My model # is WFW9200SQ01. I have intermittent error codes of f70 or f71. I have unplugged and plugged the AC, with some success. A Technician once told me to: "hold the cycle button for 5-10 seconds. Then press the power button and the washer should turn off and the code disappears. Then press the power button again and the washer turns back on without the error code." It worked this time but after about 3 min with the washer on and NO activity at all, I heard 3 beeps and the error came back. I also noticed during the 3 min that the door lite never came on and the door lock never engaged.
... Any help?

You have a communication problem between the control panel where you press the buttons and the computer module (CCU). The most likely cause is corrosion in the wiring harness or the plug on the circuit board. This must be a manufacturing error because it's so common. I would avoid that kind of machine like the plague and only buy top-loading machines. Whirlpool and Maytag are good brands. Sometimes the wiring ribbon rubs against the side of the machine and vibration rubs a hole in the wires or breaks them. Unplug the wiring harnesses and clean the pins well with a fine wire brush that's soft enough to get inside and clean up any corrosion, then spray clean with a good contact cleaner. Clean off the circuit board, too, and look for any dirt or corrosion. It only takes a speck to cause a problem with these front-loading machines. I hate them because they also eat CCU's and MCU's, which you may have to replace.

Just a comment.
Our basic appliances have become too technologically advanced for their actual use. Servicing is becoming both a servicers and consumers nightmare because of the high costs involved. More gadgets only mean more things to go wrong.