I have an all gas Thermador range PDG366ZS. When I try to ignite the oven, I'll turn it on and turn the dial to the desired temperature. The oven emits a short "BZZT" but won't ignite. The oven will not ignite unless I do the following:
1. Set oven to "Broil". Turn dial to "Broil". Light the broiler with a match because the igniter won't spark.
2. Heat up the oven with the broiler for approximately 15 minutes. It gets approximately 350 degrees
3. Turn everything off.
4. Switch knob to "Conv Bake"
5. Turn the temperature dial SLOWLY until the oven light goes out (just before that approximate 350 degree spot on the oven thermometer).
6. The oven gives a longer "BZZZZT" and ignites. It may cut out after getting up to temperature so it needs to be watched. However, once it gets hot, it works fine. However, the oven temp seems to vary and is generally close to what the thermometer says but it is not exact according to my wife, the baker.

I gambled and replaced the oven control board at a cost of over $500 instead of buying my wife a new range. I should have bought 500 lottery tickets on my way to buying a new range. Any suggestions will be greatly appreciated.

Note: After writing this, I double checked the oven to see if it would ignite. It lit on the first try but shut down after 2 minutes. However, it started right back up after I turned everything off and then back on. It must know my wife wants to get rid of it. I think it is possessed!