An error #704 message keeps coming up and telling me to check supply, but as far as i can tell everything is loaded correctly. any ideas?

It is possible that your Epson WF-7820 is experiencing a paper jam or a misalignment of the paper cassette. If the paper cassette is not correctly inserted into the printer, the printer will display an error message that tells you to insert the cassette correctly. To resolve this issue, make sure the paper cassette is correctly inserted and that any paper jams are cleared. If the issue persists, try resetting the printer by unplugging it and then plugging it back in. If the error message still appears, contact Epson support for further assistance.
Loading Paper in Cassette 1 (Upper Cassette)
https://files.support.epson.com/docid/cpd3/cpd39348/Source/Printers/Source/Paper_Loading/Tasks/XP800/loading_paper_upper_xp800.htmlfaq-207896 ' SPT_C11CB58201 ' Epson WorkForce WF-7520 ...
https://epson.com/faq/SPT_C11CB58201~faq-207896?faq_cat=faq-topFaqsWF-3820 Series User's Guide
https://files.support.epson.com/docid/cpd5/cpd58812.pdf

He's got the same problem with the Polar 78ES.
Error code 704

Yes, the black cartridge could very well be the issue. In fact, I think it's likely.

704 is a supply error. You get a 704 either because the supply sensor is broken or is out of calibration, or because you have your supply type on the printer set for something different than what you're printing on.
If the rubber platen roller that turns and feeds your supplies through your printer is too slick, or has a roller wrapped around it - that can cause a 704 error too.

If you have a black line on the back of your supplies you should be set for "black mark". If you have labels that have a space between them, you should be set for "die cut".

Check to see that you have the correct supply selected under "supply type". Are you running black mark supplies or die cut supplies? If the supply type selected doesn't match your actual supply type, you'll get a 704 error. It's also possible that the black supply sensor could be broken, or your platen roller (large black roller) needs to be cleaned. Clean it with alcohol.

This problem is due to your `SP2'. Please download and use a browser like Firefox which is not tightly integrated with the operating system and your shall bypass this problem.

E 90 is an error code regarding the main pc board connection.

the solution is to secure all connection to and from the main board.
tighten the sockets and make sure they are not loose that could create a problem while vibrating and shaking.

tnx 4 using fixya,

drcool

Hi Mate;

Just had the exact same problem with the spin cylec and now its stopped completely, I was getting ERR 7 on the display, its telling you that there is something wrong with the motor.checked the motor and found that one of the Carbon Brushes was sticking/Stuck, Just 2 phillips head screws and the carbon brush is out, mine had a bit of melted plastic/casing snagging the Carbon brush, i just jusd a bit of fine sand paper to clean the Brush, put it all back together and lo and behold everyting works.
Hope this helps

Listed below are all the error codes:

Display messages:
Err1: Error message. Door is not properly shut 20s after program is started.
Correction: Shut the door properly.
Err2: Error message. Drainage error, water not emptied within 4 min.
Correction: Clean the filter and check the drain hose for blockage. If error still exists, please contact the maintenance personnel.
Err3: Error message. Temperature sensor is not properly connected or damaged (display at the end of a program).
Correction: Contact the maintenance personnel.
Err4: Error message. The heater may be broken or the desired temperature is not met within the specified time due to an overloaded laundry (display at the end of a program).
Correction: Reduce the load and restart, or contact the maintenance personnel.
Err5: Error message. The required water level is not reached within 10 min, or the water level exceeds the protection value.
Correction: Check to see if the tap is turned on and the water pressure is correct. If error still exists, contact the maintenance personnel.
Err6: Error message. Motor speed error. It may be not properly connected or damaged.
Correction: Contact the maintenance personnel.
Err7: Error message. Motor overheat protection or is damaged.
Correction: Contact the maintenance personnel.
Err8: Error message. Water level exceeds protection value.
Correction: Contact the maintenance personnel.

Regards

Bull

704 on this printer means
Printer has not sensed a supply mark within the specified number of inches.
Since this is a black mark printer, there should be black squares at the bottom of the liner that passes through the printer. If you have no black squares, then you're using the wrong supplies.

The plastic that holds the supplies in place should spring open if this is a 6032 or 6037. Some of the 6032 and 6037 printers have a supply lock that is a little gray tab at the base of the cavity where the supplies are held in place, but before they angle up past the supply sensor and over the rubbery roller. It is possible that this is locked in the wrong width for your supply size. If it is, try folding it out away from the supply roll so that the supply holder can move freely, judge the width of your supplies and use one of the 3 fixed positions for locking the supply holder in place. Your supplies should fit snugly either way.

If your supplies are loaded correctly, go into diagnostics and go through the paper registration to try and calibrate your supplies. If the printer passes, you should be good to go. If it fails, call the support line from monarch.com, and a repair tech can walk you through the proper setup by having a quick 5 minute call.

Good luck.

HI
RESET TO FACTORY SETTINGS AND TRY AGAIN.