I'm using a Lancool II Mesh Performance case with the front USB-C attachment. While my phone was charging from the PC, it touched the connected headphone jack and the computer immediately froze. After restarting, the power supply turns on for a few seconds, shuts off, and then repeats the cycle. The system never reaches the BIOS. Is the motherboard or another component permanently damaged, or is there a way to troubleshoot this?
2 Answers
First, unplug the PC from the wall. Remove the motherboard’s CMOS battery, then hold the power button for about 30 seconds to discharge any remaining power. Reinstall the battery, reconnect the power, and try booting into the BIOS again.
The front I/O may have shorted. Disconnect the HD Audio cable, front-panel USB and USB-C headers, and the reset-switch header from the motherboard. You can disconnect the power-button header too, then start the system by briefly bridging the two power pins with a screwdriver. If it boots, reconnect the front-panel cables one at a time to find the problem.
Disconnecting the HD Audio cable fixed it. Thanks!
Unfortunately, it still behaves the same way—it powers on briefly and then resets.