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you need to be more specific , whatparts connected to what - how is the motor connected etc etc.
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the normal fault finding routine would be to connect one "part" at a time and check it to identify what particular item causes the problem - if you do that come back with " when I connect item X, to pins.... then I can no longer upload a program or cannot use the serial
monitor or whatever -
do you have something connected to the pins used for tx/rx? that will stop you uploading via the USB.