Apple imac 20 inch early 2008 User Manual
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iMac (20-inch Early 2008) — Symptom Charts 2 51 The computer won’t burn discs Check whether the drive can read CDs and DVDs normally. Perform the steps above for “CDs 1. or DVDs don’t show up on the Desktop.” Try a test burn by creating a Burn Folder, as follows. 2. • In the Finder, choose “New Burn Folder” from the File menu. • Open the Burn Folder, drag an item inside for testing, and click “Burn” in the upper right corner of the window. • When prompted, insert a blank disc and follow the dialog instructions. Does the disc burn successfully (problem solved), fail with an error, or is the disc ejected? If the disc fails to burn with an error, check for these error messages. 3. Unknown Error -2147352480. See Knowledge Base article 25480 and 2575 0 for more information. Buffer underrun error. See Knowledge Base articles 25480 and 25750 for more information. Unknown Error. If the blank disc is ejected, try another blank disc. If the issue persists, try another brand and 4. speed of blank media; if you’re using blank CD media, see if this happens with blank DVD media. If the drive consistently rejects all blank media, or only rejects blank CD media while accepting blank DVD media or vice versa, replace the optical drive flex cable and test. Does the drive successfully burn to disc after replacing the optical drive flex cable? Yes: Problem solved. No: Replace the optical drive. Does it burn correctly now? Yes: Problem solved. No: Replace the logic board.
iMac (20-inch Early 2008) — Symptom Charts 252 Optical drive does not accept CD / DVD disc The optical drive on this computer has narrow tolerances for the recommended optical media. If the drive does not accept discs, the wrong kind of disc could be inserted. Open the computer and slowly lift the panel. Verify that the four inverter-to-panel-cables are 1. not resting on top of the optical drive. The inverter cables should be tucked into the open areas at the top and the bottom of the optical drive. The optical drive is delicate and if the cables are pressing on the top of the optical drive it could impair the functionality of the optical drive. Check for a small (non-standard) disc or other foreign object stuck inside. Remove the optical 2. drive from the system to extract a stuck disc. See Knowledge Base article 86382 - “Macintosh: How to Remove a Stuck Disc From a Slot-Loading Drive.” Reseat the optical drive into the rear housing. After replacing the optical drive, plug in the 3. computer and test the optical drive by inserting and ejecting DVD-R media. Repeat the insert/eject test three times. After reinstalling the optical drive, can you now insert a disc? 4. Yes: Issue resolved. Run diagnostics and return the system to the customer. No: Replace the optical drive flex cable and trying inserting a disc again. After replacing the optical drive flex cable, can you insert a disc now? 5. Yes: Issue resolved. Run diagnostics and return the system to the customer. No: Replace the optical drive.
iMac (20-inch Early 2008) — Symptom Charts 253 Fan Sound Fans running at full speed after the computer turns on The customer may have entered a diagnostic mode that causes the fans to run at full speed.* 1. Restarting the system will not restore normal fan operation. To solve the problem, the user or technician should follow instructions in the “General Information” chapter to reset the SMC. *Note: Customers reporting this symptom should be told to press the power button AFTER the power cord has been fully inserted. Inserting the power cord while pressing the power button will cause the fans to run at full speed. Verify that one of the several temperature sensors is not disconnected. Run AHT and ASD to 2. verify sensor functionality. This problem is most likely to occur after a repair. Be sure to check ALL sensor connections (hard drive sensor, optical sensor, LCD sensor on the back of the panel and it’s connection to the left corner of the logic board, and the sensor on the cpu fan connecting to the bottom left corner of the logic board.) Refer to the 3. Apple Hardware Test Error Code char t for a suggested service action.
iMac (20-inch Early 2008) — Symptom Charts 254 System noisy, fails Apple Hardware Test for temp sensor Check the AHT error code on the 1. Apple Hardware Test error code char t. 2. Make sure the LCD temp sensor cable is connected to the sensor on the back of the LCD panel in the top right corner. Make sure the LCD temp sensor cable is fully inserted into the connector on the bottom left 3. side of the logic board.
