PC fails to boot when using OC RAM
PC fails to boot when using OC RAM
Hi,
History:
I purchased an ASUS Z motherboard about five years ago with four 4GB DDR4 modules running at 2666MHz.
The Problem:
The RAMs were initially clocked at 800MHz, but I was able to overclock them to 2666MHz in the BIOS, which resolved the issue. However, occasionally—especially after moving or bumping the PC—I would fail to boot completely. This has been happening since I bought the system.
My Troubleshooting Steps:
I followed a similar process over the years, which I discovered through trial and error. I’m not a tech enthusiast, but I’m an engineer with some knowledge about PCs.
Step 1: Remove three RAM units and install just one.
Step 2: Start the PC; it works with only one RAM installed.
Step 3: Enter BIOS, reset overclock settings to defaults, then restart.
Step 4: Install each RAM individually until all four are running together.
Step 5: Re-enter BIOS and reapply overclock settings.
Step 6: Restart and it functions properly.
Step 7: If I knock the PC and it doesn’t boot again, I return to Step 1 and repeat.
My Conclusion:
I suspect that when I physically disturbed the PC—moving or shaking it—I might have shifted one of the RAM slots, causing it to default to 800MHz while the others stayed at 2666MHz. This inconsistency led to boot failures. By removing three and leaving only one, the system stabilized at 2666MHz, matching the correct setting. When I reinstalled all four, they aligned to 800MHz and the PC started working again.
My questions:
Do you think this explanation matches your experience?
Could the issue lie with a single RAM slot on the motherboard or with the RAM itself? I believe it’s unlikely the RAM wouldn’t boot at all if defective.
Are there any permanent solutions you know of?
Thanks.
Or could be a mis-aligned pin inside the socket, cpu cooler not tightened down correctly and putting pressure on the right side where the memory controller is. Or could be an unstable bios where bumping the ram voltage 0.05v could solve everything. Or the VCCIO. Or the VCCSA.
You bump the pc, and the ram goes funky. You could bang on the side of the pc and it'd still be seriously doubtful you'd get any movement in the ram whatsoever. Having a giant chunk of aluminium that's loosely held in by a couple of screws and hanging well away from the motherboards center of gravity, shake or vibrate or even bounce is a far more plausible situation.
The default speed for DDR4 is 2133MHz. If the RAM locks down, it means the setting is correct—it shouldn’t be loose. I haven’t seen DDR4 clocked at 800MHz before; since DDR2, RAM clocks haven’t dropped that low. It’s unlikely the manufacturer set it that low, as there aren’t any Jedec tables for such a low frequency. The most likely reason is the CPU isn’t aligned properly or there’s a bent pin in the socket, causing the memory controller to misbehave.
The motherboard is an Asus Z170-K. It occurred again today, with four RAM slots in pairs, which explains the two black and two grey slots. I followed the same steps as before until it restarted, then I overclocked all four RAM to 2666mhz, but it didn’t boot. After removing one grey slot from the middle and leaving three 4GB RAMs overclocked at the same speed, it worked again. I’m wondering if there’s a connection problem between the two grey slots or if the middle grey slot has faulty pins?
Or could be a mis-aligned pin inside the socket, cpu cooler not tightened down correctly and putting pressure on the right side where the memory controller is. Or could be an unstable bios where bumping the ram voltage 0.05v could solve everything. Or the VCCIO. Or the VCCSA.
You bump the pc, and the ram goes funky. You could bang on the side of the pc and it'd still be seriously doubtful you'd get any movement in the ram whatsoever. Having a giant chunk of aluminium that's loosely held in by a couple of screws and hanging well away from the motherboards center of gravity, shake or vibrate or even bounce is a far more plausible situation.