Use an external monitor to determine if a display issue is caused by the LCD/cable or a failing graphics card/motherboard.

Detailed, step-by-step guides are available from iFixit and PowerbookMedic .

A black display does not always mean a bad LCD or GPU; a broken video signal connector on the LCD can prevent the backlight from turning on entirely.

Use suction cups to pull the glass panel away. It is held by magnets.

T6, T8, and T10 are necessary for most internal components.

Use a soft, non-abrasive surface to protect the glass and display when removed. Key Disassembly Steps

Are you planning to perform a specific , such as installing an SSD or replacing the graphics card? Apple Technician Guide iMac (27-inch, Mid 2010) - tim.id.au