Brother MFC 990CW
The printer was printing perfectly until I had to replace all 4 ink cartridges and now it displays all inks are full but wont print shows 4F on screen. Can anyone help me please with a remedy.

Experienced technical support provide their insights in answering this question :
That’s a printhead error.

How to Identify and Fix Common printer Problems ?

Our sources include academic articles, blog posts, and personal essays from experienced technical support :

Remove all ink cartridges from the printer and gently clean the contacts on the printer and cartridges. Unplug your printer and leave for 10 – 20 minutes. Plug the printer back in and wait for the message to insert new cartridges. Replacing any that are almost empty, install all inks back in the printer.
It means that your device is not able to work up to its maximum potential. It is a common message that indicates that the print head of the Brother Printer is encountered with the temperature error or might have an internal electric issue.
Brother printer error

The Drum Error is another common error experienced by users of Brother printers. Both the error message “Drum Error” and “Clean Drum Unit” mean that the drum unit of your machine is dirty. The dirt may be caused by dust or by loose toner.

The Brother mfc printer is a multifunction device that can be used to print, copy, scan and fax. The device is compatible with both Mac and Windows operating systems.
During a print job, the printer stops feeding pages, an E4 error displays and the Resume light blinks. This indicates that paper might be jammed inside the printer. Note: Paper jams can be real or false.
According to the manual 4F means “DXE IPL is started“, but nothing else or more info to develop. Also the only beep codes the manual refers are an infinite loop of Long + a number of short beeps, not a single instance of 2 rounds of three long beeps.
Some of the most common printer problems that most of us have experienced include paper jamming, slow printing, uneven printing, and wrong colour output. If you use your printer frequently, we know how annoying it can be to have persisting problems with the printer.
An ADF (Automatic Document Feeder) is a great feature to have when used properly. It gives you the ability to feed several pages into a multifunction printer, scanner or copier, allowing you print print, copy or scan multiple pages at once without having to manually insert each piece of paper.
Multifunction devices usually have MFP (Multifunction Printer) or MFC (Multifunction Centre) ahead of their model numbers.

Relevant Questions and Answers :

the most relevant questions and answers related to your specific issue

4F displayed on Brother 990CW printer?
ANSWER : That’s a printhead error.

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ANSWER : What you’ll probably get is a computer virus from that shady site.

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ANSWER : Follow these instructions:

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ANSWER : I have a 2720DW from the netherlands it is a french model an it has the code 0009

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ANSWER : maybe you can download here Brother HL-2270dw Driver Download

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ANSWER : Since you don’t think it is important to give a model number, I suggest you Google your model followed by toner reset.

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ANSWER : Laser uses toner which is a powder that gets melted onto the page. Inkjet uses ink that gets squirted onto the page.

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PRINTER MX 320 CANON ALL IN ONE PRINTER
ANSWER : Probably a worn feed roller. You can try cleaning it with a damp rag as it might just be covered with paper dust.

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