Before
Move JC31 to JC30 to change DS1 to DS0, clean the solder blob from SH1, cut the trace going to pin 34 on the data connector.
Solder a wire from the edgemost pad of SH1 to the solder point near CN6, solder a wire from pin 34 of the data connector to the test point near IC2.
Here are the modified areas circled.
Researched by Anssi Luukkonen