Hi all, hoping for some help on a stubborn one. I’ve done extensive diagnosis and I’m now stuck at what feels like the last step.
System:
· Victron EasySolar-II 48/5000/70-50 MPPT 250/100 GX (PMP482507010)
· 4× Pylontech US3000C (48V, 14.2 kWh total), CAN-bus to GX
· 16× QCell 415W panels (~130V array)
· Off-grid, installed ~2 years ago, worked perfectly for the first year
Fault:
· One day the system tripped. On restart, the inverter side showed “Status Off” alternating with “Status #3”
· The MPPT charger continues to work perfectly (batteries charge to correct voltage, currently sitting at ~52V, SOC ~85%)
· The Multi will not invert under any circumstances
· Physical rocker switch on the unit is completely unresponsive when set to II (charger only)
· Remote on/off terminal is shorted (factory default link in place)
Dealer history:
· Dealer took the unit in, tested it on their bench with lead-acid batteries — they got it to invert successfully
· They also flashed firmware to latest version
· Returned it to me. Upon reinstallation in my system, same fault returned immediately
What I’ve verified is working / correctly configured:
· VE.Can port state: ERROR-ACTIVE (normal), 55,000+ RX packets from Pylontech, TEC/REC both 0. Communication is happening.
· DVCC: Forced on
· CAN-bus profile: CAN-bus BMS LV (500 kbit/s)
· Battery Monitor: Pylontech battery on CAN-bus
· MPPT battery preset: Smart Lithium (LiFePo4), BMS controlled: Yes
· MPPT is correctly obeying BMS voltage limits (charging to ~52.2V, not its configured 56.8V), confirming DVCC is passing data through to the MPPT
· No alarms showing in the Device List
· Pylontech battery does NOT show “Allow to discharge” field in Device List (which I understand should be present with full BMS integration)
What I’ve tried (all no change):
· Full cold reboot (5+ minutes fully powered down, restart in correct order: master Pylontech first, then others, then DC, then PV, then AC)
· “Start without Assistants” button (held during power-up) — no effect
· Physical rocker switch cycling — no response from unit at any position
· Verified remote on/off terminal link in place
MK3-USB diagnostic (today):
· Bought an MK3-USB, connected to Mac via VictronConnect
· Mac sees the adapter at /dev/tty.usbserial-HQ2337UDXMY
· Cable is factory RJ45 patch cable, plugged into VE.Bus port on EasySolar
· Main Device List shows “VE.Bus device — Can’t connect”
· “Force detection” finds the Multi and reports “MultiPlus-II found, press to update”
· Entered dealer password (zzz), proceeded to update prompt
· VictronConnect then reports: “Your product is already running the latest firmware version”
· Clicking the manual re-flash icon (top right) asks for a .vff file, which I don’t have
· Normal click on VE.Bus device still returns “Can’t connect”
My interpretation: The Multi is alive enough to report its firmware version via Force detection, but not responsive enough for normal VictronConnect operations. Firmware is not corrupted. Feels like a stuck configuration state rather than hardware failure — possibly a leftover parallel/3-phase config, a misconfigured Assistant from when the dealer flashed it, or something else blocking normal VE.Bus communication.
Questions for the community:
1. How can I force a factory reset of the Multi’s configuration via VictronConnect/VEConfigure when I can’t connect to it normally?
2. Is there a way to get a .vff firmware file manually to force a re-flash of the same version, which would reset settings to factory defaults?
3. Any other recovery paths I’m missing?
Any help gratefully received. Happy to provide more info or screenshots on request.
