Hi sir:
However i recommend you to Reset the Cpu or Microntroller in the Main Board.
Attached is there my schematic diagrams, for to do it Reset +Example of 8085 CPU , see carefully, and search in Google according with his CPU or Microcontroler that main board has, the Pins schematic, in order to carry the RESET, but
1) you must measure the Power supply or Vcc for CPU or Microcontroller
2) Clock of Cpu or Microcontroller, any of those if there are out or faulty, the Cpu or Microcontroller Will NOT the Press with All this errors Showing in the Screen.
3) Please do Not be afraid, with this Test, You will loose any information from his machine, only you will test 2 things with this steps.
4) a) If the power supply +Clock x CPU or CPU= is Defective b) or The Software or Programs or Firmware is Corrupted!!
Blessing