The big scatter of data on the light curve of T CRB is identified with the flickering activity of the system. The data performed during April 1996 have a falling trend and they can be a part of a downward branch of a long-term and energetically powerful flare. Estimated energy 2 1035 J and the duration of this event were compared with the theoretical assumptions based on three typical physical scenarios, which can be the source of flickering. The dissipation of magnetic loops and the existence of the turbulent eddies are energetically deficient, but these scenarios are real in the case of less powerfull flares. The real explanation could be the instability of the secondary and variable mass transfer rate through the Lagrangian point, therefore through whole disc.