apple iMac Repair Manual free download

File name iMac_Repair_Manual.pdf

K Service Source iMac K Service Source Hot Issues iMac Hot Issues Introduction - 1 Introduction This chapter is designed to highlight unique or high- priority product issues that you should be aware of before servicing the iMac computer. This chapter alerts you to important issues and provides pointers to other areas in the manual where more complete information can be found. This chapter is not intended to replace other parts of this manual; it merely provides a pointer to pertinent information in those chapters. To familiarize yourself with a new product family, always read the Basics chapter in its entirety. You should also refer to the Troubleshooting chapter for basic theory of operations information. Hot Issues Introduction - 2 Mixed Memory Types The iMac computer uses SDRAM SO-DIMMs only; EDO memory will not work in the iMac computer. System problems will result if EDO memory is installed. (See "SDRAM DIMMs" in the Basics chapter and refer to the iMac section of the Memory Guide.) Note: Customers are allowed to upgrade the memory in iMac computers and may inadvertently mix EDO and SDRAM memory. If incompatible memory types are installed, you will hear two beeps upon startup. (See "Power-On Self Test" in Troubleshooting for more information.) Hot Issues SGRAM Video Memory - 3 SGRAM Video Memory The iMac computers use SGRAM video memory. Use only SGRAM SO-DIMMs in these machines. Never install the 256K or 512K video memory DIMMs used in older Macintosh computers. (See "SGRAM Video Memory" in the Basics chapter.) Error Beeps If problems are detected upon startup, the iMac system will sound one or more error beeps. (See "Error Beeps" in the Troubleshooting chapter.) Hot Issues HFS+ Formatted Drives - 4 HFS+ Formatted Drives The iMac hard drive is formatted from the factory with Mac OS Extended format, also referred to as HFS+. Norton Utilities version 3.5 is not compatible with HFS+ and version 3.5.1 and earlier can result in hard drive corruption and loss of all data on the hard drive. (See "HFS+ Formatted Drives" in the Troubleshooting chapter.) Hot Issues Universal Serial Bus - 5 Universal Serial Bus The iMac uses a Universal Serial Bus (USB) for co