Carriage jam ,opening door and check seems ok close door and press ok and same problem occurs

Check the side sensor board or the head sensor

Ok guys I was struggling with the same issue for HP 3520, so I opened the cartridge access door and press down on a small black piece of plastic (that holds the carriage in place) once you press it there will be a slight click sound and thenn move the carriage to the right hand side.
Now close the lead and click ok the clear message.

You should be ok.

This method worked for my model.
You must have the power turned on otherwise it won't move.

To resolve the issue, you can try each solution in this document in the order presented.MPORTANT : Each time you try a solution, try to print a self-test report to determine if the hardware functions correctly. To print a self-test report, use the steps in the following table:Load plain white paper into the input tray.Press Setup on the product control panel.Press the right arrow ( ) to select Print Report , and then press OK .Press the right arrow ( ) to select Self-Test Report , and then press OK . The self-test report prints.Solution one: Turn the product off and on again Follow these steps to turn the product off and then on again to reset the printing mechanism Press the Power button to turn off the product. If the product does not turn off, continue to the next solution.Wait 60 seconds.Press the Power button to turn on the product NOTE:The product might go through a warm-up period. The product lights might flash and the carriage might move. Wait until the warm-up period finishes before you proceed. Try to print a self-test report. See the steps on how to print a self-test report at the beginning of this document.If these steps resolved the issue , and the self-test report prints , there is no need to continue troubleshooting. If the issue persists , continue with the next solution. If the self-test report does not print , continue with the next solution.Solution two: Clear any paper jam Follow these steps to clear any paper jam.Step two: Clear the jam from the rear of the product Use one of the following methods to clear the paper jam from the rear of the product. If your product has a two-sided printing accessory (duplexer), skip to Method two.Method one: Clear the jam from the rear access door Press the Power button ( ) to turn off the product, if it is not already off.Disconnect the USB cable from the rear of the product.Disconnect the power cord from the rear of the product.Remove the rear access door: Press the tab on the left side of the door inward, and then pull the door out.Figure 1: Remove the rear access door ently remove any jammed paper from the rollers.CAUTION:If the paper tears while you remove it from the rollers, check the rollers and wheels for torn pieces of paper that might remain inside the product. If any torn pieces of paper remain inside the product, more paper jams are likely to occur.Figure 2: Remove torn pieces of paper from the rollers Reattach the rear access door. Gently push the door forward until it snaps into place.Method two: Clear the jam from the two-sided printing accessory (duplexer) Press the Power button ( ) to turn off the product Disconnect the USB cable from the rear of the product.Disconnect the power cord from the rear of the product.Remove the two-sided printing accessory (duplexer) from the rear of the product: Press the buttons on each side of the duplexer, and then pull it toward you. Figure 3: Remove the two-sided printing accessory Gently pull the jammed paper out of the rollers.CAUTION:If the paper tears while you remove it from the rollers, check the rollers and wheels for torn pieces of paper that might remain inside the product. If any torn pieces of paper remain inside the product, more paper jams are likely to occur.Figure 4: Remove torn pieces of paper from the rollersIf you do not see jammed paper in the rear access area, push the latch on the top of the duplexer, and then lower its cover.Figure 5: Open the duplexer - Latch on top of the duplexer Duplexer cover Remove any jammed paper from inside the duplexer.Close the duplexer cover, and then reinsert the duplexer into the rear access area of the product. Figure 6: Reinsert the duplexer Push the duplexer inward until it clicks into place.Step three: Clear the jam from the front of the product If you cannot remove the paper jam from the rear of the product, follow these steps to remove the paper jam from the front.Open the cartridge access door.Figure 7: Open the cartridge access door NOTE:The carriage should be on the right side of the product, out of view. If it is on the left side, close the cartridge access door, and then turn on the product. Unplug the power cord from the wall outlet, and then open the cartridge access door again.Look for any pieces of paper or other debris inside the cartridge access area.Gently pull the paper out of the rollers.CAUTION:Remove paper from the front of the product as carefully as possible. If any torn pieces of paper remain inside the product, more paper jams are likely to occur, and this could damage the print mechanism.Close the cartridge access door.Figure 8: Close the cartridge access door Reconnect the USB cable to the rear of the product.Reconnect the power cord to the rear of the product.plug the power cord back into the electrical outlet. Press the Power button ( ) to turn on the product. Reload paper in the input tray.try to print a self-test report. See the steps on how to print a self-test report at the beginning of this document.If these steps resolved the issue , and the self-test report prints , there is no need to continue troubleshooting.If the issue persists , continue with the next solution.If the self-test report does not print , continue with the next solution.Solution three: Make sure the carriage moves freely Use the following steps to make sure the carriage moves freely.Press the Power button ( ) to turn on the product, if it is not already on.Open the artridge access door.Figure 9: Open the cartridge access door Without turning off the product, disconnect the power cord from the rear of the product.WARNING:You must disconnect the power cord to move parts by hand without the risk of an electrical shock.unplug the power cord from the wall outlet.Look inside the product to see where the carriage is stuck, and then check for any torn paper or other objects that might restrict the movement of the carriage.NOTE:You might need a flashlight to illuminate areas inside the product Figure 10: Use a flashlight to see inside the product Remove any loose paper or obstructions you find.Figure 11: Example of obstruction in carriage access area Reach inside the product through the cartridge access door, and then manually move the carriage. You might have to reach through the paper output tray to access the carriage.If the carriage is stuck on the right side of the product , move the carriage to the left side of the product.If the carriage is stuck on the left side of the product , move the carriage to the right side of the product.Make sure the carriage moves freely across the width of the product by gently pushing the carriage to the left, and then to the right.Close the cartridge access door.Figure 12: Close the cartridge access door. Reconnect the power cord to the rear of the product.Plug the power cord into the wall outlet. Press the Power button ( ) to turn on the product. Try to print a self-test report. See the steps on how to print a self-test report at the beginning of this document.If these steps resolved the issue , and the self-test report prints , there is no need to continue troubleshooting. If the issue persists , continue with the next solution. If the self-test report does not print , continue with the next solution. four: Remove and reinstall the cartridges Improper placement or installation of the cartridges can cause the product to indicate a carriage jam error.

