[Muerte]

I was having a problem with the oven shutting off when it was hot. Some times it would reach the desired temperature, some times it would shut off after barely getting warm. A sharp whack with my fist above the display would sometimes turn it back on, but not always, and it would shut off shortly afterward. I tested the oven temp limit switch and fan switch - neither were the cause.
I was about to send the control board to a repair shop ($200 !) but decided to give it another look. While disassembling it I found that wiggling the main power connector (beneath the transformer) on the control board would cause the display to flicker. Upon inspection I found the solder joints on the main connector to be cracked. This explains why it seemed so random and why hitting it would sometimes fix it. Re-soldering the joints seems to have fixed it. It has worked for several meals now.
So, if you're having the "shuts off" issue - as several people have in the past - first check the two temperature switches as described in other posts. If that doesn't work then inspect the control board thoroughly. Look at the solder joints on the backside of the circuit boards. Old solder can crack in a circle around the pin and give you a bad connection.
Hope this helps.

Marty.
*Disclaimer: I am not a repair tech. I probably got lucky on this one!