PS4 Slim no lights + 3 long beeps when power button is pressed

Took apart a PS4 slim to replace the HDMI port. After the new port was installed, I put the console back together. As soon as the power cable is plugged in, the console beeps 3 times. The beep pattern sounds similar to how a PS4 beeps when it overheats. When the power button is pressed, there are no lights and it just beeps 3 times after a couple of seconds. I tried a different, known good power supply as well as re-seating the power supply. What could the issue be?