JVC BR-S822DXU VHS/S-VHS playback VCR "dnr" Questions

no colour at playback when tbe switch is on i have jvc br-s822e pal with tbc and dnr boards installed , when i playback and switch the tbc to on it becomes black and white playback while that if you ...

...and allign the internal switches of tbc boards in br-s822 i have the br-s822e with all tbc and dnr boards installed any idea about the internal switches inside the tbc boards and the video lum. ...