The AG-1980 is supposed to have a built in head cleaner though. At least the early models were advertised as having it. My second generation model has some minor design differences from the one I bought in 1997.
There's also the "play a brand new blank tape all the way to the end" trick I learned in college. Unless someone has been putting greasy nasty rental tapes in the machine, the heads usually don't have major problems.