IBM 689912U Hardware Maintenance Manual - Page 213

Diagnostics and Test Information The following tools are available to help identify and resolve hardware-related problems: Power-on self-test (POST) POST Beep Codes Error Code Format Diagnostic Test Programs - IBM PC Enhanced Diagnostics (For all Types, except 6571, 6581, 6573, 6583, 6875, 6885) - PC 300/700 Series, IntelliStation Diagnostics (Only for Types 6571, 6581, 6573, 6583, 6875, 6885) Power-On Self-Test (POST) Each time you power-on the system, it performs a series of tests that check the operation of the system and some options. This series of tests is called the power-on self-test, or POST. POST does the following: Checks some basic system-board operations Checks the memory operation Starts the video operation Verifies that the diskette drive is working Verifies that the hard disk drive is working If the POST finishes without detecting any problems, a single beep sounds and the first screen of your operating system or application program appears. Note Type 6275, 6285, 6561, 6591, 6862, 6889, 6892, 6893 computers are default to come up quiet (No beep and no memory count and checkpoint code display) when no errors are detected by POST. To enable Beep and memory count and checkpoint code display when a successful POST occurs: 1. Enable Power on Status in setup. See "Setup Utility Program" on page 220. If the POST detects a problem, an error message appears on your screen. A single problem can cause several error messages to appear. When you correct the cause of the first error message, the other error messages probably will not appear on the screen the next time you turn on the system. POST Beep Codes The Power On Self-Test generates a beeping sound to indicate successful completion of POST or to indicate that the tests detect an error. Reference Information 203