Typically, there's nothing electrical from the lmi that will stop the crane from retracting- the LMI will stop boom down, cable up, and telescope out- all to stop overload. There's typically nothing to stop boom up, cable down, and telescope in from the LMI.
That's not to say that there isn't a solenoid control for pilot pressure that has to work for individual functions in either direction, if its a pilot or electric over hydraulic machine. If its electric over hydraulic joysticks, it could be a joystick issue.
Either way- it shouldn't be anything exotic- Terex wasn't making the valve stacks themselves, so you should be able to source the solenoids without too much trouble.
If it is the LMI shutting you down, you should be able to work around the system by 12v bypassing the signal shut off. Of course the LMI won't turn you off for any overload conditions with it bypassed, but it would get you running.