Printer keeps going offline

The printer is an HP Envy 5640 and has worked fine wifi connected to my home router for the last 2 years.

Suddenly it has gone offline.

1) restart printer (power off - power on) printer is back on line.

2) print a couple of items

3) printer is off line

When I print the diagnostics page (directly on printer) everything appears to be OK.

My assumption is that the problem is with the printer. Has it "died"? Not happy about it's life expectancy if this is the case.

I read an old article which said that it could be a problem with SNMP where SNMP stands for Simple Network Management Protocol and is a way of getting information from network devices (such as routers, servers and printers), mainly for the purposes of finding out if there are any problems with the devices. A number of networked printers implement SNMP, and will respond to SNMP queries with information, but some don’t.

I wondered if my HP printer has a 'fault' and is simply not responding to an SNMP request in time so OSX is assuming the printer is "offline".

If this is the case how do I turn off SNMP for this device?