iMac G5 20" Model A1145 PRAM Battery Replacement

This guide will show you how to replace your iMac's PRAM battery.

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Edit Step 1 Access Door  ¶ 

  • Orient the iMac face-side down on a table with the bottom edge facing yourself.

  • Remove the two Phillips screws securing the access door to the bottom grille of your iMac.

  • The screws are captive in the access door.

  • Before beginning the repair, unplug the computer and press and hold the power switch for 20-30 seconds, to discharge internal capacitors.

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Edit Step 2  ¶ 

  • Remove the access door.

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Edit Step 3 Front Bezel  ¶ 

  • Remove the three T8 Torx screws securing the front bezel to the rear case along the lower edge of the iMac.

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Edit Step 4  ¶ 

  • Turn the computer over.

  • Use your thumbs to press both RAM arms in past the front bezel for enough clearance to lift it off the rear case.

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Edit Step 5  ¶ 

  • While holding the RAM arms in with your thumbs, lift the lower edge of the front bezel enough to clear the rear case.

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Edit Step 6  ¶ 

  • Re-orient your iMac so it sits upright on the stand.

  • Insert a plastic card up into the corner of the air vent slot near 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.

  • Alternatively, you can use a strong magnet by holding it to the front top left/right corner of the display. You will hear a snapping sound when the hatch is released.

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Edit Step 7  ¶ 

  • 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.

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Edit Step 8  ¶ 

  • If necessary, remove the piece of kapton tape wrapped around the microphone and camera connectors.

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Edit Step 9  ¶ 

  • Disconnect both the camera and microphone cables.

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Edit Step 10 Display  ¶ 

  • Remove the two T6 Torx screws securing the display data cable connector to the logic board.

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Edit Step 11  ¶ 

  • To disconnect the display data cable, grab its connector's black tab and pull it away from the face of the logic board.

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Edit Step 12  ¶ 

  • Peel back the two EMI tape strips from the left and right 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.

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Edit Step 13  ¶ 

  • Remove the four recessed T10 Torx screws securing the display to the rear case.

  • Bit drivers tend to be too short to reach these screws. Be sure to have a magnetic thin-shafted T10 Torx screwdriver on hand.

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Edit Step 14  ¶ 

  • Lift the lower edge of the display slightly out of the rear case.

  • Disconnect both inverter cables (shown in red) by pulling their connectors toward the bottom edge of your iMac.

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Edit Step 15  ¶ 

  • Lift the display until it is nearly perpendicular to the rear case.

  • Disconnect the remaining two inverter cables (shown in red) by pulling their connectors toward the top edge of your iMac.

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Edit Step 16  ¶ 

  • While holding the display perpendicular to the rear case, pull it upward to peel off the EMI shield stuck to its upper edge.

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Edit Step 17 Logic board  ¶ 

  • Disconnect the IR board cable by pulling its connector away from the socket on the IR board.

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Edit Step 18  ¶ 

  • Remove the two T6 Torx screws securing the IR board bracket to the IR board.

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Edit Step 19  ¶ 

  • De-route the IR cable from under the aluminum heat sink and tuck it behind the optical drive to keep it out of the way.

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Edit Step 20  ¶ 

  • Remove the single T10 Torx screw securing the left speaker to the rear case.

  • The screw for the left speaker has coarse threads.

  • Lift the left speaker out of the rear case and de-route its cable across the logic board.

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Edit Step 21  ¶ 

  • Remove the single T10 Torx screw securing the right speaker to the rear case.

  • The right speaker screw has fine threads.

  • Lift the right speaker out of the rear case, minding the short cable between the speaker and its connector (located slightly above the right speaker).

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Edit Step 22  ¶ 

  • Disconnect the speakers from the logic board by pulling their connector toward the top edge of the iMac.

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Edit Step 23  ¶ 

  • Remove the two Phillips or two T6 Torx screws securing the AirPort/Bluetooth board to the logic board.

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Edit Step 24  ¶ 

  • Use your finger to lift the AirPort/Bluetooth board from its left edge, disconnecting it from the logic board.

  • Lift the board from its left edge only.

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Edit Step 25  ¶ 

  • Use the flat end of a spudger to pry both antenna cable connectors up off the AirPort/Bluetooth board.

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Edit Step 26  ¶ 

  • Disconnect the DC-in cable by simultaneously depressing both locking arms and pulling its connector away from the socket on the logic board toward the top of your iMac.

  • After both locking arms pass their retaining tabs, it is helpful to push the arms toward the top edge of your iMac while wiggling the connector.

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Edit Step 27  ¶ 

  • Disconnect the ambient light sensor by pulling its connector away from the face of the logic board.

