That could be the problem. Perhaps try another; the one from Jaycar (Australia and New Zealand) is known to work. [ Edit: It's since been established that the known-good Jaycar adapter also uses a PL2303 chip, so it's likely NOT to be the problem. ]
So far everything is perfectly normal. After that click, the normal software isn't running, so the LCD doesn't update at all. It will just freeze with whatever it was displaying before. The bootstrap loader has taken control.after about 5 seconds the inverter clicked once, output seems to go off although it still displays 230V output, and stopped blinking green (I had also disconnected solar and removed the output load, but left the inverter power switch on),
So something seems to be going wrong after the initial handshake.then after another 20 seconds or so the updater says "cannot connect to COM port!", and the inverter is stuck then and will not react to powering off, I had to disconnect the battery to get it back to running.
The command to initiate firmware updating is at 2400 bps, as are all commands and responses. However, the flash updating takes place at 9600 bps. It looks like your communications is marginal somehow, and fails at 9600 bps when it works fine at 2400 bps. After the PC program aborted the firmware update, the inverter must have been still attempting to communicate at 9600 bps. Hence the checkerboard pattern and lack of response. I think it would revert to normal operation, perhaps after a long timeout, but I'm not sure about this.After the first time I hadnt realized the inverter was frozen and I hooked up a terminal to the serial port and started receiving a crazy character (looks like a cursor-sized checkerboard pattern) about every second (possibly wrong baudrate, although terminal was set to 2400). No reaction to any keyboard input.
You will only get a U2 (SCC firmware version number) display if PV is connected and panels are producing power. So perhaps last week was at night, or the solar panels were isolated.Any ideas? My current firmware U1 is 72.60 and interestingly now I also get a U2=04.10 (didnt get that when I tried last week).
That sounds fine.My label says Effekta, AX-M 5000-48
Solar Charge 80A, Max open circuit 145V
My first suggestion is trying another USB to serial adapter. Id' say there is a 90% certainty that this will be the problem.
If that doesn't work, there is a chance that your communications board performing well enough for firmware updating. Some boards do seem to be better than others at 9600 bps, taking longer to complete firmware updates due to resending of bad packets. Assuming you don't have another machine to swap communications boards with, you'd have to order one from your supplier. If you're keen, you could attempt to replace the opto isolators on the communications board, though there is no guarantee that this would fix the problem.
[ Edit: "isn't up to" -> "performing well enough for" ]
[ Edit: Added sentence starting with "After the PC program aborted". ]