Micronics 60/66MHz - Manual (Page 37)

Beep Codes
Beep codes are a series of beeps sent through the speaker which indicate
a problem during POST. If text appears on the video screen, the M5Pi
has completed POST; any other tone from the speaker indicates some-
thing other than a POST error. These tones are not described in Table
B-1.
The beep error codes are a series of three sets of beeps. The duration of
the beep tones are constant, but the length of the pauses between the
beeps varies. For example, a 1-3-3 beep code will sound like one beep,
a pause, three beeps consecutively, another pause, and then three more
beeps.
One beep code is often misunderstood. With no video card installed, or
if the video card is failing, the system board will generate a long-short-
long-short beep code. This is often interpreted as a 1-2-1 beep code.
But POST errors always vary in the length of the pause, and not the
duration of the beep tone.
Another way of identifying a POST error is to use a device called a
POST-card. This peripheral card is inserted into one of the ISA slots
and has an LED (or LCD) read out showing the contents of port 80h.
The following table provides a list of all beep codes and probable
causes.
B
B-1