IBM 6862 User Guide - Page 142

POST Beep Codes One beep and the appearance of text on the monitor indicate successful completion of POST. More than one beep indicates that POST detected an error. Beep codes are sounded in a series of two or three sets of beeps. The duration of each beep is constant, but the length of the pause between the beeps varies. For example, a 1-2-4 beep code sounds like one beep, a pause, two consecutive beeps, another pause, and four more consecutive beeps. It is possible to misinterpret beep codes if you do not understand exactly how they work. Keeping in mind that POST beep codes vary in the length of the pause, and not the duration of the beep tones, will help you to distinguish the beeps. POST Beep Code Table For the following beep codes, the numbers indicate the sequence and number of beeps. For example, a "2-3-2" error symptom (a burst of two beeps, three beeps, then two beeps) indicates a memory module problem. An x in an error message can represent any number. If the following beep codes occur, have the system serviced. Beep Code 1-1-3 1-1-4 1-2-1 1-2-2 1-2-3 1-2-4 1-3-1 1-3-2 2-1-1 2-1-2 2-1-3 2-1-4 2-2-2 2-3-2 Probable Cause CMOS write/read failure BIOS ROM checksum failure Programmable interval timer test failure DMA initialization failure DMA page register write/read test failure RAM refresh verification failure First 64 K RAM test failure First 64 K RAM parity test failure Secondary DMA register test in progress or failure Primary DMA register test in progress or failure Primary interrupt mask register test failure Secondary interrupt mask register test failure Keyboard controller test failure Screen memory test in progress or failure 124 Using Your Personal Computer