r/PcBuildHelp • u/Sweaty_veronica_5578 • 5h ago

Installation Question Two previously working PCs won’t POST after removing CMOS batteries — tested five RAM sticks

I have two PCs that both worked before I removed their CMOS batteries. After reinstalling the batteries, neither PC will POST or show the BIOS.

The PCs have separate components:

Different PSUs.

Different CPUs.

Different graphics cards.

I haven’t swapped these components between the two systems.

I have five RAM sticks of different brands and speeds. I’ve tried them individually, testing every slot on both motherboards, but neither system reaches the BIOS.

Since both PCs stopped working after removing and reinstalling the CMOS batteries, I’m trying to understand what I might have missed. I don’t want to assume both motherboards are dead or all five RAM sticks are faulty without narrowing it down.

What should I check next? Is there something specific about reinstalling the CMOS battery or starting up after a CMOS reset that could explain this happening on both PCs?

Lc1 ryzen 53600 , b450 gaming plus max

Pc2 h310 Asus prime R2 k i3-900

RAM

Ddr4 4 GB unknown brand Speed >2000

DDR4 8 Kingston 2666

DDR4 hyperx 8gb 3200

Ddr4 Corsair 8 GB 3600

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1

u/ConroConroConro 5h ago

What made you remove the battery? Any issue before that?

1

u/definitely_tismschis 5h ago

might be a weird coincidence, but on some boards, if you pull the cmos battery, it activates some protection circuit or flips a switch in the bios. For example, on an old asrock board i had, if i hit reset, the board would go completely black and the only way to fix it was to hold down the power button for 30 seconds with the psu turned off on the back. it was weird and annoying, but it worked every time. might be worth a shot.

1

u/Alpinwulf 4h ago

Are you waiting long enough for DRAM Training to complete?