You're right about the different bands having different components to choose the various frequencies, and that looks like where your problem lies. Not an easy fix. In the old days, each band was made up of discrete components that had tuning capabilites, so when you identified a circuit, you could tweek it, although it usually required complex signal generators and an oscilloscope, at least. These days, the components are largely ICs and surface mount ceramics- things that require replacement, versus re-tuning. It's probably cheaper to buy a new radio than have it fixed, but you can check. Eton's support page is here:
http://www.etoncorp.com/CustomerSupport
Hopefully, they will replace it for you, depending on how long you've had it, etc.
Wish I had an easy "fix", but good luck, thanks for using FixYa, and hope this helps.