My PC has trouble starting each morning. Resetting CMOS seems to help, but it can still take hours to boot. The motherboard is a Gigabyte A320M. What should I check?
Two CR2016 batteries were stacked in place of a CR2032 while the power supply was unplugged. Could that have damaged the board?
Remove the stacked batteries before trying again. Two 3-volt cells stacked in series can supply around 6 volts to a circuit designed for a single 3-volt cell. The PC being unplugged does not prevent the batteries from powering that circuit.
Damage is possible, but it is not proof that the motherboard is fried. With the PC unplugged, remove the cells and fit the correct single battery specified for the board when one is available. Don't keep experimenting with stacked cells.
A weak CMOS battery can cause the clock and firmware settings to reset when power is removed. Replacing it is worth doing, but the long startup delay points to something else that still needs diagnosing. Resetting CMOS may also change boot settings, so check those after a reset rather than assuming the reset fixed the underlying problem.
First narrow down what “takes hours to boot” means. Does nothing happen when you press the power button, do the fans run without a display, or does the firmware screen appear quickly and the operating system stall afterward? Those are very different problems.
If it won't power on or show a firmware screen, the power supply is one possibility, as are the motherboard and other hardware. If it gets past that stage and hangs while loading the operating system, check the boot drive and its connections too. A known-good compatible power supply is a more useful test than guessing from the symptoms alone.
Be careful interpreting a multimeter continuity beep on a motherboard. A low reading somewhere on a power rail doesn't by itself establish that the board is bad, and the measured points matter. If you aren't comfortable testing components, a repair shop can help check the board and power supply before either gets replaced.
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q17!rclk_604:
It may help to note whether the clock or firmware settings are lost after the PC has been unplugged. That can separate a battery problem from the startup problem.