I have an existing circuit board that, in production, we flash the two onboard microcontrollers. Currently we have a 1206 SMT pad which is open initially, the programming takes place, and then zero ohm jumpers are placed on those open pads.

Essentially we have FOUR nets that must be disconnected from the normal circuit during the programming process.

So i'm just hoping to gather up some ideas about how to automate this process without adding to the cost.

Two of the nets are power nets (+5v and +3.3v) so I'm not too sure if the above suggestions would work. Although the two I/O lines (Rx and Tx) I think will be easily disconnected via one of the above recommendations.