Esna

Good day, I have a Mecer sol-i-ax-5m4 that had firmware version 72.00 on. I replaced a pylon tech UP5000 with 2 Greenrich U-P5000. When both these batteries were fully charged i started to have like a reboot trip on the inverter. First it was every 30 odd minutes than a bit longer and then again 30 odd minutes. I tried using I tried using only one than the other to eliminate a faulty battery. Still no change. Disable the auto restart for overload and over temp to see if either is causing the "reboot" Nothing seems to cause the trip, to a point where I switched off the batteries. Reading numerous pages on comments I tried the suggestion of updating my firmware to version 74. Got the link on a previous post and tried to flash with version 74.40e. The flash failed on 99%. tried to reflash with no luck. I now have a machine that sounds like it is about to take off with no active display. I tried to flash to a previous version 72.00a as well as 73.00, even tried the MCU update with no luck. Any advise will be much appreciated as on other threads it seem that I now have a nice brick...