Have a electric bike Manufactured by Doohan (China)it has a 60 volt bosh motor. 60 volt 26 amp lithium battery pack ...also has a DC-DC converter ,for lights and display .. the Doohan only have 1 outlet here in the Philippines. and have not been able to get anyone to look at the bike and by all accounts they do not have spare parts in this county anyway. The motor works fine and always has, but since day one the display has always been hit and miss , had to unplug battery and reconnect sometimes to get display to work but last few weeks no display and headlight only flash,s, front side lights do not turn on .(all rear lights work ,tail,signal,stop.all working .) no signal at front or side lights only headlight flash,s (main beam and dipped same)all wiring has been checked and all electrical plugs seem to be okay all been cleaned with electronic cleaner. and re plugged back together, some times after travelling for 30 to 45 minutes display comes back on ,but after resting and recharging battery ,display goes off again . could this be the DC-DC controller or bad wiring ,how can I check it.??