aa said:
When turning on instead of that double beep, the computer starts emitting
single beeps at regular intervals and the monitor remains black.
What might be wrong?
Whether this is a coincedence, but this began when attempting to connect the
computer to a quite old monitor. On another computer that monitor was
working, though only at low resolution.
Many computers generate some sort of sound when first powered up. All
the desktop computers I've used normally generate a SINGLE beep on the
tiny speaker inside the case (NOT the external speakers). Lacking
alternatives the laptops used the equally tiny speaker that the laptop
also used for most Windows sounds. Those beeps are generated by the
computer's ROM based Power On Self Test (POST).
IF the computer is able to use the display it will report any problems
detected during the POST on the display. Hardware failures that prevent
the computer from displaying an error message produce a different POST
beep pattern. The POST error beeps vary depending on which manufacturer
built the computer and cannot be interpreted without obtaining
documentation through the manufacturer. Knowledge of the computer model
number WILL be required to obtain the relevant POST beep code list
(motherboard manufacturer and model number for a local computer shop's
"gray box" custom made towers).
Most operational displays will produce some text based startup messages
within a few seconds of the user pressing the tower's "power" button.
Some models display the computer manufacturer's logo. These power up
messages are dependent on the proper operation of the graphics card or
display interface circuits built into the motherboard and should be
within a vertical refresh frequency range compatible with nearly all
displays. Occasionally a user will set Windows to a vertical refresh
rate too high for the display, normally producing an out of range error
on the display (generated by the display's circuitry). That problem can
normally be corrected by booting Windows in safe mode to permit the user
to see the display settings pop-ups.