Let me take a moment to thank you for posting on the HP Support Forums.
I understand that you have an HP DeskJet 3700 All-in-One Printer and it keeps repeating a previous print job over and over again. I read that you have tried clearing the printers on your computer and unplugging the power ad issue persists. I appreciate the steps you have performed and have certainly done a good job.
To provide an accurate resolution, I need a few more details:
Does the printer print the last print job over and over again?
Or is the last print job stuck in the print queue on your computer?
Meanwhile, I did some research and suggest you to perform the following steps:
Disconnect the power cable from the printer while the printer is still ON.
Disconnect any other cables if connected the printer.
Press and hold the printer’s power button for 15 seconds.
The printer should be directly connected to the wall outlet and not to a surge protector. Reconnect the power cable to print and the printer should power ON by itself. If the printer doesn’t power ON then please manually power it ON.
Now, please download and run the HP Print and Scan Doctor software. This program will detect and fix any printer drivers related issues.
I sincerely hope this fixes the issue. Feel free to reply with the results. All the best! 🙂