power – My Raspberry Pi is making a high-pitch sound. What could be the problem?

My Raspberry Pi was unplugged without proper system shutdown during a stormy night. When I re-plugged it back into the power source, it makes a high-pitch sound. The Pi shows the red light flashing consistently, but the green light is flashing uncontrolably (a.k.a., it flashes many times per second). After some research, I found that my SD-card may be corrupted. I decided to re-format the SD card and reinstall the operating system. After doing so, the same problem persisted. I know that the flashing of green light usually indicates a problem within the boot sector of the Pi. However, the green light did not flash in such a paddern that conforms to any of the possible boot errors (e.g., a flash of three times may suggest that loader.bin cannot be found), thereby making it hard to troubleshoot the problem. What could be the problem of my Pi not booting up?

I have a Raspberry 4B.

Thanks for your time