In a message dated 9/6/01 11:13:48 PM Eastern Daylight Time, [log in to unmask] writes: > Hi friends, > > when I switch my monitor on, it starts with a " twung or Dung noise", > little louder than the normal starting indication. > Can somebody please tell me what it is .Is it a signal for a future > trouble ? > Pl advise. > Jagpal S.Tiwana > Dartmouth, NS, Canada Hi, Monitors (and TV's for that matter), have degaussing coils around the picture tube, to remove any stray or residual magnetism in the tube, that can affect the color of the picture. The circuit that operates them typically has a thermistor in series with the coil. The thermistor has a low resistance when cold, and a much higher resistance when warm. So when you first turn on the monitor, the cold thermistor lets a lot of current flow through the degaussing coil, producing the noise you are hearing (and degaussing the screen). The current flow heats the thermistor up, causing its resistance to increase, and effectively shutting off the coil after a few seconds (and it stays off as long as the monitor stays on). Then when the monitor gets turned off, the thermistor cools down, and the cycle repeats the next time the monitor gets turned on. HTH, Peter Hogan [log in to unmask] The NOSPIN Group is now offering Free PC Tech support at our newest website: http://freepctech.com