Stubborn 'Paper Mismatch' error. [SOLVED]

[momist]

This fault is independant of computer operating systems and drivers, as it seemed to affect ALL printing, including the internal forms and reports generated by the printer itself. 

After requesting the printing of a pdf form from my bank, which failed to print, I found that the printer would no longer print at A4 or Letter size, but seemed happy to print at A5 and other smaller sizes, no matter what size paper was loaded.  The error given was:

"Paper Mismatch",

and an 'OK' acknowledgement just brought it back to the home display and the document was cancelled.  When I went into the tools menu and tried to print the 'Printer Status' report, the same error occurred but the 'OK' now caused a re-try which also failed.

Strangely, Photo printing (6 x 4) worked OK, and so did copying from the scanner at A4.  When I came here to the forums to research this problem, I ended up going round in circles doing 'hard resets', changing sizes of paper etc., together with a lot of mis-direction about menus and facilities not present on my model of printer.  There have been an awful lot of complaints about this fault that have gone unresolved.  Cynically, perhaps HP are quite happy for people to throw away their printers?

Eventually, after investigating my options for buying a replacement printer, I tried a general internet search for the problem, with the terms "HP printer paper mismatch", and turned up a very old post from four years ago for a totally different unrelated model of HP inkjet printer.  The guy with this problem eventually decided to try every possible command on the printer interface (just for the fun of it?) and strangely discovered that changing the Scan function to 'Draft' setting (even though, like me, copying was working normally), cleared the 'Paper Mismatch' fault entirely.

So I tried that myself, and for good measure set the default printing to 'Draft' as well.  Voila!  My printer now worked normally, and so far the fault has not returned.

I am posting this simply to inform others, as it appears that this fault lies somewhere in the Firmware and afflicts multiple models of the HP inkjet range.  I sincerely hope that it helps someone.  I wonder just how many printers have now been trashed for this bug, that could still be in use?  If I have saved only one from going to landfill this will be a success.