Will not print F4
In able to print F4
All-in-one inkjet printer, copier, fax and scanner with wireless home or office advantages.
The following links give info regarding Brother Error codes, 1st link is for your printer, 2nd is more general.
Neither one mentions your specific error code, but hopefully may be of some help.
(there are 5 pages to view all codes, just click on the right arrow symbol under the model selection box in right side of page)
Here is the Brother contact page they may be further able to assist you
Past 24 Hours: 1
Past 7 Days: 2
Past 30 Days: 4