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Edit Step 28  ¶ 

  • Disconnect the optical drive fan from the logic board.

  • To aid in removal, it is helpful to use both of your thumbnails to push the ears on either side of the connector toward the top edge of the iMac.

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Edit Step 29  ¶ 

  • Disconnect the IR/camera cable from the logic board.

  • This connector is especially wide and prone to breakage.

  • To aid in removal, it is helpful to use one hand to pinch the cables against a spudger and pull up toward the top edge of the iMac while pulling up gently on the cables with your other hand.

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Edit Step 30  ¶ 

  • Disconnect the optical drive thermal sensor cable from the logic board by pulling its connector toward the left edge of the iMac.

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Edit Step 31  ¶ 

  • Remove the two T6 Torx screws securing the optical drive connector to the logic board.

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Edit Step 32  ¶ 

  • Use the flat end of a spudger to pry the optical drive connector up off the logic board.

  • It is helpful to insert the spudger under the top or bottom edge of the connector and twist to separate the connector from the logic board.

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Edit Step 33  ¶ 

  • Disconnect the CPU fan from the logic board by pulling its connector toward the top edge of the iMac.

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Edit Step 34  ¶ 

  • Disconnect the hard drive thermal sensor from the logic board by pulling its connector toward the top edge of the iMac.

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Edit Step 35  ¶ 

  • Disconnect the hard drive fan by pulling its connector away from the face of the logic board.

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Edit Step 36  ¶ 

  • Disconnect the power button cable by pulling its connector away from the face of the logic board.

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Edit Step 37  ¶ 

  • Remove the two T6 Torx screws near the top of the heat sinks.

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Edit Step 38  ¶ 

  • Remove the following seven screws securing the logic board to the rear case:

    • Three coarse-thread T10 Torx.

    • Three fine-thread T10 Torx.

    • One long coarse-thread T10 Torx.

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Edit Step 39  ¶ 

  • Tuck the RAM arms into the iMac so they rest on the perforated metal grille along its lower edge.

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Edit Step 40  ¶ 

  • Rotate the top of the logic board toward yourself slightly.

  • Pull the right edge of the logic board toward yourself slightly to free the I/O ports from the rear case, being careful not to bend the board.

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Edit Step 41  ¶ 

  • Continue rotating the board toward yourself until you have enough room to reach the SATA connector (shown in red).

  • Insert the blunt end of a metal spudger between the SATA connector and its socket. Twist the shaft of the metal spudger to separate the connector from its socket.

  • Disconnect the SATA cable from the logic board.

  • Lift the logic board out of the rear case by its edges, minding any cables that may get caught.

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Edit Step 42 PRAM Battery  ¶ 

  • Use the flat end of a spudger to pry the PRAM battery (type CR2032) out of its housing on the logic board.

  • Use your fingers to remove the PRAM battery from its housing.

  • Don't bend the metal retaining clip up too far as it is brittle and easily broken.

To reassemble your device, follow these instructions in reverse order.

For more information, check out the iMac G5 20" Model A1145 device page.

Required Tools

TR8 Torx Security Screwdriver

$5.95 · 50+ In stock

Spudger

$2.95 · 50+ In stock

T6 Torx Screwdriver

$5.95 · 50+ In stock

T6 Torx Screwdriver

$9.95 · 30 In stock

T6 Torx Screwdriver

$4.95 · 50+ In stock

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Comments Comments are onturn off

The PRAM battery is a standard CR2032.

Simon Howes, · Reply

If it still does not release try pressing in and out (like an accordion) with the card in one hand and the screen bezel in the other until it pops loose.

rick, · Reply

My A1145 seems to be attached, somehow, on the top via some silver looking strips. It does not seems to want to come off. Is that the wireless?

Chris Arnold, · Reply

Steps 17 and 18 are not strictly necessary if one simply props up the LCD display into a vertical position while the hard drive is removed and replaced. It worked for me anyway!

I would like to send out a big thank you to Andrew Bookholt for submitting this extremely helpful guide!

Mark Orwoll

Mark Orwoll, · Reply

Prop the screen with something soft (plastic or wood) so as not to scratch the screen coating.

Mark, · Reply

If you are changing the power supply - this is a good point to remove the screws to the old power supply to see if the connectors (both of them) are accessible. If you can gently (but firmly) pull the power connector out from under the chassis, you can install the new unit at this step - saving hours of work.

philaro, · Reply

See note to step 44 to easyly remove the power supply without dismantling the whole computer (as also suggested by philaro).

danman, · Reply

Two T10s are reversed. The bottom T10 to the right of the RAM should be fine-thread. The one directly above it should be coarse-thread.

mike, · Reply

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