There’s no explicit instructions on the VT132 website for how to attach the optional USB addon board instead of the default PS/2 connector but there is an extremely details step by step video here.
Summarizing the additional steps:
- trim the 4 back legs of the USB connector so that it sits flush to the red addon board and make sure the pins don’t protrude from the board, then solder the back pins to the add on board and make sure the soldering is flush so it will sit flush to the main board
- solder the 2 larger outer pins from the back first, then the inside 2 pins
- the addon board attaches to the main board component side up
- push the black spacer of the 6 pin header all the way down so the spacer is flush to the end of the pins
- attach the row of header pins though the top of addon baord to the back; there shouldn’t be any length of the header pins extending on the top
- solder the header pins on the back of the addon board
- put a small strip of electrical tape across the bottom side of the addon board before inserting to main board before soldering, to avoid any contact with the original PS/2 connector pads on the circuit board
- insert the addon board, turn over and solder the pins
- solder the two front structural legs on the usb connector