DC 1250 Paper Jam when printing few copies

Unfortunately, 2-sided printing is only available for the Epson L20 when used with the Windows OS. See page 22 of the user guide available here: https://www.epson.com.ph/Ink-Tank-Printers/L-Series/Epson-L120/s/SPT_C11CD76401?review-filter=Mac+OS+X+10.11.x#manuals . The current link to the manual is http://support2.epson.net/manuals/english/ij/l120/pdf/npd4965-00.pdf . You might be able to use the Duplex feature if you install BootCamp and an licensed version of Windows (XP up to WIndows 10). Neither BootCamp or licensed copies of Windows are free.

I wish that I had better news for you.

Cindy Wells

check between the rollers there will be small bits of paper jammed in that is the reason.

Hi clean all rubber rollers in duplex with rubber solution then fan paper and make sure paper curl is facing down everything will be ok then

I just returned my HL-5370DW printer to Staples. I only had it for 3 days and found it running hot, warping card stock and envelopes, and jamming regular size paper constantly. It appears to be OK for very small print jobs but not very robust. I did like the duplex printing and the price. I do not believe there is a solution other than replacing this printer.
Xelzbear

Your manual can be found here.

Printing on both sides of paper You can print on both sides of a paper; duplex. Before printing, decide how you want your document oriented. You can only use this feature with Letter, Legal, A4, US Folio, or Oficio sized paper.


Do not print on both sides of the special media, such as labels, envelopes, or thick paper to print on both sides of paper. It may cause a paper jam or damage the machine.

1. To change the print settings from your software application, access Printing Preferences. (See Opening Printing Preferences.)
   
2. Click the Layout tab.
   
3. From the Double-sided Printing section, select the binding option you want.
   
   • Printer Default: If you select this option, this feature is determined by the setting you’ve made on the control panel of the machine.
     
   • None
     
   • Long Edge: This option is the conventional layout used in bookbinding.
     
     
   • Short Edge: This option is the conventional layout used in calendars.
     
     
   • Reverse Double-Sided Printing: Check this option to reverse the print order when duplex printing.
     
4. Click the Paper tab, select the Paper Options.
   
5. Click OK or Print until you exit the Print window.
   

If your machine does not have a duplex unit, you should complete the printing job manually. The machine prints every other page of the document first. After that , a message appears on your computer. Follow the on-screen instructions to complete the printing job.

Good Luck!

Jesse

What printer are you using? Many printers cannot print two-sided or duplex printing. If your printer cannot handle duplex printing, you'll need to do what's called "manual" duplex. Print one page then reinsert the paper and print the second page. Test this on cheap paper first to determine if you need to insert the paper printed side up and which way (if any) you'll need to roate the page.

The MP610 does support duplex printing.

Duplex Printing

The duplex printing function allows you to print data on both sides of a sheet of paper.
The procedure for performing duplex printing is as follows:
Performing automatic duplex printing
You can perform the duplex printing without having to turn over the paper.
1. Open the printer driver setup window, check the Duplex Printing check box, and confirm that Automatic is checked.

2. Select Normal-size Printing (or Fit-to-Page Printing, Scaled Printing or Page Layout Printing) from the Page Layout list.
3. When printing a document that has small margins, click Print Area Setup... and set the print area.
When you perform duplex printing, the print area of the document becomes slightly narrower than usual and the document may not fit on one page.

To print without reducing the page:
Select Use normal-size printing.
To reduce the page slightly during printing:
Select Use reduced printing.
4. Specify Staple Side.
The printer analyzes the Orientation and Page Layout settings, and automatically selects the best staple position. Check the Staple Side setting. If you want to change the setting, select another value from the list.
5. If necessary, click Specify Margin... and set the Margin width.
6. Click OK.
Duplex printing will be started.

Performing duplex printing manually
You can perform the duplex printing manually.
1. Check the Duplex Printing check box and uncheck the Automatic check box on the Page Setup tab.

