Factory reset an HP 5510 Multi Function Printer - SOLVED

Just a heads up that may help someone.

I have a wireless HP 5510 printer and wanted to do a Full Factory reset.
I had found info about removing an internal battery but that involved dismantling the whole thing.

The following procedure is not invasive and works on a number of different models.

Background:
The touch panel key layout outside the display area.
Top left is the Home key.
Bottom left the Back key.
Bottom right the Cancel key.

There are three key positions along the bottom of the display area,

hese are dynamic and their function depend on the menu you have selected.

How to do a full Factory reset.
Switch on the printer and it eventually shows the home screen.
Now in this order press
back -
home -
back -
Cancel(X) -
back

The touch screen now shows the support menu.
use the right arrow to select the reset menu and OK
then select the full reset and press OK
Job done.

Unfortunately for me, the OK key doesn't work so I can't do anything that needs that third bottom key inside the display area - Bah!

There is a batch issue (loads of people have the touch screen problem) but hp do not want to know!

Good ole Google, found this:-

Here is the solution!

Download the hp all-in-one remote app to your smart phone/ tablet.

This allows you to do all the important things that you should be able to do on the printer touch screen.

I also had a problem when I changed WiFi router as you normally have to use the touchscreen to enter the new password.

But you can do this via a USB cable to a PC .