IBM 704 - Manual (Page 262)

Beep Codes
Beep Codes
One beep and the appearance of text on the monitor indicate
successful completion of POST. When POST detects a fatal error,
the tests stop, and the server emits one or more beeps. Beep codes
are sounded in a series of individual beeps. The duration of each
beep is constant.
Beep Code Chart for Server Startup
Beep Code Description
1 Refresh failure
Action: Have the system serviced.
2 Parity can't be reset
Action: Have the system serviced.
3 First 64k memory failure
Action: If you have just installed or removed memory modules or
the memory board, make sure that all memory modules and
the memory board are seated properly. If the problem recurs,
have the system serviced.
4 Timer not operational
Action: Have the system serviced.
5 Processor failure
Action: Have the system serviced.
6 8042 gate a20 is off (v_mode)
Action: Have the system serviced.
7 Exception interrupt error
Action: Have the system serviced.
8 Display memory read/write error
Action: Have the system serviced.
9 ROM checksum error
Action: Have the system serviced.
10 Shutdown reg. read/write error
Action: Have the system serviced.
244 PC Server 704 User's Handbook