My multiplus is dead and does not light any leds. The main fuse is good, the switch checks ok, the 30 amp breaker is fine. Both AC and DC input tests ok. The unit will not pass thru the AC input. Is there a proper wiring diagram available? Any thoughts on how to troubleshoot? Beyond warranty repair, and have been told by distributers to buy a new one without them even looking at it. These should not be disposable. thanks