Optiplex 740 Blinking 3 and 4

[Bruh171717]

My Optiplex 740 is Blinking 3 and 4 and it won't turn on. How do I fix this?

 

[Darren]

Please stick to one thread per question.

https://www.computerforum.com/threads/optiplex-740-blinking-3-and-4.241867/