IBM Desktop Beep code
No beep:::::::::::::::::::::::::::::::::::::::::::::::::::::::::: No power, loose expansion card (ISA, PCI, or AGP), a short, or an improperly grounded motherboard
1 short:::::::::::::::::::::::::::::::::::::::::::::::::: System OK
1 long:::::::::::::::::::::::::::::::::::::::::::::::::::::::: Video/display problem; video card incorrectly seated or defective
2 short::::::::::::::::::::::::::::::::::::::::::::::::::::::: POST Error displayed on monitor
3 long:::::::::::::::::::::::::::::::::::::::::::::::::::::::::::: Problem with 3270 keyboard card
1 long, 1 short:::::::::::::::::::::::::::::::::::::::::::::::::::::::Problem with system board
1 long, 2 short:::::::::::::::::::::::::::: ::::::::::::::::Problem with display adapter (MDA, CGA)
1 long, 3 short:::::::::::::::::::::::::::::::::::::::::::::::::::::::Problem with EGA
Repeating short beeps:::::::::::::::::::::::::::::::::::::::::::Problem with power supply or system board
Continuous beep:::::::::::::::::::::::::::::::::::::::::::::::::::Problem with power supply or system board

IBM Thinkpad beeps code laptop
Continuous beeping::::::::::::::::::::::::::::::::::::::::::::::: System board failure
1 beep with blank display:::::::::::::::::::::::::::::::::::::::::::: LCD connector problem, LCD backlight inverter failure, video adapter failure, or LCD assembly failure
1 beep w/message "Unable to access boot source":::::::::::: Boot device failure or bad system board
1 long, 2 short:::::::::::::::::::::::::::::::::::::::::::::::::::::::::::: System board, video adapter, or LCD assembly failure
1 long, 4 short:::::::::::::::::::::::::::::::::::::::::::::::::::::::::: Low battery voltage
1 beep every second::::::::::::::::::::::::::::::::::::::::::::: Low battery voltage
2 short w/message:::::::::::::::::::::::::::::::::::::::::::::::::: Read the error message on the display
2 short with blank display:::::::::::::::::::::::::::::::::::::::: System board failure