The most likely issue is not a dead CF card or LCD, but a problem introduced during reassembly — especially a ribbon cable or connector related to the sensor board.

Based on the symptoms, the camera is still powering up and operating normally enough to review old images, so the first things to check are:

• whether you were properly grounded during the work
• whether any ribbon cables were reinstalled backwards, incompletely, or not fully latched
• whether cables between the sensor board and main PCB were stressed, loosened, or damaged

A practical next step is to reopen the camera and carefully reseat every relevant ribbon cable and connector, especially around the sensor assembly. Inspect for flipped cables, partially inserted ribbons, or damaged flex cables.

It’s difficult to confirm a failed sensor board without substitution testing. If reseating connections does not help, the usual way to verify sensor-board failure is to swap in a known-good part from a donor/parts camera. Without that, you’re mostly guessing.

So: start with connection checks and careful reassembly; only after that should you suspect the sensor board itself.