My wife sprayed some Windex counter spray on the keyboard and then this started happening.
I have a Macbook that will only boot into Windows. I also have to attach a separate keyboard to type in the password. The caps stay on if I don't use a usb keyboard and my password won't work. But even with the USB keyboard when I hold down the Option key it doesn't give me the option to boot to the MAC, it goes directly into Windows.
I'm able to see the Mac partition when in Windows, just can't boot to it.