Washer is behaving erratically. Sometimes it completes all cycles. But most of the time it seems to fail between the Rinse and the final highspeed spinnout. I read over the diagnostic guide and tried to run it through the diagnostic steps. I attempted the steps to initiate the manual diagnostic steps, i.e. hold in and then release a key for 4 seconds, repeating this four times. However this initiated the "automated test procedure". It completed the following tests:
C:00 tested the door locks OK
C:01 tested that tub fills with water OK
C:02 tested the soap dispenser mechanism OK
C:03 tested if tub filled with hot water OK
C:04 tested that drum rotated clockwise at wash speed OK
C:05 skipped this test since this model apparently does not have a heater
C:06 tested that drain pump drained out the water OK
C:07 test if drum rotates counterclockwise at 35 to 90 rpm

This is where the test fails. The drum tries to start in that direction but then everysthing stops, and their is nothing displayed on the screen.
On reinitializing the test, sometime I get an F71 code before the I complete the press in and release a key for four seconds four times.
Next, with nothing in the washer we turned it on normally and set it for an "Express Wash". It completed everything perfectly even the high speed final spin out.
However today when we tried an actual load in it, we pressed power and it came on, we selected the cycle we wanted, but then when we pressed START it would not start the cycle.
From the code interpretation table, the F71 code which we sometimes saw during the diagnostic tests has sometime to do with a "heartbeat failure" due to a lack of communication between the user interface boards and computer control unit. In the Appliance Parts list for this model, there seem to be two boards depicted for PN AP4539789 which must come as a set, but at a very high price of around $300. Do you think I might have a loose connection on one of those boards, since the washer sometimes performs flawlessly...or do you think there is some component on one of those board that is misfunctioning intermittently? I haven't taken them out to inspect them yet.
Many thanks for any suggestions anyone might have!!!