Kenmore Range 790.31043803 Control Board iffy?

[Capon]

My Kenmore Gas range, 790.31043803 seems to work fine when set at 350°. However, when set at a higher temp like 425°, the oven randomly shuts off. In fact all power is off (the display is black). When I first noticed this, I opened the oven door and let it slam shut . The power would then light up the display to 12:00. I then have to set the clock and then select the temp to continue baking. However lately, the oven door slam doesn't seem to work. I now have to slam my fist onto the top panel (the display) and then power is restored. It's happening too often. Last night when my wife used the oven at 350° it worked fine. no problems. But then she had to put the pan under the broiler. So when she selected the BROIL setting to broil the last few minutes of cooking, the oven shut off (no power). Again, I slammed the display until power came back on (indicated by 12:00 in the display). A thermocouple & igniter was replaced a couple of years ago.
For the past few months I've been trying to determine what's happening, At first I suspected a loose connection on the control board. So I disconnected & reconnected all connectors on the board. I thought it was fixed but the problem still exists. It seems that when the oven gets hot is when the power interruptions occur. I suspect it could be a harness (power supply wire) or a power relay that's sensitive to heat. Any ideas of how I can pinpoint to problem or do you think a new board is inevitable. Can the board be tested and possibly fixed (ie solder joint) ?

 

[Josh Smith]

I would start at the wall and check voltages and connections coming in the the terminal block to the main board. Something is obviously failing under the increased heat. Is there a cooling fan? If so is it working correctly?