ZahidSolo

Good Morning I am zahidSolo, I Read the helpful Description Of Error %1 In Solar Inverter. I really Need help, I have Master In Electronics, but Now My Tong Came Out, I have similar Problem, I have Two Inverters Of Similar Fronus 4.2KW PV500 , System Control Board Exchanged and is OK, MPPT Board Exchanged And Is OK, All Supplies +12v, -!2V ,5v , Even On System Board ,5V, 3.3V all are stable noise free checked with Oscilloscope. The Problem---- I have no Battery, Just want to make 230v Ac from Solar, But as soon as I switch On, Soft Start Increase DC BUS to 380 Volts then Immediately Unit Display restart with a loud Sound from Relays, or It give Error 51 Dc to Ac converting IGBTs replaced, opto-Coupler drivers Replaced , Checked all connections, Even Now I has Drawn Almost Complete Circuit Diagram, I am comparing It With Working Inverter of Same Model , Every Thing same Except It Gives Error, I removed every Component From Output side Like MOV1, MOV2 and C58 Since Many Days I am Trying, I really Need Help From Experts Thanks