This page gives overall advice on how to assemble BlueSCSI V2 Desktop kits. These kits already have the surface-mount soldering completed. All that remains to be done are the through-hole connectors.
First important note: All headers must be installed with the short end through PCB, and long end sticking up away from the board. The mounting bracket won’t fit, and the jumpers won’t work, if installed incorrectly.
Second important note: Pay attention to the “USB” marker on the PCB. It points to where the USB port of the Raspberry Pi Pico module should be located. USB port goes by the BlueSCSI logo.
After doing the soldering, you must install two jumpers for the device to work properly. First, place a jumper on the PWR_ON header. Second, choose between termination on (TRM_ON) and off (TRM_OFF) and place your jumper across the marked pins.
See the main product image for how it should look when fully assembled.