Deskjet 3700. On my mobile app it says jammed

[Jonesz2488]

Brand new never been used. There is a post in the bottom of the printer that is keeping the ink from slinging across. Mobile app says jammed. Printer says error 3

[A4Apollo]

Hey there! @Jonesz2488, Thanks for stopping by HP forums!

I understand when you print from your mobile you are getting error jammed. Also, you are getting error 3 on your printer.

Don't worry I'd love to help you out.

Did you make any changes to your printer?

What app are you using on your mobile phone?

Please try the steps recommended below.

Resetting the printer can clear carriage jam errors.
Turn the printer on, if it is not already on.
Wait until the printer is idle and silent before you continue.
With the printer turned on, disconnect the power cord from the rear of the printer.
Unplug the power cord from the wall outlet.
Wait at least 60 seconds.
Plug the power cord back into the wall outlet.
   NOTE:
HP recommends connecting the printer power cord directly to the 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.
Try to print. 

Refer this article to further troubleshoot E3' Errors on your printer.

Let me know how it goes!

Have a wonderful day ahead! 🙂