2. Select Normal-size Printing (or Fit-to-Page Printing, Scaled Printing or Page Layout Printing) from the Page Layout list.
3. Specify Staple Side.
The printer analyzes the Orientation and Page Layout settings, and automatically selects the best staple position. Check the Staple Side setting. If you want to change the setting, select another value from the list.
4. If necessary, click Specify Margin... and set the Margin width.
5. Click OK.
If a media type other than Photo Paper Plus Double Sided is selected for Media Type on the Main tab:
When you execute print, the document will be printed on one side of a sheet of paper. When printing is complete, reload paper according to the displayed message and then click OK. The document will be printed on the opposite side.
If Photo Paper Plus Double Sided is selected for Media Type on the Main tab:
When you execute print, the document will be printed front and back alternately for one sheet at a time. Load the paper according to the displayed messages.
Note Duplex Printing is unavailable when:
- A media type other than Plain Paper, Photo Paper Plus Double Sided or Hagaki is selected from the Media Type list.
- Poster Printing is selected from the Page Layout list.
When Booklet Printing is selected from the Page Layout list, Duplex Printing and Staple Side appear grayed out and are unavailable.
After printing the front page, there is an ink drying wait time before starting to print the back page (Operation stops temporarily). Do not touch the paper during the time. You can change the Ink Drying Wait Time at Custom Settings on the Maintenance tab of the printer driver.
When you perform the automatic duplex printing for Hagaki, print an address first and then print your message.
Tip If you select Photo Paper Plus Double Sided for Media Type on the Main tab, the Duplex Printing check box on the Page Setup tab is not checked automatically. To perform duplex printing, check the Duplex Printing check box.
If the Media Type dialog box appears when performing borderless printing during duplex printing, select Plain Paper or Photo Paper Plus Double Sided.
When performing the automatic duplex printing, do not use any plain paper smaller than A5. Also, do not select any type of paper other than Plain Paper, Photo Paper Plus Double Sided or Hagaki at Media Type.
Photo Paper Plus Double Sided is highly recommended for printing photographs on both sides of a page.
If the back side of the paper becomes smudged during duplex printing, perform Bottom Plate Cleaning in the Maintenance tab.

http://www.brother-usa.com/ModelDocuments/Consumer/Software%20Users%20Manual/SUM_DCP_7030_7040_MFC_7340_7345N_7440N_7840W_EN_1650.PDF

here is the manual p4 and p16 discuss the topic:
Duplex printing 1
The supplied printer driver supports duplex printing.
Guidelines for printing on both sides of the paper 1
�� If the paper is thin, it may wrinkle.
�� If paper is curled, turn over the stack, straighten it and then put it back in the paper tray or the Manual Feed
Slot.
�� If the paper is not feeding properly, it may be curled. Remove the paper, straighten it and turn over the
stack.
�� When you use the manual duplex function, it is possible that there may be paper jams or poor print quality.
If there is a paper jam, see Paper jams in the User’s Guide. If you have a print quality problem, see
Improving the print quality in the User’s Guide.
Manual duplex printing 1
The machine prints all the even-numbered pages on one side of the paper first. Then, the Windows® driver
instructs you (with a pop-up message) to reinsert the paper. Before reinserting the paper, straighten it well,
or you may get a paper jam. Very thin or thick paper is not recommended.
Simultaneous scanning, printing and faxing 1
Your machine can print from your computer while sending or receiving a fax in memory, or while scanning a
document into the computer. Fax sending will not be stopped during PC printing. However, when the machine
is copying or receiving a fax on paper, it pauses the PC printing operation, and then continues printing when
copying or fax receiving has finished.


�� Manual Duplex
Check Manual Duplex. In this mode, the machine prints all the even numbered pages first. Then the
printer driver stops and shows the instructions required to re-install the paper. When you click OK the odd
numbered pages are printed. There are six types of manual duplex binding directions available for each
orientation.
�� Booklet Printing
When you want to print a booklet, use this function. To make the booklet, fold the printed pages down the
middle.
�� Binding Offset
If you check the Binding Offset option, you can also specify the offset for binding in inches or millimeters

check the driver

does not print from bypass tray (manual feed)
does not print on thick paper (check paper type)

HI there sounds like there is a blockage in the duplex area that is not holding any sensors down. Check the duplex area for torn paper, failing this it maybe a sensor problem which will then need a engineer.

Hope this helps
Thanks J