Hard Drive

Flashing question mark, or an alternating question mark and Mac OS (face or a folder) Note When troubleshooting hard drive problems it is a good idea, if possible, to back up any important data. Some troubleshooting steps may require erasing the contents of the hard drive. 1. Boot from the system CD that came with the computer, and open Disk Utility. Does the hard drive show in Disk Utility Yes Run Repair Disk and Repair Permissions to correct any directory and permissions issues. Go on to Step...

Display

When displaying a single color over the screen area, the LCD panel shows one or more pixels that are not properly lit Active-matrix LCD technology uses rows and columns of addressable locations (pixels) that render text and images on screen. Each pixel location has three separate subpixels (red, green, and blue) that allow the image to be rendered in full color. Each subpixel has a corresponding transistor responsible for turning the subpixel on or off. There are typically millions of these...

LED

Indicates that the computer and the LCD display are communicating. This LED will be ON when the computer is turned on and video signal is being generated. Indicates that the computer has power but no video signal (e.g., the computer is starting up or the display has entered Sleep mode, turning off the video signal). This LED will pulse when the entire system has entered Energy Saver mode.

Removing the Clutch

Carefully peel the three pieces of EMI tape up and off the metal clutch cover. 3. Using a T10 torx screwdriver, remove the four clutch mounting screws. 3. Using a T10 torx screwdriver, remove the four clutch mounting screws. 4. Stand up the unit and remove the four T10 clutch-to-stand mounting screws. Separate the clutch from the rear housing and the stand.

Warning High Voltage

Disconnect the AC power inlet connector on the left and the power supply-to-logic board connector on the right. Note The power supply connector is on the underside of the logic board. See the next photo for another view of the connector underneath the logic board. 2. Rotate the computer so that the stand is away from you. Locate the power supply connector underneath the logic board. Use a black stick to release the connector. 3. Using a T8 screwdriver, remove the two self-tapping screws on the...

Part Location

Disconnect the ten cables from the connectors on the logic board. Note The speakers would already be removed. 2. Using a T10 torx screwdriver, remove the screws from the logic board. Note the locations of the three self-tapping screws marked by and S in the photo . The rest of the screws are machine screws. Rotate the unit so the power supply is in the bottom right corner and the optical drive is on your left. With a black stick, disconnect the power supply cable on the underside of the...

Replacing the LVDS Cable

Position the LVDS cable on the back of the display panel as shown. 2. Connect the LVDS cable connector. When connected correctly the locking levers will secure the connector and it cannot be disconnected without depressing the levers. 3. Secure the LVDS cable to the panel with one strip of tape. 4. Replace the display panel. Note If you are replacing the display, a piece of black mylar is enclosed in the box with the display module. The dotted lines below show the correct placement of the...

Removing the Optical Drive

Macbook Optical Temperature Sensor

Disconnect the sensor cable from the temperature sensor on top of the optical drive and remove the two T10 screws from the optical drive clip on the logic board. 2. Note Make sure to use a needlenose pliers with teeth to remove the optical drive. The pliers must have a textured surface to properly grasp the optical drive release tabs. 3. Locate the black tabs at each side of the plastic optical drive mounting bracket. Starting at the release tab that is furthest from the logic board, grasp...

No Video

No Video, No Boot Chime, White LED ON Symptom 1 The iMac will turn on indicated by the front LED ON , but there is NO boot chime and No Video on the display. The faint sound of the fans, hard drive, and optical drive may also be heard. 1. Follow instructions in the General Information chapter to reset the SMC. Does the computer display video after successfully resetting the SMC 2. Verify that only supported SDRAM memory has been installed and that it has been installed correctly. Unsupported...

Remove the Hard Drive

Imac Bad Display Data Cable

Position yourself at the base of the computer closest to the stand. 2. Pull in on the edge of the mounting bracket until you feel it release from the chassis. Pull HARD The hard drive bracket will release on the end near your hands. 3. Disconnect the hard drive power and data cables. Set the hard drive aside. 4. Note If you are replacing a bad hard drive, remove the mounting bracket and the mounting pins shown in the following steps before returning the bad drive to Apple. 5. Using a T10...

Remove the LVDS Cable

Locate the LVDS cable on the back side of the display panel. Remove the piece of tape circled that secure the cable to the panel. To access the connector, peel back the black mylar tape that partially covers the LVDS connector. 1. Locate the LVDS cable on the back side of the display panel. Remove the piece of tape circled that secure the cable to the panel. To access the connector, peel back the black mylar tape that partially covers the LVDS connector. 2. Remove the tape securing the LVDS...

Diagnostic LEDs

Diagnostic Leds Imac

The iMac has three built-in diagnostic LEDs and a front LED on the main logic board shown below that can help you to troubleshoot the computer. 1. Follow the take apart instructions to remove the RAM access door, front bezel, and lower EMI shield. 2. Locate the SO-DIMM slot and LVDS video connector. The three troubleshooting LEDs 1, 2, and 3 are located to the right of the LVDS cable connector, under a square of black tape. Peel back the tape to view the LEDs. Note that the LEDs are marked 1,...

Audible buzzing whining or ticking noise

The iMac contains several mechanical devices such as motors and fans that may make audible buzzing, ticking, or whining noises when they are operating in a normal manner. The sounds will vary depending on how the system is used. When troubleshooting abnormal noises try the following 1. Verify that the computer is running a supported version of the Mac OS X operating system. If an earlier version of the operating system has been installed then the fans may run at excessive speeds. 2. Determine...

How to Reset the System Management Controller SMC

The System Management Controller SMC is a chip on the logic board that controls all power functions for your computer. If your computer is experiencing any power issue, resetting the SMC may resolve it. The SMC controls several functions, including Telling the computer when to turn on, turn off, sleep, wake, idle, and so forth. Handling system resets from various commands. Note that resetting the SMC does not reset the PRAM. Resetting the SMC will not resolve issues in which your computer is...

Power On Self Test POST

Intel-based Mac computers rely on a combination of tones and blinking LEDs to display Power If the computer detects out-of-specification or no SDRAM or the RAM installed does not meet the appropriate specifications, the screen will remain black but the power LED on the front of the computer will blink once per second to signal the error. This error condition may be due to physically damaged RAM, installing the incorrect type of RAM, or not having RAM installed. Some RAM may appear to pass the...

Lower EMI Shield

Emi Shielding Tape Around Lcd

EMI tape covers the top and sides of the display panel, and the lower EMI shield covers the logic board along the bottom of the unit. The EMI tape and lower EMI shield are easily damaged when removed, and removal is necessary in order to access most components within the unit. Should the EMI tape that seals the display, or the EMI shield covering the bottom of the enclosure see photo below accidentally tear, use EMI tape 922-4786 or 922-5026 to repair and completely seal the unit. When properly...