Cannot connect new 7740 printer to my windows 8.1 laptop

[MarianW36]

II am trying to connect my new printer to my laptop so it can print wirelessly. I followed all the instructions to set up the printer and it recognises my network, correct IP address, WiFi-Direct appears in my network.  The printer however appeared as a greyed out icon in 'my devices' and was not an option in my document print menu.

Thinking it might help, I then tried to set up from the HPEasyStart (!) using a cable from printer to laptop. This worked inasmuch as the printer was visible in both 'my devices' and from the document, I was able to print. However this only printed whilst connected via  printer cable which is useless to me.

I've now set up the printer manually via 'add a device' - the printer now appears there with a tick to show it is the default printer but it failed to print the automatic test page which I stuck in the print queue!

If anyone can shed any light I'd be very grateful. I have set up umpteen printers before and this HP one replaces another HP printer (I have deleted all trace of the older printer & its software) so I'm not sure what I'm missing.

Thanks in advance.

[MarianW36]

ISSUE RESOLVED!

Thinking there might be an issue with a dual band router, I came across this item:

https://h30434.www3.hp.com/t5/Printer-Setup-Software-Drivers/Unable-to-print-with-dual-band-wifi-rou...

I followed the advice in the final entry to TCP/IP printer, specifying the IP address of the printer using the "add printer" function.  Lo & behold, after struggling for hours I finally got a document to print from the laptop - and as the entry says, it doesn't matter whether 2.4ghz or 5ghz!