Sounds like you have a column out. That would be all the switches 31-38.
If you have the manual, look at the back of the book for the "Switch Matrix". If you don't have the book, download the PDF from IPDB.org.
Check the CPU connector J206, pin 3. It is Green and orange. Is it loose or has it fallen out of the connector ? Reseat the connector.
Check all the switches in that column - all the Pop bumpers, both LHS and RHS slingshots and the upper left loop. You are looking at the switch for a Green and Orange wire that has fallen off.
After following these steps - report back !
