Mxkc68 pops loudly through the speakers on switch on and reverts to standby?

You have a solid state chip or transistor that is failing.

Hums are generally caused by electrolytic capacitors that have gone. You should replace any large ones in the power supply section of the unit.

Sounds like DC leakage....pre-drive and/or output transistors (or IC) becoming intermittent often pass DC voltages to the speakers. The "pops" you hear are these DC pulses being passed to the speakers and the "cutout" is the protection circuitry doing its job...protecting the speakers. Speakers want AC voltages...plus voltages moving the cone in one direction, and a negative voltage moving it in the opposite direction. DC voltages push the speaker cones in a single direction and hold it there until it fails. The bad news...it's repair shop time.

Sounds like a Electrolytic capacitor has failed. Search backwards from the speaker connections inside the unit to the main PC board. Replace the first ones that you come accross that are linked with the speakers.

First try to find the source of your problem. The easiest way would be to try your sub with a different audio source to see if the problem still occurs but is sounds more like there's a problem with the receiver.

Surface Mount diodes around transformer on right back side of unit. Know issue with 38 and 68s.

http://www.forums.hcsd.com.au/cgi-bin/forum/Blah.pl?m-1301007851/

this **** dont mother ******* work **** ALL YALL HOES how u like that

Hello Fixya customer,

Thank you for your question.

The best way to fully isolate the fault is to disconnect all the speaker wires, and verify that there are no strands of wire shorting between the speaker terminals on the rear of the unit.

Turn the volume all the way down, full CCW, and if it goes into shut down with the STBY light blinking then there is a fault in one of the amplifier's.

Thank you for using Fixya, and if I can be of further assistance please ask.

Switch the wires on the two speakers at the box and see if the problem moves to the other speaker. If the second speaker starts popping and the first one stops, the problem is in your amplifier. If the same speaker keeps popping then you probably have a blown sub.