Late 2015 5K iMac made crackling noises, no longer boots

About a week ago my Late 2015 5K iMac started making crackling noises that generally seemed to come from the lower left side of the display. The sound was similar to bacon cooking or rattling cellophane. The sound was constantly present whenever the iMac was awake but it would fade out after a few seconds when shutting down or going to sleep. It also seemed to get slightly louder when the iMac was using more power (for instance, when gaming) and would get slightly quieter when the system was idle and the display was dimmed.

(At first the noise sounded like a clicking hard drive but I have not experienced any storage related issues. It also seemed to be distinct from the sound of the hard drive.)

Today I shut down the computer and unplugged it in an attempt to reset the SMC. When I plugged it back in and attempted to power it back on there was no response. No chime, no fans kicking in, no response from pressing the power button whatsoever.

From what I’ve gathered this sounds like an issue with the power supply to me. Does that sound accurate? Do you think that replacing the power supply might solve this issue, or is there something else that I should be concerned about?

Thank you.