Receiver going in protect mode

My son bought a harmon kardon receiver, apex dvd, and bose 201's. after one week the receiver bit it! (no display, no functions - did not have a protect mode feature). We returned it and purchased an onkyo of better quality. within the first week, it went into protect mode twice and the third time it permanently remained in protect mode. We returned this receiver, including the apex dvd and purchased a sony receiver, sony dvd, and new sony tv. This receiver worked great for one month and now it goes into protect mode at least once every other day, but is revivable by unplugging it from power and unplugging all cabling. We have decent quality monster cable for all audio and video connections. all devices are plugged into a surge protector, and line power is at 120 vac constant. The speaker wiring is in correct polarity, there are no shorts anywhere. The speakers are the only common device that has been connected throughout this ordeal. Does anyone have any ideas what could be the problem? All of the components including the tv and a desk top computer are located on a 10 foot countertop. (maybe theres some kind of cancer causing electro magnetic force field swirling around the components located next to each other) Last statement is meant to be funny or maybe not!!