Check voltages at multiple points to eliminate an dead/faulty contactor, key switch or emergency stop switch, dead screen should/could be measured over CAN line as the can should have 60/120ohm resistance.
2009 is a tricky year as that could be a machine with screen behind the steering wheel or the orange screen next to steering column.
Lights work because probbaly they run under separate module that gets power from first K1 contactor or in case of non jungheinrich install are directly wired to machine side battery supply connection point.
What I'm probably trying to state is that it still could be general voltage or self test fail issue.