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Hi all Hopefully someone can help , I got a dewalt dc390 cordless circular saw , and seems to run slow speed and has lack of strength when cutting , battery also seems to get very hot and takes ages to cool down . Now seems like a low power battery but I have 4 batteries 2 of which are new and same happens with each . I can just about cut a small piece of wood by using all batteries but each battery last max 30 sec - 1 min . Obviously there is some fault. With the circular saw . Does anyone have any idea what might be the cause . Spare parts are readly available and I can change myself but need to know how to test what part so I can order correct part ? Motor , armature, brushes ( but no sparks that I can see) etc Any suggestions much appriciated Thanks Mark
Mark Watts, “slow speed and has lack of strength " sounds like you are having issues with the motor. If it has shorted starter windings it can cause the issues you described. This could cause pulling to high amperage from your battery and cause those to become depleted and hot. Of course, you also want to check all the bearings since this could cause the motor to draw higher amperage as well.
This exact thing is happening to mine. I have no idea how to fix it
