Take a look at the reel strips. Possibly one of them is hanging out and hitting the front glass or other part inside. This could explain the pear symbol.
If the machine doesn't stop on the symbol that's expected, it will set a tilt code. HOWEVER, it will only set the code if it doesn't stop on the expected symbol 2 out of 8 pulls. So, it could be something mechanical.
The code dictates where the symbols stop, and the reel symbols are strictly for amusement.
If there were a bad reader sensor, the tilt code would appear.
You can try swapping the reader cards, i.e. swap the card on the 3rd. reel with the card on the 1st. reel, etc. If the pear symbol moves, you might have an intermittent connection on the suspected card.