What makes a printer print light on one side of paper?

i know you stated you put the paper in correctlyin the printer but if the thermal reactive side of the paper is not facing the print head the thermal paper won't print on the wrong side of the paper. it will load into the printer and seem ok but the heat on the wrong side of the paper will not react and show any writing. Can you try turning the paper over in the printer feed holder so the other side of the paper faces the print head and give it another test .

Try to remove toner cartridge and shake, plug in and make a self test print. if not work, you need to change new toner cartridge to make sure that the problem is not with printer itself.

Please follow steps below on how to print 2-sided on your printer:
Printing on both sides of the paper (duplexing) automatically:

1. Press .
2. With a document open, click File > Print.
3. Click Properties, Preferences, Options, or Setup.
4. Click the Print Layout tab
5. From the Duplexing area, select Use Printer Settings from the drop-down box.
6. Make sure the light is on.
7. Click OK to close any printer software dialogs that are open.

Printing on both sides of the paper (duplexing) manually:

1. With a document open, click File > Print.
2. Click Properties, Preferences, Options or Setup.
3. Click the Print Layout tab.
4. From the Duplexing area, select Manual from the drop-down box.
5. Select the Print manual duplex instructions check box.
6. Press Start.
7. The printer prints the odd-numbered pages and the instruction sheet, which describes how to flip and reload the paper.
8. Following the instruction sheet, flip and reload the paper with the printed side facing away from you.
9. The printer then prints the even-numbered pages on the reverse sides of the odd-numbered pages, completing the two-sided sheets.

Note:

• button is not functional with a Macintosh operating system. You can print two-sided documents with a Macintosh operating system by using the settings in the Two-Sided menu of the Print dialog.
• Automatic two-sided printing (duplexing) works only with plain paper in letter and A4 sizes. If you want to print two-sided documents on another size or type of paper, use the manual duplexing method.
• To return to single-sided printing, make sure the light is not on.

what is the error ?
does it says Paper jam, Open the print cover and remove paper jam..

If this the error repeating then make sure,

1. u r not overfilling the paper tray
2. put the printer on a hard surface (not on a half out surface)
3. from now on be gentle with the paper tray.
4. unplug the printer everytime u r done or atleast overnight.

thanks

Make sure your paper is not curved. Fan the paper and make sure it sits in the hopper evenly. Also make sure that when you were installing the printer you did not drop something or a piece of the packaging is not stuck in the side. Use a flash light to inspect the paper path

The iP4300 manual says this for 10 flashes "
The size of paper may not be compatible with automatic duplex printing. The sizes of media suitable for auto duplex printing are A4, Letter, A5, and 5" x 7". Make sure that the size of the paper loaded in the printer is correct. Pressing the RESUME/CANCEL button will eject the paper and restart printing from the front side of the next paper. The reverse side of the ejected sheet will not be printed." Hope this helps

First thing to check is that the paper guide at the back is set. I've seen so many printers (of all makes) where the guide is not set at all.
Put a stack 20 to 30 sheets in the rear paper tray. Make sure that the stack is snug up against the right hand side of the feed tray (as you look at it from the front).
Then, make sure that paper guide - the little light grey plastic sticky-up bit at the left hand side of the feed tray - is moved up snug to the stack of paper. It should touch the paper but not squeeze it. Now try printing.
That guide is what makes the paper stay straight. If it does not touch the paper then the paper will go out of line.
This applies to all makes of printer and all types of printer.

on note pad or word you should select the paper size first because it might set to a different size. when you click file click print click properties or printing preference and choose what size of paper you have in your tray and then click ok. print ok.
check the printer paper tray setting to make sure the paper tray side guide is right agains the paper. I hope this will solve your problem.

HH

The print carriage may get stuck on either side or in the middle of the printer. The Carriage Jam: Open Door, clear carriage jam, and then press OK to continue error message may display on the front panel of the all-in-one.

Solution
The print carriage is the device which contains the print head and moves left to right during printing.
Figure 1: Carriage Assembly

To resolve this issue, follow the steps below in the order presented.

Step one: Print a Self Test

Follow the steps below:
1. Press the Setup button.
2. Select Print Report and press OK .
3. The self-test page should print. If it prints a test page, there is no need to follow the remaining steps, as the error message may be false. Make sure the printer now prints from the computer (if installed on one). If it does not print, proceed to the step two.

Step two: Clear the paper path

Follow the steps below to clear the printer of any jammed paper and reset the printer.
1. Leave the printer on and then disconnect the power cable and the USB or Ethernet cable from the back of the printer. Do not reconnect them until instructed to later.

NOTE: Make sure the printer is on before disconnecting the power cord. Failure to disconnect the power cord from the rear of the unit can cause damage when removing jammed paper.

2. Open the top access door.

Figure 2: Opening the top access door

3. Make note of where the carriage is stuck and look for jammed paper. A paper jam can cause the error message and the carriage stall. Some paper may be jammed in different locations than those shown in the photos below.

Figure 3: Paper jammed on the left side

Figure 4: Top view of paper jammed on the left side

Figure 5: Paper jammed on the right side

Figure 6: Top view of paper jammed on the right side

NOTE: Do not use any tools or other devices to remove jammed paper. Always use caution when removing jammed paper from inside the unit.

If the carriage is stuck on the right side:
a. Check for any paper or object that may be restricting the carriage.
b. Move carriage all the way to the left side.
c. Check the paper path all the way to the right side and remove any paper still in the printer.

If the carriage is stuck on the left side:
d. Check for any paper or object that may be restricting the carriage.
e. Move carriage all the way to the right side.
f. Check the paper path all the way to the left side and remove any paper still in the printer.

If the carriage is stuck in the middle:
g. Check for any paper or object that may be restricting the carriage.
h. Move carriage all the way to the left side.
i. Check the paper path all the way to the right side and remove any paper still in the printer.
j. Move carriage all the way to the right side.
k. Check the paper path all the way to the left side and remove any paper still in the printer.
4. Remove the rear access door or duplexer (if installed) from the back of the printer.
5. Check for and remove any paper still in the printer.
6. Replace the rear access door, and close the top access door.
7. Reconnect only the power cable. If the printer does not automatically turn on, press the Power button.

NOTE: The printer may go through a warm-up period of up to two minutes. Lights may flash and the carriage may move. Wait until this warm-up period is complete before going to the next step.

8. If the Power light is on steady, print a self-test page as done in Step one.

If the Power light is not on steady and the carriage is still in a stalled position, proceed to the next step.

Step three: Plug the printer directly into a wall outlet

Verify that the printer is properly connected to a suitable power source by following the instructions below.
1. Verify that the computer and the printer have a three-prong power plug.
2. Remove the printer cable from any power strips or surge suppressors, and plug it directly into a grounded (three-prong) wall outlet.
3. Try the print job again to see if this step resolved the issue.

NOTE: If the printer prints when plugged directly into a wall outlet while disconnected from any power strips or surge suppressors, the power strip or surge suppressor may not be allowing sufficient voltage to reach the product.

4. If this did not resolve the issue, proceed to the next step.

Step four: Service the product

If you have completed all of the steps listed above and are still experiencing a problem, service your product.hope this helps

Flashing resume light also can mean:

1. cartridge is missing or an incorrect print cartridge is installed
2. cartridge is out of ink
3. dirty cartridge contacts
4. paper jammed

Check are cartridges firmly snapped into place and not empty. Use water to wash copper on cartridges if contacts are dirty.