genie tmz34/19 issues

Hi I recently got a second hand non functional genie tmz34/19 lift yr 2000 serial number t3400-250 with original green boards, manual outriggers. There was no response when you turned it on. On inspection of the circuit board there was a line burn out on the pcb between "switches"(middle pin) and "platform controls"(second from the left pin). I jumped the 2 pins together and now the control panel powers up the leg leveling lights are illuminated and the unit is level but the only thing that works is the horn. I have unplugged all connectors/ribbon cables and re plugged them in but no difference. Any suggestions on how to diagnose the problem? or do i need to buy the blue board upgrade? The motor does work-whilst replugging in the circuit board it powered up for a few seconds. any help would be appreciated thanks joe