You can make printers firmware downgrade by Yourself now.
Download WIC utility and see video tutorial:
How to downgrade printers firmware? Video tutorial.
October 29th, 2014 
John 
Posted in Video Tutorials 
October 29th, 2014 John Posted in Video Tutorials Language
WIC News- Added support for WF-2110/WF-7310/WF-7840. 10/26/2023
- Added service functions for some printers. 08/16/2023
- Added recovery mode firmware. 07/24/2023
- Addedd support for M15180/M15188/ET-M16680/WF-M1138. 06/11/2023
- Added support for TS700 и GM2040. 05/07/2023
- Fixed specifications for XP-720.
- Added support for K105/205/305. 04/15/2023
- Added support for M1140 M1170 M1180 M2140 M2170 M2180 M3140 M3170 M3180 Series. 02/23/2023
- Added support for L14150 ET-15000 EW-M5610FT Series. 02/22/2023
- Added support for L8050 L18050 ET-18100 Series. 02/21/2023