iMac (20-inch Early 2008) — Symptom Charts 255 Loud fan noise coming from inside the computer The iMac has a trio of fans that circulate air throughout the system. It also includes temperature sensors, and advanced thermal software that spins the fans fast or slow as needed. As the system usage increases, the fans will adjust their speed using advanced thermal software to meet the cooling needs of the system. Under normal conditions, rotating fans will make a slight hum that varies in relationship with their rotational speed and the amount of air that they are moving. In addition, the normal functioning of the hard drive and optical drive will generate additional whirring and scratching sounds that may be audible. All of these sounds are normal and do not indicate a failure with your computer. To begin troubleshooting a possible fan issue first run Apple Hardware Test and refer to the 1. error codes chart in this chapter. Did running Apple Hardware Test identify the suspected part or module? Yes: Connect or replace the sensor or cable causing the loud fan noise. No : Go on to the next step We need to qualify the sound that you’re experiencing. Does the sound occur only under 2. specific light/heavy usage conditions? Yes: CPU intensive applications such as iTunes, Garage Band, DVD Player, etc., or two or more applications open at once will cause the fans to run at an increased rate making them more noticeable. If the sound only occurs when one or more of these applications is running, this is normal. No: If the sound isn’t affected by CPU intensive application it may be due to other factors. Go on to the next step. Is the sound always present, or does the sound vary? 3. The sound is always present: The normal functioning of the hard drive and optical drive will generate additional whirring and scratching noises that may be audible. Check whether this sound is related to one of the components. Go to step 4. The sound varies: Under normal conditions rotating blowers will make a slight hum that varies in relationship with their rotational speed and the amount of air that they are moving. Let’s see if this is indeed the case. Go to Next Step. Are the fans making a normal humming sound that increases/decreases in relation to 4. processor usage? As the fans increase their speed to cool the system the sound level will increase. Launch the Activity Monitor application included with Mac OS X in the Utilities folder to determine whether the noise corresponds with heavy usage of the CPU. Does fan activity increase / decrease with the CPU Usage graph in Activity Monitor? Check by running CPU intensive applications such as iTunes.
iMac (20-inch Early 2008) — Symptom Charts 256 Yes: This is normal operation and none of the fans require replacement. No: If the fan activity does not coincide with CPU usage, the sound you’re hearing may not be fan activity. Go to the Next Step. The normal functioning of the hard drive and optical drive will generate additional whirring 5. and scratching noises that may be audible. We can isolate these noises by booting the computer to the iMac Install Mac OS X Install Disc 1. - Place the disc in the drive, and restart your machine while holding down the “C” key as the machine starts up. - Once at the Installer window, choose Open Disk Utility from the Installer Menu. - Once Disk Utility is open, select the system’s hard drive and on the toolbar choose Unmount. Note: if the drive has multiple partitions, unmount each of these partitions. This will spin down the hard drive. The optical drive will also be busy at this time; wait a moment for the optical drive to spin down also and then listen to the machine. Is the sound still present? Yes: With the hard drive and optical drive inactive, all you should be hearing are the fans in the machine. While booted to the CD, these fans should be running at a lower level since CPU activity is low with both drives inactive. Fan sound that includes objectionable ticking, whistling, or squealing may require further investigation and/or replacement of the particular fan. Go on to the next step. No: The normal functioning of the hard drive and optical drive will generate additional whirring and scratching sounds that may be audible. All of these sounds are normal and do not indicate a failure with the machine. ” Shut down the computer, remove the power cord and any other connected cables, and 6. remove the access door and front bezel. Stand up the computer, plug it in, and start it up by pressing the external power button. As the machine starts up, listen carefully to each of the three fans, and see if you can locate the fan from which the objectionable ticking, whistling, or squealing sound is coming. The CPU fan is the left-most fan, the hard drive fan is in the center, and the optical drive fan is on the right. Can you pinpoint the fan making the sound? Yes: Replace the noisy fan. No: If you can hear an objectionable ticking, whistling, or squealing sound, but you cannot identify the source of the sound, contact Apple Technical Support.
iMac (20-inch Early 2008) — Symptom Charts 257 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: Verify that the computer is running a supported version of the Mac OS X operating system. 1. If an earlier version of the operating system has been installed then the fans may run at excessive speeds. Run Apple Hardware Test (AHT ). Check any failure codes against the 2. error codes chart in this chapter. Determine that this noise is related to the computer by removing and shutting down all 3. other devices in the vicinity of the computer that could be causing a sound. Eject any media inserted into the optical drive. The optical drive will make a variety of normal 4. sounds when accessing the optical media. Quit all applications and test the computer again. Processor intensive applications may cause 5. the fans to run at a higher RPM and therefore be more audible. Boot to the latest version of Apple Service Diagnostic for this iMac and select the EFI test 6. suite by holding down the D key during startup. The diagnostic tests fan speeds and thermal sensor functionality. Should tests fail, replace any parts indicated by the diagnostic. Reboot the computer and check the computer again. If the noise persists and is unusually 7. loud, contact Apple Technical Support.
iMac (20-inch Early 2008) — Symptom Charts 258 AirPort Not able to connect wirelessly with AirPort 1. From the Apple menu, choose About this Mac. 2- Click on More Info. System Profiler should open. 3- In System Profiler, in the column on the left, look under Network for a line called “AirPort Card”. Select that line. 4- Does the section to the right say “No Information Found”? Yes: The computer doesn’t realize it has an AirPort card installed. Go to step. 5 No: The iMac recognizes that it has an AirPort card installed. Go to step 6. 5- Remove the access door, front bezel, right speaker, and two card mounting screws, and reseat the AirPort card. Re-install the two card mounting screws and check System Profiler again to see if the computer sees the AirPort card. Does it recognize the card now? Ye s : Problem solved. Replace the front bezel and re-test the system to verify that the original symptom is resolved. No : Replace the AirPort card. Refer to the Take Apart section for AirPort Card. If the issue persists after replacing the AirPort card, replace the logic board. 6- Now that we know the iMac recognizes the AirPort card, check the antenna cables. If the antennas are not plugged in all the way, you may have a very short AirPort range. 7- Remove the access door, front bezel, right speaker, and two card mounting screws. Disconnect the card, and reconnect the antenna cable connectors to the card. Make sure the antenna connectors are firmly seated. Replace the card and other components and retest. 8- If the antennas are plugged in properly and the AirPort card is recognized but the problem persists, there are a number of other things that could cause issues with wireless networking. Refer to Knowledge Base document 10685 8 for more networking information. 9- Replace the AirPort card. 10- Replace the logic board.
