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Im assuming you have the printer attached via a usb cord.. Is that correct? ( When it prints the two lines of gibberish)
If its a usb connection. lets repair the problem with these steps.
Click start, click devices and printers. Now right click any and all copies of your dell 1720 printer.
Delete / Remove them. Once removed.
next, go to the dell website and redownload the printer drivers. Here is the 64 bit driver, if you have a 64 bit version of windows. http://www.dell.com/support/home/us/en/04/Drivers/DriversDetails?driverId=R149580&fileId=2731116705&osCode=W764&productCode=dell-1720dn&languageCode=EN&categoryId=PR
Once you have the driver downloaded, open and install that file. And it will reinstall the printer onto y our computer.
At that point you should be able to print normally, without the Gibberish.
If you get stuck or run into any issues, let me know!
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