Try checking the paper trays, open all the doors and close them.

This error message is displayed by the printer when paper is jammed in one or more locations. In such a case, users are recommended to remove the jammed paper from the specified location. The entire paper path must be checked for any pieces of paper. To stop the message, open and close the top most cover of the printer. Lastly, verify the flags and the sensors. If the problem persists, the cause of the error message could be a broken sensor or sensor lever.

Have you tried moving the carriage to see if it really is jammed? Maybe you haven't put the levers down properly on your new cartridges....remove them, see if the carriage slides, then refit them and check the carriage again. You wont visually 'see' a carriage jam,; you have to try moving it. By the way, if it doesn't move, DONT force it to try and overcome the jam try and reason out why it doesn't move.
Hope this helps!
nicam49

If paper is jammed, a Paper jam message will appear on the control panel display.

Follow these steps to clear the jam:

1. Gently pull any jammed paper out of the output tray or sheet feeder.
   
   
2. If the paper is stuck inside, turn off the Epson Stylus CX.
   
   
3. Open the scanner, remove the jammed paper and torn pieces, close the scanner, and turn the Epson Stylus CX back on.
   
   Note: Be sure to check the far left of the carriage area when checking for jammed paper. Paper that is jammed there may be hidden from view.

If paper jams inside the Automatic Document Feeder, clear the jam as follows:

1. Open the Automatic Document Feeder cover and remove any jammed paper.
   
   
   
   
2. If necessary, lift the document cover and remove any paper that has jammed inside.
   
   
   
   
3. Press OK to clear any messages on the display screen.

I think the message is instructions, as in
(1) open door (2) clear carriage jam (3) press enter
So there is something internal to the printer that makes it think it has a carriage jam, piece of paper under a sensor, dirty or stuck sensor.
If you can't find it using a bright light, try canned air.

The Jam error is most likely cause by one or more of the sensor flags these are the plastic usually black things hanging along the paper path. One of those are either stuck or broken. Check the path and look for those items.

your printer needs servicing. plz take it to some professional