Paper roll

Peel the beginning edge of the paper roll off of the rest of the roll. It will be lightly glued to the roll to keep it from unwinding.
Cut the end piece of the paper if it tears when you pull it off of the roll. You want the edge to be the same level all the way across so that it will feed into the machine easily.
Flip the paper holder bar away from the Unisonic adding machine and slide the paper roll onto the bar. You want the paper on the roll in a certain position. Make sure that when the loose edge of the roll is on the bottom, that it is facing in the direction of the machine so that you will be able to pull it toward the machine to feed it in.
Pull the lever up that is located near the paper slot in the back of the adding machine.
Take hold of the edge of the paper and feed it into the paper slot.
Put your finger on the paper roll-up knob and spin the knob toward the back of the machine. This will turn the rollers inside the machine and push the paper up. Stop turning when you see the paper come through and above the cutter.

Turn off the Sharp EL-1801V.

2 Cut the end of the replacement paper roll for a fresh edge and to ensure a smooth feed. Do not tear the paper roll, as feeding a torn paper roll can cause a paper jam.

3 Insert the cut edge into the paper opening on the back of the Sharp EL-1801V. Hold the paper roll so that the edge being fed into the machine is coming from the bottom of the roll. Turn the power on.

4 Press the "Feed" button until the paper is fed through the unit. Lift the metal paper roll holder up. Slide the paper roll onto the paper-roll holder.

Read more: Directions for Replacing the Paper Roll on a Sharp EL-1801V ' eHow.com http://www.ehow.com/how_7294657_directions-paper-roll-sharp-el_1801v.html#ixzz1eNqkJA8g

A fix from a forum:

Procedure 1 We found this procedure to work for the Stylus Photo 1270 type printer, and understand that it also works for the 870 range and even earlier models like the Stylus Color 740. The error is indicated on these printers by all four lights on the printer flashing. Even if you press the power switch on the printer, the lights continue to flash, and the printer does not turn off!

1. Turn off your printer, ensuring that the print head is at it's home location and locked in place as normal;
2. Power off the printer at the wall or by removing the power cable, for at least 20 seconds;
3. When you restore power to the printer at the wall socket or by reinserting the cable, if the lights come back on straight away, the printer's power switch was 'on' - switch it off and return to step 1;
4. Hold down the paper-feed button and the button with the ink-drops next to it, and then turn on the printer, still holding the buttons down;
5. When the paper-out LED flashes, release the buttons;
6. Press and hold the Cleaning button, until several lights flash - this will take a few seconds (i.e. then release the button);
7. The printer will now attempt to reset, including resetting the EEPROM memory and running a short (about 10 seconds) cleaning cycle.

Procedure 2

1. Turn off your printer, ensuring that the print head is at it's home location and locked in place as normal;
2. Hold down the paper feed button only;
3. Turn on the printer;
4. As the paper feed light starts flashing, release the button;
5. Immediately hold down the ink-drops button for some 10-20 seconds or until the printer springs into life;
6. Allow printer to complete it's processing, then turn off for a few seconds, and back on again for a newly working printer!

Procedure 3 - for 1290 and possibly 890 printers 1290 printer with green (power / data) and red (ink / paper feed) lights flashing alternately:

1. Switch off printer with panel switch;
2. Switch off printer at mains switch - leave off for 20+ seconds;
3. Hold down roll feed and sheet feed buttons;
4. Switch on at mains;
5. Switch on at printer panel;
6. Continue to hold down roll and sheet feed buttons until both green and red lights flash together in synchronisation, not alternately;
7. Switch printer off and then, after a few seconds, on again at mains switch;
8. When red and green lights are both flashing in synchronisation, release the roll and sheet feed buttons;
9. Press and hold down the ROLL FEED button (the one at the extreme left) and keep it down until the machine finishes whirring, cleaning etc and the green light comes on steady;
10. Release the roll feed button and all should be well.

Replacing the paper roll involves feeding the evenly cut, uniform end of the roll through the fine slot located under the paper arm at the back of the calculator. (Even if the paper is only slightly wrinkled or cut unevenly, it will not feed through the teeth in the loading area.) 
When getting ready to feed the paper into the calculator, envision your printout feeding out of the machine away from you and back toward the paper roll. Don't insert it upside down.
To get the paper feeding through once you have partially fed it into the teeth, gently tap the paper feed button. Once or twice should do it. (The button is located on the far top left of the control panel, indicated by an arrow jagged saw mark icon). 
Then, slide the paper roll onto the feeder arm and you're in business.

On inside of machine it states how to:
1. Place new paper roll on the left hub while pushing it in, lowering the roll into the compartment making sure it is inserted onto the right hub.
2. Pass the leading edge of the paper through the paper cutter guide and the cutter.
3. Remove any slack in the paper.
4. Close the cover. The paper will feed out automatically.

The paper rolls over top front to back.

This machine problem can be very involved.
A paper jam as described can be in any locations of the copier.
First of all when the toner-developer falls on the base of the paper feeder, it can contanimate all paper feed shafts and even sensors, and plug connections.
Worn feed rolls can cause the machine to jam. Clean the rollers and see if it corrects the problem.
A bent paper tray can cause the copy to skew, causing jams.
Sometimes the plasic paper path baffles are warped leaving narrow gaps in the paper feed path not allowing the paper to go through properly.
A bad paper feed sensor can cause inttermittant paper feed jams. This sensor is located just above the feed rolls. A involved process to take out without breaking the plastic components.
The machine has paper feed clutches located at the back of the feed rolls. To get to them it is also involved. Sometimes these clutches slip and will cause paper feed problems. There paper feed solinoids may operate intermittantly not allowing the paper feed clutch to operate correctly.
The main board can also cause these types of problems, not allowing the correct signal to operate the paper feed solinoids.
There is so much in this area to locate and isolate for paper feed problems.
If all else fails, call Xerox for a service repair.

clean rollers

first the paper is rolled over the top and then roll it slowly under untill you can pull it out by hand. At this point you can close it and it will automatically start to feed.

That is an exit Jam code in the fuser.
You may just have one of the fingers bent straight down blocking the paper.
There also may be a secondary code that is causing the E-4-0.
But that is where to start. Look under the exit web cover for a piece of paper crumpled in that area.
Once there you may have to remove the fiser web cover to remove that jam and straighten out the finger.
MAKE SURE IF YOU GO INTO THAT AREA TO UNPLUG THE MACHINE.

The cam that keep the pressure between the roller pick up and the lower feed is the solution