STA-2100 AM/FM Stereo Receiver (310-2076) Hints and Tips Faxback Doc. # 33511 There is a power on protection relay that protects the power switch and fuse from potentially damaging in-rush current. In addition, the high power amplifier output stages are kept off for a few seconds while the power is turned on. (During this period the pilot LED will glow red.) When the power supply circuitry and audio preamp stages have stabilized, another relay switches in the high power amp stages (and the LED indicator turns green). (IR-06/21/96)