ok after a simple google search on the zapi sem2 i found this for you

6 flashes can mean either one of the following 4 things

1) CONTACTOR DRIVER Problem with a Contactor Driver in logic.
2) COIL SHORTED Short Circuit of Contactor Coil.
3) DRIVER SHORTED Short Circuit of Driver supplying the Main
Contactor.
4) CONTACTOR CLOSED Main Contactor contacts CLOSED. Contacts
may be welded or mechanical failure has

my guess is you have either welded tips on the line contactor or its shorted and probably needs to be replaced.
occoured.