Newest Yealink Firmware

Problematic Firmware Issues

Yealink T4s

Yealink T5's

 

 

Problem Firmware that you can not upgrade/downgrade from on T-Series (3CX locked rom)

Problem Firmware that has issues with Device config or usage

  • X.85.X.X - Transfer issues - upgrade or downgrade away from 85 firmware
  • X.82.x.x or x.83.x.x - Both have issues with updating config and will need to be upgraded to atleast x.84.x.90 (T4) or .95 (T5)