On a NGC Tornado, oven would warm up fine, when cooking cycle is started, screen will either right away, or within 15 seconds, go blank and oven will continue to operate. Screen remains blank until oven is disconnected from power and then turned back on, then the screen is working fine and oven would operate as normal again, until cooking was started, and again it will go blank. I guessed I/O board but was wrong, new I/O board and right away oven is having same problem.
Anybody seen this? No mention of anything like this is in the service manual