I have a Dell Inspiron 3656 and been having it for over a year. It didn’t have problems until recently.
Every time I’ve tried to power it on, the computer doesn’t actually connect to the monitor. I know my monitors are working since the two display a “no signal” on their screen. The power button on the PC is a solid white, I checked the power supply diagnostic system and it displayed a green light. The computer, when turned on, does not show a red LED like it’s supposed to in front of the case. I’ve also noticed that it doesn’t go into sleep mode.
The problem isn’t the power supply and it’s not the monitors.