While it isn't a tech support forum, there's still a bunch of experienced enthusiasts here, I think. And asking for help will get you more info than just trying to do it yourself
Generally this doesn't immediately look to me like a PSU failure, but I have a feeling that a poorly functioning PSU might be causing the motherboard to misbehave anyway.
Your best bet would be to firstly try disconnecting everything that isn't necessary for the computer to work, including peripherals, internal drives, maybe even your GPU if your motherboard has some integrated graphics. Just leave it with a monitor, keyboard and the bare minimum inside required to work, and try launching it again.
If this doesn't work, it would be a good moment to try and boot the computer with a different, verified power supply.
If the system won't boot with a properly working power supply, and the original power supply works with a different PC, it's possible that your motherboard died, and it might have taken out most of components connected to it, and this opens up a whole new proccess of checking if parts work properly.
Oh, also maybe check if there's power in the outlet you're plugging your PC into. A damaged PSU might have tripped a breaker.
Also, it would be very useful if you posted your system specifications. Most important would be the manufacturers and model numbers of your PSU, motherboard, CPU and GPU. If you connected any atypical devices to your computer, it would be useful to know too.