Conveyor Drive Motor Brushes OK
The brushes should be replaced if they have worn less than 1/4'' (6.4mm) in length. Be sure to replace the brushes in exactly the same position
Burner nozzle and electrode assembly clean (For has ovens only)
Oven venting system clean and OK
Conveyor drive shaft bushings and spacers OK
Replace the components if they are worn.
Source: Middleby Marshall