Fax copies come in too light to read

The message "Ribbon Empty- Reset or Replace" will appear on the display of your Brother machine when your ribbon cartridge has run out and needs to be replaced.
Goto this link and have a read up.
https://support.brother.com/g/b/faqend.aspx?c=gb&lang=en&prod=faxt104_eu&faqid=faq00000545_001

ok..let's start with this step

go here, get a fresh set of drivers, and remove old s/w, then install the new set

Replacing the Print Cartridge
1 Open the front cover, and then open the top cover by pressing the blue levers on both sides of the top cover.
2 Remove the old print cartridge containing the used ribbon and dispose of it.
3 Remove the plastic stopper from the new print cartridge.
Note You can reuse the print cartridge until it breaks. If you purchased refill ribbons, follow the instructions that came with them.
4 Turn the black spool on the right clockwise to tighten the ribbon as shown.
5 Install the new print cartridge by inserting the recessed first, and then placing
the cartridge into its four holders.
6 Press down on both sides of the top cover to close it securely.
7 Close the front cover.
Brother Customer Service at 1-800-284-4329 (in USA) or 1-877-BROTHER (in Canada).
Vertical Black Lines When Receiving
The sender's scanner may be dirty. Ask the sender to make a copy to see if the
problem is with the sending machine. Try receiving from another fax machine.
If the problem continues, call Brother Customer Service at 1-800-284-4329
(in USA) or 1-877-BROTHER (in Canada).
You can save money by purchasing the 2-PK Refill Ribbon Rolls (PC302RF).
Installation instructions will be included. If you handle the print cartridge (frame)
carefully, you can reuse it until it breaks.

Look on pages 12-9 thru 12-11 in this link to Brother for your Fax 575 for ribbon / cartridge installation instructions.
http://www.brother-usa.com/ModelDocuments/Consumer/Users%20Manual/UM_FAX_575_EN_75.PDF

you need to replace the cartridge or I rewind my cartridge. sane cartridge for 3 years.

Have you tried replacing the ribbon cartridge? If that doesn't resolve the problem, then there is a fault with the thermal imaging head. You did say both Recieved faxes and copies, correct? If faxes you send out are clear, then the above mentioned would be correct. Let me know, please.

If it is a real genuine Brother toner. Not a reman. You may also need to change the drum. If you have a user manual, it will show you where the drum life setting is in the menu structure. Make sure the little glass window inside on the right is clean so it can read the toner level. Make sure the toner save feature is turned off.

I’m happy to help further over the phone at https://www.6ya.com/expert/jayw_0e86fb055a7b73de

you will probably have to have all cartridges working.

Winding technique:
To wind a new ribbon, take the cartridge housing apart and remove the old ribbon and two cardboard cores. The new ribbon is fitted with the larger roll (the ink ribbon supply spool) at the rear side of the cartridge (as the housing is viewed when it is normally installed into the machine). The ribbon winds over the topside of the rear spool (the supply side) and feeds into the underside of the front spool (the take-up side). Make sure the ribbon is wound neatly, evenly and is tight. If the ink film has become detached or is too loose on the front spool it will not wind on and cause a machine error. If required, use a small amount of sticky tape to secure the ink film to the front cardboard spool and then neatly wind it on to the take-up spool a minimum of five turns, making sure the film does not overhang at the edges. Now reassemble the housing and refit into the machine.
If it’s still not fixed:
If problems persist after fitting a new ribbon, try replacing the entire ink ribbon unit (cartridge housing + a new ink ribbon) using a new, genuine Brother unit before requesting a service; this will be less expensive as the actual housing may have been damaged and is causing the problem and this unit is readily available as a consumable item through sales outlets. If the machine still has problems, book your machine in to be repaired with an authorised Brother Service Centre.

How is the copy when you try to just make a copy of something? If it copies good, then it might be the senders machine.
If when you make a copy, and the copy is blurred, then it is probably your ribbon/ink cartridge.

If it is the cartridge, just replace the cartridge, and you should be good to go.
Hope this solves your problem.
Good luck.
Mac =)