iMac (20-inch Early 2008) — Symptom Charts 259 Bluetooth (also see Wireless Issues topic) Bluetooth devices won’t sync with my computer 1. Make sure the computer has a Bluetooth board installed. Open System Preferences (from the Apple menu, choose System Preferences) and verify that “Bluetooth” appears in the Hardware section of the window. 2. Locate the Bluetooth board inside the computer. Reseat the Bluetooth board, Bluetooth cable, and the Bluetooth antenna. 3 Turn on Bluetooth. In System Preferences, click Bluetooth and then click the Settings tab. If you don’t see “Bluetooth Power: On,” click the “Turn Bluetooth On” button. Make sure that you also enable Bluetooth on your device too (please refer to your device’s documentation for instructions). 4 Set up a new device. To set up a Bluetooth phone or PDA, click the Devices tab in Bluetooth preferences and then click “Set Up New Device” to open the Bluetooth Setup Assistant. Follow the onscreen instructions to set up your device. To set up an Apple Wireless Keyboard and Mouse, open System Preferences, click Keyboard & Mouse, click the Bluetooth tab, and then click “Set Up New Device” to open the Bluetooth Setup Assistant. Follow the onscreen instructions to set up your keyboard and mouse. 5 Recharge or replace your Bluetooth device’s battery. If your Bluetooth device’s battery is low, you may experience connection issues. 6 Download and install the latest software for the device. 7 Check for a Bluetooth update. Choose Software Update from the Apple menu (make sure that your computer is connected to the Internet). If newer Apple Bluetooth software exists, Software Update will find it. 8 Check for signal spoilers. Avoid situations in which metal objects come between your device and computer. Don’t put the computer under a metal desk or locked away behind a metal cabinet. Keep cordless phone base stations, microwave ovens, and other electrical devices that operate on a 2.4 GHz bandwidth away. And make sure that the device and computer aren’t more than 30 feet apart from each other. 9 Restart your computer. You may also want to try resetting your computer’s PRAM and NVRAM. 10 Reset your Bluetooth device. First try turning your device off and then on again. If that doesn’t work, see if you can reset your device. 11. Replace the Bluetooth board and test the computer again. 12. Refer to the Bluetooth Support site at http://www.apple.com/support/bluetooth/. 13 Replace the logic board.
iMac (20-inch Early 2008) — Symptom Charts 260 IR Remote Remote won’t communicate with system applications such as iTunes or iPhoto, or with the optical drive Make sure of the following when using the Apple Remote: You are within 30 feet of the front of the computer. • You have an unobstructed line-of-sight to the front of the computer.• You are pointing the lens end of the Apple Remote directly at the front of the computer.• The computer is powered on and awake.• The “Disable remote control infrared receiver” checkbox in the Security pane of System • Preferences is NOT checked. Make sure the active application works with Apple Remote. Apple Remote uses Front Row, • and from Front Row it can access DVD Player, iPhoto, iTunes, and QuickTime Player. Make sure the remote is paired with the computer. Access the System Preferences/Security • pane and check “Unpair” if available. Close the Security pane, and re-pair the Apple Remote with the computer. See Knowledge Base article 302545. Use a digital camera to test your Apple Remote. 1. If you have a digital camera or DV camera with an LCD display, you can use it to see if your Apple Remote is emitting a signal. Infrared beams are invisible to the human eye, but most digital cameras and video cameras use Charged-Coupled Device (CCD) chips or image sensors that are sensitive to infrared light. To use a camera to test your Apple Remote, follow these steps: • Turn on your digital camera or DV camera and remove any lens cover. • Point your Apple Remote toward the camera lens. • Press and hold the Menu button on the remote while looking at your camera’s LCD display. Note: you can also use the iMac’s built-in camera to verify the remote using the PhotoBooth application, however if the IR sensor and remote are not functioning correctly, then pushing the buttons on the remote may activate the FrontRow features during the testing. • If you see a faint blinking light coming from the Apple Remote in the camera’s LCD, then the remote is working properly. • If you don’t see any blinking light in the camera’s LCD, replace the battery in your Apple Remote and then test it again with your computer (see “iMac G5 (iSight): How to replace the Apple Remote battery” for instructions). (KBase article 302543) Does the IR remote now communicate with an 2. active application that works with Apple Remote? Yes: IR remote is functioning correctly. No: Replace Apple Remote.