"Tim, normally we suggest to people to stay away from the microwave repair. I guess in your case, and since you are already up to your armpits in it, it is okay to suggest something. get the service manual from here. It does have the diagrams as well as parts description etc. The troubleshooting section says that:""
1. Oven is dead.
Fuse is OK
No display and no operation at all.
1. Open or loose lead wire harness.
2. Open low voltage transformer.
3. Defective DPC AU or DPC DU
Again, please be careful, would not want you to get zapped (or is it fried:-) anyhow, good luck. hope this helps."