Yes, a full switch test is in order (whole machine). Could be a switch matrix issue too.
Test all the easy stuff first, then report back.
I put together a white paper on the MPF.
https://sites.google.com/site/pinballfaz/
Scroll to the bottom to select the document.
Even if you don't have to take it all apart it can help you visualize the bits better (IMO).
faz