Sent faxes have the right side cut off and black

Sounds like the scanner section (the glass **** part in the original scan section). These are notorious for going out and sending partial black or all black pages. Try making a copy and see what it looks like, but if it's sharp lines on (across) sections of the copies, then that's what it is. It's about a $40 part and easy to change. Just lift the "tab" on the holders right side....slide the unit to the right...lift up the left section...pull it out and unplug it. Be carefull not to let the connector fall into the slot it came from or you'll have to disassemble it further or fish it out. Replace in opposite directions.