IBM 6565 - PC 300 PL, User Manual

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Device troubleshooting charts
You can use the troubleshooting charts in this section to find solutions to
problems that have definite symptoms.
Important
If you find it necessary to remove the computer cover, first read “Safety
information” on page ix and “Removing the cover — desktop model”
on page 64 or “Removing the cover — tower model” on page 68 for
important safety information and instructions.
Beep code Probable cause
1–1–3 CMOS write/read failure
1–1–4 BIOS ROM checksum failure
1–2–1 Programmable interval timer test failure
1–2–2 DMA initialization failure
1–2–3 DMA page register write/read test failure
1–2–4 RAM refresh verification failure
1–3–1 First 64 KB RAM test failure
1–3–2 First 64 KB RAM parity test failure
2–1–1 Secondary DMA register test in progress or failure
2–1–2 Primary DMA register test in progress or failure
2–1–3 Primary interrupt mask register test failure
2–1–4 Secondary interrupt mask register test failure
2–2–2 Keyboard controller test failure
2–3–2 Screen memory test in progress or failure
2–3–3 Screen retrace tests in progress or failure
3–1–1 Timer tick interrupt failure
3–1–2 Interval timer channel 2 test failure
3–1–4 Time-of-day clock test failure
3–2–4 Comparing CMOS memzize against actual
3–3–1 Memory size mismatch occurred
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PC 300PL and PC 300GL User Guide