20 Most Recent Brother MFC-7340 All-In-One Laser Printer - Page 2 Questions & Answers

copy on my machine then i tray to copy

Are you trying to print from the main paper tray with the envelope or from the auxiliary single page feeder? The auxiliary insert should be directly under the "Brother" logo on the front of the printer. Insert the envelope there. If it's a standard light weight envelope and it gets stuck still then I'd suggest there is a paper jam somewhere or possibly the fuser is going bad.

Printers are particular about which usb port they are plugged into, a virtual printer port is assigned to USB1 in the computer, when you select the printer port for it to use. You may need to plug the printer into each USB port, until you fine the USB port 1 which it works in, remember to always connect it to this same usb port, otherwise it will not work. There is only one USB port number 1.

most probably the quality of the telephone line is poor and the ECM (error Correction Mode) is automatically activate and stops the transmission

Is it an OEM cartridge or a refill? Once you changed the cartridge, did you reset the counter? What error code is it reporting? All of these items have to be considered. The biggies are if it's an OEM or not, and the exact error code it's displaying.

go to menu setting scroll down to quality and that should show you from there...high is dark

Try cleaning the drum. I normally use 99.9% pure isopropyl alcohol, however, a soft tissue might do the job. You might have to replace the drum of the cleaning does not help especially if there are shinning spots on the drum.

actually, you dont' really need to replace your drum, your drum actually is good for 5-6 years.
you just need to clean up the drum with duster and put that back into the machine.
when reset the drum, you just need to open the front cover and press Clear buttom then 1.
after that the whole thing will be reset and ready to go for it.

Have you gone into control panel and selected administrative tools and then services. Scroll down to print spooler and disable and then re-enable it and see if that helps. Also check to make sure that the printer is compatible with your version of windows. May have to update your drivers. I have a MFC-7220 myself.