On December 1st, I encountered an issue with an old desktop computer (3rd generation) that would not start. After pressing the power button on the main unit, there was no response at all. After ruling out the possibility of a power supply failure, I ultimately confirmed that this issue was caused by a dead 2032 CMOS battery.â–³ 2032 CMOS batteryAfter confirming the power supply line to the motherboard, it was clear that the computer’s power supply was functioning correctly. I used the power line testing method I had learned: unplugging the power line from the main unit and performing a power test. Using a pair of household steel tweezers, I touched the fourth (green) and sixth (black) wires in the motherboard power line. Instantly, the fan in the power supply started spinning, and the LED decoration lights on the main unit lit up.This indicates that the power supply is fine, so I reconnected the motherboard power line. Since I had recently cleaned this old computer, I did not suspect any issues with the RAM or graphics card connections.I used a simple method to verify that the 2032 CMOS battery on the motherboard was completely dead. In fact, this was the most suspect component, as the computer had previously shown symptoms of a failing battery. The startup date had been displayed incorrectly multiple times, always showing the last shutdown time, requiring manual updates to sync correctly.Knowing that the 2032 battery used in my car key was the same model, I temporarily removed the 2032 CMOS battery from the computer’s motherboard and swapped it with the one from the car key. As a result, the computer started normally, but the key’s indicator light did not turn on. This confirmed that the original 2032 CMOS battery on the motherboard had indeed failed.Ultimately, the reason the computer would not start was due to not taking the previous abnormal date display seriously, which led to the complete failure to power on. I should quickly buy a few 2032 CMOS batteries as a precaution. (Salt Rabbit)
