I do not know who to operate the scanner function on my Brother MFC-8500

Directly from the Brother web site.
https://support.brother.com/g/b/downloadtop.aspx?c=us_ot&lang=en&prod=mfc8500_us

This link has all the guides and manuals for your printer...free. The basic and advanced guides explain the error and also have a section on how to reset the machine.
Manuals MFC J6910DW United States Brother

Here is a post from the FixYa site from 2 years ago explaining your problem. It seems to be a problem with the IP address.

http://www.fixya.com/support/t678281-brother_mfc_9449cn_cc3_205_03031f04

use the link below to download the manual http://www.retrevo.com/search/v2/jsp/downloadPage.jsp?doc=c89f9d733cfd63f488f29fa28444b839&modelid=260209&q=Brother+MFC-8500
A printer driver is a piece of software that comes with the printer so that the operating systems knows how to communicate with the printer and do the settings so that it works the best.

Polygon motor does not synchronize with the reference clock

With my Brother 8840D I have had paper jams that when cleared would not delete from the display nor would the machine operate until I unplugged the machine for around eight hours. I guess it is a sort of reset or reboot.

hi,

please log on this site for complete details for your Operation instruction.

http://www.brother-usa.com/ModelDocuments/Consumer/Software%20Users%20Manual/SUM_DCP_110C_MFC_210C_3240C_3340CN_420CN_5440CN_5840CN_620CN_EN_1266.PDF

Check to make sure that the PC Fax Function is turned off. I noticed after I connected the 8500 to my PC and installed the software, I too could no longer receive faxes and it was corrected after I turned this PC Fax function off.

The function is located by:

1. Press the MENU button.
2. Select Option 2.
3. Select Option 1.
4. Select Option 8 (PC Fax) and turn that function OFF.

Hope this helps!

Have you tried a new toner and drum unit? if not please do so. If that doesn't work then it is a scanner lamp failure and will need replacing.

You can fix it but trying to obtain this part for such an old machine will be hard. Don't know the part number sorry.

Thanks J

If there is noise on phone line machine reduces speed to enable fax to be sent. Have line check or try machine on different phone line to ensure it is a phone line problem.