Digitizer is not working, error code 20E0D (PIXEL VALUES AT PHOTOMULTIPLIER ARE TOO HIGH)

Hello colleagues, Our digitizer was working for eight years approximately, now is out of service, error 20E0D appears. we are located in Guayaquil, Ecuador. We suspect the problem is coming from the photomultiplier tube. Is there someone who can repair this digitizer in our city? My email is: mario_espinosa_guerra@hotmail.com Thanks for your help. Regards, Mario