Since everybody on this forum is mixing inside scope with virtual faders and knobs i guess this is a long shot

However. I have purchased an old Soundcraft Venue II and didt payed much. however when i came home and powered it up, the PFL/AFL light in master section is always on. However it seems like operational wise it will affect only the monitor output channel and headphone output (and the master led-meter), so its not like i cant use it.
Anyway is there any one here with some experience with similar problem? I have tried to use contact spray on all PFL and AFL buttons, and nothing changes. it seems like the problem are in the master section.. Any obvious or not so obvious things i can test out.
Rgs
Egil Hasting