peugeot 206 BRAIN PROBLEM

Hello friends, I have a
2004 model 1.4 HDI Peugeot 206. I am from Bursa.
While the vehicle was in motion, the engine fault lamp came on and all the needles on the indicator dropped to zero. Then I pulled over and checked the oil and there is no problem.
When I turn the ignition on and off; The engine malfunction, handbrake and battery lamps kept flashing and all electronic components of the vehicle such as headlight, radio, air conditioner, wiper, screen do not work. There is no problem with the operation of the vehicle. I took it to the electrician and the values of the battery and charge were normal. When I took it to the brain therapist, BSI said that the brain had flooded, and even this car had undergone such a procedure before that the immobilizer was cancelled. He said that he would go for the way of repairing the brain, or if it didn't, there would be a change with the brain. Has anyone had this type of brain problem before?

Hello teacher.

I just found the master, I'm not sure, as a result of the research, it looks like I will have BSI intervene after I have a good electrician check all the fuses again.