Hi
Try to measure the voltage across the 2 “pads” of the film pack. This should read 6V. If this is not the case, then the battery inside the film pack is dead.
Alternatively, you can try to make a test film pack : https://www.youtube.com/watch?app=desktop&v=mJ19Ucit3S8
If all checks out but the camera still refuses to turn on, I would dab a swab in Isopropyl alcohol and clean the contacts inside the camera.
Cheers!
Bogdan