USB Problems

USB problems refer to symptoms or issues that may occur with external USB devices that are attached to the iMac. This could include Apple and or third-party USB devices. Not enough power for the USB device to function. The following error message will appear confirming that a device cannot function at all due to a lack of power. This lack of power (depending on the device) can be a result of a disconnected external power source, or not enough power available from the hub the device is connected...

Testing for Power

The iMac requires trickle voltage (+5 TRKL) in order to poweron. If you are experiencing power problems in the iMac unit, you will want to test for trickle power to pinpoint the location of the problem and to determine whether or not the power supply analog board is functioning normally. If you have trickle power in the system, the odds are your power analog board is OK. In general, you should test for power at the AC outlet first. Next, it is best to check the logic board. In this way, you...

Power AnalogVideo Board

Before you begin, discharge the CRT, rest the computer on an ESD mat or other soft surface and remove the following Note There are two power analog video boards, part number 661-2465 (with a switch at SW901) and 661-2466. Exchange like-for-like. Warning This product contains high voltage and a high-vacuum picture tube. To prevent serious injury, discharge the CRT. 1. Disconnect the microphone connector located near the top of the CRT. 2. Unwrap the bendable cable wraps in the upper left and...

HFS Plus Formatted Drives

The hard drive in the iMac is formatted with HFS Plus (also referred to as Mac OS Extended format). It is important to note that Norton Utilities version 3.5 is not compatible with HFS Plus (or Mac OS Extended format), and in fact, can destroy data on the hard drive. Norton Utilities version 3.5.3 or 3.5.2 will not attempt to repair a drive formatted with Mac OS Extended format and versions 3.5.1 and earlier cannot recognize that a hard drive is in Mac OS Extended format and can result in hard...

PowerOn Self Test

There is a power-on self test that resides in the ROM of the iMac. This test automatically runs whenever the iMac is powered on after being fully shut down (the power-on self test does not run if the machine is only restarted). If a problem is detected during the test, you will not hear a normal startup chime. Instead, the system will beep as explained below. Refer to Error Beeps later in this chapter for instructions on how to troubleshoot and repair an iMac that sounds error beeps at startup...

Flashing Question Mark

This problem refers to a flashing question mark that appears on the screen during startup. Corrupted system software or software drivers. Boot from the system CD that came with the unit. Can you see the hard drive on the desktop Yes The system software is most likely the problem. Reinstall system software. (You must use the system software CD that came with the unit to get the correct version of Mac OS with the appropriate iMac enablers.) No The hard drive or its software drivers are most...

IMac Summer

Imac Exploded

Note The parenthetical product description Summer 2001 refers to the summer of the Northern Hemisphere. Screw CapTop Left 922-4142 Microphone 922-4277 see Colored Service Parts Exploded View see Colored Service Parts Exploded View see Colored Service Parts Exploded View see Colored Service Parts Exploded View see Colored Service Parts Exploded View see Colored Service Parts Exploded View LED Power Board, w White LED 922-4524 CD-ROM, 24x 661-2346 CD-RW, 6X 661-2424 DVD-ROM, 6x, 661-2342 CTO only...

The PMU Chip

Resetting The Pmu Chip Procedure

The PMU Power Management Unit is a microcontroller chip that controls all power functions for the computer. The PMU is a computer within a computer. It has memory, software, firmware, I O, two crystals, and a CPU. Its function is to Tell the computer to turn on, turn off, sleep, wake, idle, etc. Manage system resets from various commands. Maintain parameter RAM PRAM . Manage the real-time clock. Important Be very careful when handling the main logic board. Remove the battery when handling the...

Distorted Video

Distorted Video refers to a problem with the screen geometry or focus. Adjust the focus using the Display Adjustment Utility on the MacTest Pro CD. See Focus in the iMac Adjustments chapter for instructions. Screen geometry is out of adjustment display is off center, sides or top of the screen are not straight, etc. . Adjust the screen geometry using the Display Adjustment Utility on the MacTest Pro CD. See Geometry in the iMac Adjustments chapter for instructions. Screen cutoff or white...

Jumper Adjustment Tool

The jumper adjustment tool 922-4165 must be installed to save cutoff and white balance adjustments to the factory space. Warning This product contains high voltage and a high-vacuum picture tube. To prevent serious injury, review the Safety information online at http service.info.apple.com. Select Troubleshoot and Repair, and click on Safety under the Tools list. 1. Remove the bottom housing and the top rear housing to access the video board. 2. With the power off, remove the left ground cable...

CDROM or Dvdrom Wont Eject

How Force Eject Imac

CD-ROM or DVD-ROM disc won't eject from the slot. 1 Press and hold down the mouse button on startup. Note This only works on iMac computers with Boot ROM version 2.3 or higher. To check the Boot ROM version, open Apple System Profiler System Profile tab Production information Boot ROM Version. 2 Try manually ejecting the disc. Push a paper clip through the manual eject hole located on the right side of the CD DVD slot. Refer to Ejecting a CD or DVD Disc, Part 1 earlier in this chapter. 3...

