable handle parallel to the face of the glass panel. While lightly holding the suction cup against the glass, raise the movable handle until it is parallel with the other handle.
If your suction cups refuse to stick, try cleaning both the glass panel and the suction cup with a mild solvent such as Windex.
Gently pull the glass panel straight up off the iMac.
The glass panel has several positioning pins around its perimeter.
To avoid shearing these pins off the glass panel, be sure to only pull straight up during removal.
Be meticulous about cleaning the
LCD and the inside face of the glass panel before reinstallation, as any fingerprints or dust trapped inside will be annoyingly visible when the display is on. Placing the glass flat, inside face down, on a fresh aluminum-foil surface is a good way to keep it clean.
Remove the following 12 screwssecuring the front bezel to the rear case:
Eight 13 mm T8 Torx.
Four 25 mm T8 Torx.
Disconnect the microphone cable connector, removing tape as necessary.
For the front bezel to sit properly, be sure to tuck the microphone cable and connector into the void next to the camera board.
Pull the LCD temperature sensor connector straight up out of its socket on the logic board.
If necessary, de-route the LCD temperature sensor cable from behind the logic board.
When you remove the LCD, check the routing of the LCD temperature display cable. On reinstalling the display, be sure this cable does not block one of the bottom screws for the front bezel.
Remove the two 5.3 mm T6 Torx screws securing the data display cable to the logic board.
Use the attached black tab to pull the data display cable connector away from the logic board.
Remove the eight 12 mm T8 Torx screws securing the display panel to the rear case.
Lift the display panel from its left edge and rotate it toward the right edge of the iMac.
With the display panel still lifted, disconnect the four inverter cables.
During reinstallation, place the four inverter cable connectors in voids between components attached to the rear panel so the display panel will sit flush.
During reassembly, the order of the inverter cables is interchangeable within each socket.
If you are replacing a hard drive and have an extra set of hands, it is possible to reach in and remove the drive without disconnecting anything but the LCD temp and display connector in the previous step with the LCD in its propped position.
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.
Remove four T10 Torx screws securing the power supply to the rear case.
Two fine-thread 7 mm T10 Torx
Two coarse-thread 7 mm T10 Torx
Rotate the top edge of the power supply slightly away from the rear case.
The single-wire connector near the upper left corner of the power supply is small and held very tightly in its socket, making it inherently difficult to remove. Be sure to pull only on the connector during removal, as pulling the cable will surely cause it to break.
The single wire shown in the first photo is for the power supply temperature sensor. If you have power supply temperature issues after installation, check this connection first.
Grab the connector between the nails on your thumb and index fingers and pull it toward the top of your iMac, disconnecting it from the power supply.
Rotate your power supply toward the optical drive.
Disconnect the DC power cable by simultaneously depressing its lock mechanism and pulling the connector away from its socket.
It may help to wiggle the connector while pulling it away from its socket.
Disconnect the AC-in cable by simultaneously squeezing the cable lock and pulling the connector away from its socket.