2 black running marks on length 0f sent fax, in middle of page.

It sounds to me like you have a bad or worn out ribbon roll..check it and see if there are any creases

Is it when u send or recieve faxes!If on sending(open the part where u put in the faxes to sent!U will see a big black roller and under that a small black one,undeer that a long strip of glass,make sure that there's no marks of any kind on the glass!If recieving it might be on the fax that is sending the fax!Good Luck!

Most likely a fax has been sent or a page copied with 'white out' (Liquid Paper), still wet on the page. As the page feeds over the scanner, (a narrow strip of glass that runs across the width of the page along the feed path) the wet liquid paper comes off on the glass as a thin line and dries. Thereafter, when copying, scanning or sending a fax, the scanner light does not go through the liquid paper streak and the result when printed is a thin vertical line that runs the full length of the page.

If this is your problem: follow the path that the paper travels when sending a fax or making a copy, until you find the scanner (narrow glass strip). Take a clean, soft cloth and a small amount of methylated spirit (or white spirit) and remove the now dried Liquid Paper from the glass. Clean the whole strip ensuring that the glass is left clean and dry.

If you can copy the document, then you can send it BUT the receiving fax will probably have restricted length fax pages to prevent jammed documents at the sending end causing the receiver to use all the paper. If you have access to a service manual you can restrict the length of faxes sent and received on your machine. But it may be the receiver with the restriction.

Try making a copy of something or printing a transmission report or journal from the "reports" menu. If the same problem is apparent on these printouts, then your drum unit or toner cartridge need to be replaced

lift the auto feeder and clean the scanner glass that your pages scan across -it is dirty. You can make a copy afterward and this will tell you if you have solved the problem.

either you neede a new drum or this is problem in the fuser section. may be baf heater roller. try cleaning the grid on the drum cartridge with a soft bristel pauint brush good luck brother sr tech

change your resolution from fine to super fine and make a copy to verify your fax machine"s scanner operation.

If WHITE LINE(S) appears clean the scanning unit...if BLACK LINE(S) clean the thermal unit.

I've seen this before. Since the printer portion is working fine that points to the scanner mechanism as the culprit. There are two things I have seen cause this. 1) If the line is a perfect rectangle all the way to the edge of the page then the light bar itself is dying and there isn't much you can do to save the unit. Send it in for warranty repair if you have the option. 2) If the line is more like a skid mark like you mentioned, then the paper that is being scanned is not pressing up fully against the light bar. Not enough light is bouncing off the page and the scanner can't read it well. This can also be caused by a roller not feeding correctly and then bunching up the paper a little bit. I would check the rollers for wear or something being off center. This can sometimes be caused if the machine has ran a high volume or thick paper. I would really think the cause would be one of these two since you are getting the marks at odd intervals, if the intervals were regular it could *possibly* be the drum but as I stated before, with the print function working right, I doubt it.