Replacing amplifier power switches
After repeated uses the power switch may sometimes wear out, seize, arc, lose its spring tension, fail to make a connection, or otherwise go bad. Replace a bad switch with a brand new one (QSC part # SW-000016-SW or SW-000088-GP, orderable for US customers at http://www.qscparts.com/) by following these simple instructions.
Confirm that the power switch is faulty.
- Connect the amplifier to AC mains power. While you listen for the crackling sounds of electrical arcs within the power switch, turn the switch on and off a few times. If the switch seems to arc significantly, unplug the amp from AC mains and proceed to step 3.
- Unplug the amp from AC mains power. Remove the amplifier cover. Detach the wires from the power switch and check for continuity across its terminals while you toggle the switch back and forth. You should measure 0 ohms when the switch is in the “on” position and infinity (open) when it is “off.” If it does not function properly, proceed to step 3.
- If the switch feels flimsy or mechanically compromised for any reason, prepare to replace it. Proceed to step 3.
Replace the switch.
- Detach the two AC wires connected to the switch. Using wire cutters, cut the two retention latches at the top of the switch. Push the switch out of the faceplate and discard it.
- Insert the new power switch into the faceplate. Confirm the correct orientation before inserting the new switch. It should snap into place firmly and sit flush with the surface of the faceplate. Reconnect the AC wires (polarity does not matter) to the switch terminals.
- Reinstall the top cover.
- Plug the amplifier into AC mains power. Test the power switch and make sure the amp turns on and off reliably.