My touch screen on my Envy 7640 all-in-one does not work.

[karibkitty]

After a few months, my touch screen stopped working.  Also cannot scan or feed documents to print.  We have uninstalled and reinstalled, updated, and the touch screen still does not work.  Printer is useless unless we are printing a document from the computer.

[A4Apollo · Accepted solution]

Hey there! @karibkitty, Thanks for stopping by the HP Support Forums! 

I understand when you power on the printer the printer control panel has stopped working.

Don't worry I'll to help you out.

Did you make any changes to your printer?

Please provide the operating system you are running on your PC to assist you better.

As you mentioned when you power on the printer the printer control panel has stopped working.

Try the steps recommended below.

Turn on the printer.
Wait until the printer is idle and silent before you continue.
Disconnect the USB cable from the rear of the printer. If your printer has a network or wireless connection, leave it connected.
Remove the ink cartridges from the printer.
With the printer turned on, disconnect the power cord from the rear of the printer and from the wall outlet or power strip.
Wait at least 60 seconds.
Plug the power cord back into the wall outlet.
   NOTE:
HP recommends connecting the printer power cord directly to a wall outlet.
Reconnect the power cord to the rear of the printer.
Turn on the printer, if it does not automatically turn on.
The printer might go through a warm-up period. The printer lights might flash, and the carriage might move.
Wait until the warm-up period finishes and your printer is idle and silent before you proceed.
Reinsert the ink cartridges, and then close the ink cartridge access door.
If you receive a prompt to print a calibration page, do so.
If you disconnected the USB cable, reconnect it to the rear of the printer.
Try to print.

Also, try updating the printer firmware and check if it helps.

Link to update the printer firmware.

If the issue still persists after trying out the steps.

It is a hardware issue with your printer.

Please contact HP support for service options.

Link to contact HP.

If the solution provided worked for you, please mark accepted solution for this post.

Let me know if this helps! 
Have a pleasant day ahead! 🙂

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[Ferrier2011]

This still didn't work for me.  

Any other ideas?  The touch screen is possessed even sometimes.  Just shuts on/off, flips through screens, etc.

I really need it to be able to scan but I can't ever get it to even work when I touch the scan button.  Frustrated.  It's been months of it not working.

[psavage]

This solution worked for me

[VaCaspicom]

h solution exactly worked for you?