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The printer was connected by wifi to my previous router, though it was acting up; when the new router was added it appeared that there was a problem with one of the wires, so everything is now connected to a different set of plugs, I hoped this would make it work. The wifi connection to my laptop is now fine - previously it was intermittent. The printer is a couple of feet away from the router, on the same desk surface. Fortified by a glass of fermented grape juice, I followed the instructions on the link you sent, Togo (thank you very much) but the wifi icon on the printer is blinking and I suspect it should be steady; it won't print, anyway.
I think I'll switch it all off and try again tomorrow, in the hope that Spicerack's experience will be repeated. Many thanks for the advice.