Tag: imac

Buzzing noise and hard to turn on from iMac 27′

Buzzing Noise from iMac 27'

Got buzzing noise from top left corner, and very hard to turn on, power button may or may not response.

The fan noise also comes from bottom right corner, thinking to replace a new one.


The power button got issue long ago, sometimes can not work, sometimes can. I think after disconnected from power, maybe will be ok later. I thought it could be bottom connection issue.

After moved iMac into a quiet room, I heard buzzing noise from top left corner, I started believe the power supply got issue.


Replace power supply later together with fan.


IMAC Buzzing Noise From Top Left Corner FIXED!! / Replace Power Supply

iMac 27″ Video Card Repair Using Heat Gun

iMac 27" Video Card Repair Using Heat Gun

Refering to some YouTube video, I tried to repair my iMac 27" (Mid 2011) Video Card, because my iMac could not boot and only apple logo appears. Steps as below

Hardware Info

Identifier iMac12,2
Model A1312 (EMC 2429)
Family iMac (27-inch, Mid 2011)
CPU 3.4 GHz Intel Core i7
Graphic AMD Radeon HD 6970M 2048 MB


Take out glass panel

Use sucker to take it out.

Take out screen

Got 8 screws.

Take out power supply

Power Supply Cable Connectors

Power Supply Screws

Left of Power Supply

Take out CDROM Drive

CD Drive

CD Temperature Sensor

Take out fan


Fan (no screw)

Take out main board

Mainboard Battery

Mainboard Screws

Mainboard Below Fan

Below Fan

Below Fan Cables



Mainboard Wifi


Speaker Cable

Speaker Connection

Just for info


Take out main board back cable

Mainboard Back

Mainboard Back Unplug

Take out video card

Video Fan

Right Top Video Card


GPU Back

GPU Heat Sink

GPU Heat Sink Screws

GPU Screws

GPU no Screw


The video card to LCD screen cable damaged, bought new one, waiting for delivery.

Damaged Cable

LCD Cable

Working now

Oct 13, After purchased cable, replace it, works immeditially, then continue OS reinstallation.

Future use

Due to this machine is too hot, I think better only use it in aircon room, and no background service should be executed.


My iMac is different model as below, but similar.

A1312 iMac GPU Replacement
Late 2009 iMac 27" Video Card Repair — 4850 — 2nd Bake