[Woogy]

My GE Profile gas stove was working fine in December. I moved, house sat vacant for 6 months. New tenant having problems with error code F1. Called home warranty to repair, they sent Sears. Claim was denied based on miscommunication with the tenant and repair guy.(repair guy said tenants claim problem happening BEFORE they moved in-makes no sense!) But that the control panel has a stuck button. So warranty company sends repair guy #2 out a few weeks later for a 2nd opinion. Now it is taking a long time for the oven to heat to temp. Stove top works fine. He says the gas flow is spuratic and there is a stuck button on the control panel. Diagnosis from #2 guy is control board, ignitor, touch panel, burner all need replaced. He states this couldn't all have gone wrong in 2 weeks, so the claim was denied as a pre-existing condition this time. Repair costs over $700. We want to get this fixed for our tenants, but from a distance it's hard to know where to start without buying unnecessary parts. The warranty company said they will pay for repair if we can show it was mis-diagnosed.
I admit I've only read a few posts, so am I wrong to think that one bad component could be what is causing other parts to not function?
Please help me with where to start! My tenants work with electronics, so they are willing to replace the parts.
Thanks,
Lisa