I have used winkeyers for many years now, ever since building a serial version board to take on the 3B9C expedition without any trouble. While setting up a WKUSB-SMT at the MW2I station recently it refused to respond after a run on 20m. It appeared on the virtual com port but refused to respond to the wk3demo or wk3tools programs. I thought a reset was needed, but the manual was not very helpful as it suggested hitting the reset button when connected to the keyer, which I could not do. So I left the problem and substituted the spare winkeyer a WKUSB-DIP which worked fine.
A few days later I found the document https://www.k1elsystems.com/files/WKUSB3_restart.pdf on the winkey website which had a very interesting paragraph:-
There have been cases where a WKUSB‐SMT has entered a lock up state due to a nearby lightning strike,
a high RFI field, or other very unusual situation. In most cases the WKUSB can be restored to normal
operation by pressing and holding the red pushbutton for about six seconds until it responds with an R
followed a few seconds later with an OE (dah‐dah‐dah‐dit).
This technique was tried and the WKUSB-SMT recovered. It did reset the EEPROM so all settings had to be re-entered, but the crisis was over! Pity this information is not in the manual!