I tried but I think it's useless mainly because the gtm cable is not detected: in settings, traffic i see "TRAFFIC: enables traffic - traffic receiver cable required". But the cable is plugged in.
Connecting the usb the garmin detects the power source (coming from the 12V car adapter) but not the gmt. plugging or unplugging the gmt cable doesn't change anything.
I tried to restore the original 140.bin, no improvements.
In the hidden menu I've seen the FML number, I hope this is good news.