SM74-4

hi dear elder, I have the screen of my sm74 that does not light. I'm looking for but I can not find someone could help thank you very much

 

Open back side cover
Check supply is coming or not.
You can also fix external monitor to run the machine temporary

 

when I put the machine in the led being on the card of the screen flashes.

 

Sir
There is problem bin blast invertor(which give supply to the tubes for illumination.
To confirm the Flash light using external source from side and see r able to see the display pix