The boards are normally part of the light unit and not sold separately.
Please provide some more details, i.e. pre-face lift, face lift, 3/5 dr or ST Estate, LED or non-LED, RHD or LHD, Nearside or Offside, Outer or Inner unit (on hatch lid or rear wing fitment).
A decent vehicle electrician may be able to provide a continuity check and/or repair tracks/wires/connections. However, also need to establish root cause of failure - water ingress, vibration etc.