Modem Not Recognized

This table should help you troubleshoot and fix problems when the internal modem is not recognized. Follow the instructions under the Possible Fix column to resolve the problem. Modem Is Not Recognized If the modem is not recognized or listed in the application or OS, refer to this section of the table. Needed extensions or CCL files are not installed or are corrupt. Are the correct CCL and extension files installed Note You will need the iMac Modem Extension and the iMac internal modem CCL....

Light Meter Setup

Screen Luminance

This topic covers setup for light meter Model R77, service part number 076-0310. Note The adjustments were optimized for light meter Model R77. To obtain more consistent color results, use only the R77 light meter when performing color adjustments on the slot-load Mac. Before you begin, remove the 10X multiplier plate from the lens. Three scales are shown on the light meter Because display screen luminance typically ranges from 10 to 50 fc, take readings from the bottom scale only. To measure a...

Modem Performance Issues

This table should help you troubleshoot issues with the speed or response time of the modem. The table is divided into different sections, each with its own symptom and cure s . Find your symptom and then follow the instructions under the Possible Fix column to resolve the problem. This table should help you troubleshoot issues with the speed or response time of the modem. The table is divided into different sections, each with its own symptom and cure s . Find your symptom and then follow the...

USB Printer Problems

This troubleshooting table deals with an iMac that cannot print to an attached, known-good USB printer. Printer is not compatible with the iMac USB bus. Verify with the manufacturer of the printer that it is iMac compatible. Open the Chooser and verify that you have the correct printer and printer driver selected. Bad printer driver or hardware problem. Use Apple System Profiler to see if it recognizes that a USB printer is connected. Yes Reinstall the printer driver. No The printer or its...

Hard Drive Problems

Hard drive problems include a hard drive that doesn't operate it doesn't spin or a hard drive that doesn't mount it doesn't appear on the desktop . Can you see the hard drive using Drive Setup Yes Use Drive Setup to reinstall the software drivers for the hard drive. If the problem persists, use Drive Setup to reinitialize the hard drive. See Kbase TIL article 22206 for instructions. Warning You will lose all data on the hard drive when you reinitialize it. Backup the data first if possible. Bad...

Sound In Problems

Sound in problems involve the internal microphone. Symptoms could be audio recording quality is poor, a high level of background noise is noticeable, or no sound is recorded. Open the Simple Sound Control Panel found under the Apple Menu . Select CD Quality under the Sound menu to minimize noise on the internal microphone. Did this solve the problem Yes If the initial sound in problem was with the sound control panel the problem is solved. No Go to next step.

Ejecting a CD or DVD Disc Part

The CD DVD eject mechanism is electrical rather than mechanical on the iMac. If you wish to eject a bootable CD-ROM disc at startup, simply hold down the mouse button until it ejects. If the CD is not a bootable disc, simply wait for the iMac to boot and drag the CD icon to the trash can. If this fails to release the CD, there is an eject button which can be activated by a small, blunt object such as a paper clip. The button is located on the right side of the CD slot. Note that the power must...

Procedure

Macintosh Classic Crt

Check for bent pins on the CRT neck see Figure 1 . Remove the video board and observe the pins on the CRT neck. Make sure all of them are straight. If the pins are not straight, carefully attempt to straighten them with a flatblade jeweler's screwdriver or needlenose pliers and test the board again. 2. Make sure the video board is properly seated on the CRT neck see Figure 2 . The top picture shows the video board improperly seated the bottom picture shows it properly seated. When the video...

At the Logic Board

Xserve Psu Tester

With the iMac placed with the CRT face down on a soft surface, remove the bottom housing and the EMI cover to access the logic board. Testing J9 for 5 V Trickle Power on the Logic Board You will need a volt meter to test for power on the logic board. Refer to the picture on the next page to locate the necessary test point referenced in the following procedure. Plug in the computer, but leave the iMac powered OFF. Ground the black probe on the volt meter to the logic board screw, as shown in the...

Cursor Problems

This section deals with a cursor that moves on the screen, but clicking the mouse has no effect or double-clicking the mouse does not open an application, disk or server. Reset parameter RAM. Hold down lt Command gt lt Option gt lt P gt lt R gt during startup but before Welcome to Macintosh appears. Boot off the system CD that came with the unit. Does the cursor work now Yes Reinstall system software. You must use the system software CD that came with the unit to get the correct version of Mac...

Sound Out Problems

Sound out problems refer to a lack of sound coming from the internal speakers located on the front of the unit directly below the display , external speakers connected via the I O panel to the speaker connector on the logic board , or both. First, disconnect any external microphones, speakers or headphones. Next, verify that volume setting in Control Panel is adequate and that mute is not checked. Test the for sound coming from the internal speakers. Do you have sound now Yes If the initial...

Intermittent Shut Down or Sleep

An iMac with a sticking power button can generate unpredictable behavior. The iMac randomly shuts itself off or puts itself to sleep. The iMac will not start up from either the front power button or the keyboard. Improperly aligned front power-on button -If the front power-on LED is not centered properly within the inner button hole, the power button can become stuck between the LED and the inner bezel resulting in a no power, intermittent shut down, or sleep situation. Refer the LED Alignment...