The Compute Module 4 or 5 might not be seated correctly.

1. Open the Yellow case and check if the green PCB (CM4 or CM5) is parallel to the Yellow PCB.

2. If this is not the case, check if the compute module is well aligned with the white outline on the Yellow PCB.
   • If the module is not aligned, align it first before pressing onto the heat-sink.
     • For that you will have to remove the heat-sink first.
   • If the green PCB is aligned, press onto the heat-sink on the two marked spots (centered above the CPU/SoC) to snap the green compute module in place.