Hopefully it’s easy to fix! The signals from shift register IC4 onwards are missing so you can check:
The output pin of IC3 (pin 9)
The input pin of IC 4 (pin 14), also power (pin 16) and 0V (pin 8).
The serial clock and shift-out are in parallel, so I don’t think it’s that. My guess is that one or more of the pins are cold-soldered or shorted to the adjacent one.