Self-ISP on an Uno

Be Very careful of using 'mini' dip switches... they have a reputation for Failure when frequently or infrequently used.
Back in the day, before I retired I had occasion to use them (Dip Switches and hand soldering would 'kill them' regularly
if they were for example not all off or on, I can't remember now which but after 2 'failed, intermittent design's I quit
specifying them in my work.

Doc.