I found this on the GE website. An error of F7 means that there is something wrong with the key panel and it may need to be replaced. Here is the sheet of codes for you to look over - http://www.geappliances.com/search/google/infobase/10009792.htm. Here is the contact us page on the GE website as well in case you have more questions or need to know where you can go to get your oven serviced - http://www.geappliances.com/service_and_support/contact/.
Please let me know if you need any further information.