I have just encountered exactly same issue.
Havent installed the software, just hooked up 2 units and it worked fine off the bat.
Nothing changed in house, applicances and such, anything power related.
Then about 6-8 weeks later (few days ago), just stopped working, and no PLC-Link showing anymore. Have tried all the usual things like you say, no luck.
Strange how it stopped for no reason, is this perhaps a power surge killed something?
