UPDATE: PLEASE SEE PB474 CONCERNING A SPECIFICATION CHANGE FOR THE DPF-300 FUSES FOR F1 AND F4.

There could be several reasons why this fuse is blowing.

First, check to see that there is no debris in the milling bit. To do this, take off the guide and head. Rotate the milling bit to see if it can turn freely. If it is not moving freely, clear any debris that is in the milling bit. There is a spacer in the milling bit. Do not take this spacer out.

 If that is not the case then the unit will have to be opened. A new fuse will need to be installed in order to perform the following procedure.

     1) To do this, get a M4 hex wrench and unscrew the 3 screws holding the front panel on.