Milwaukee 2780-20 M18 Fuel 4-1/2"/5" Grinder - Red

Motor turns on intermittently and will not shut off normally; only stops when battery is removed. Likely trigger switch or power control malfunction.

The stated fault does not map to a single common repair part, so treat this as a parts or board-level unit and confirm the real cost before buying. The common failure points for this kind of item are below for reference. Subtract the relevant one from the $111 margin to gauge the real spread.

Common faults for this model

• Dead battery pack$25 to $60eBayAmazon
• Trigger / switch$10 to $25eBayAmazon
• Chuck$15 to $35eBayAmazon
• Motor brushes$8 to $20eBayAmazon
• Motor / armature$30 to $60eBayAmazon

Repair costs are rough parts estimates, not a diagnosis of this exact unit. Confirm the fault and your repair path before you buy.