Question PC won't POST after changing the RAM speed ?

[rouema]

I just bought a new Gaming PC
specs>
mobo: asrock x670e pg lightning
cpu: ryzen 5 7600x
ram: 2 x 16 gb adata xpg lancer 6000 mhz
gpu: rtx 4070 ti

when i first set it up the ram was running at 4800 mhz and was fine, then i changed to its rated 6000 mhz and it works fine, but, when i turned it off, it wont post anymore, i tried reseatting ram, and cleR CMOS, but wasnt able to make it post ever again

 

[Hotrod2go]

Is the board updated with the latest bios? I know with the new 1.0.07b AGESA, RAM OC is easier & higher bandwidth is achievable. I would not attempt to address PC problems unless latest firmware is updated.

 

[Misgar]

Trying to overclock DDR5 RAM at 6,000MT/s with automatic XMP settings is a gamble. Sometimes it works staright out of the box. Other times, it needs a helping hand with manually applied (relaxed) Primary timings and possiby a few tweaks to Secondary timings.

To regain control of the system, pull one stick of RAM and see if it POSTs. If not, pull the other stick of RAM and see if it POSTs. You might get the BIOS to work again when it detects no RAM.

If you can get into the BIOS, disable 6,000MT/s XMP. revert to 4,800MT/s and save the settings. Power off completely, fit both DIMMs, reboot, allow the system to train and leave things as they are.

If you are determined to overclock up to 6,000MT/s, relax CL (CAS) by one or two clock cycles and see if the machine POSTs. If it does, run MemTest86+ for a few hours to check stability.

I'm running 2x32GB (64GB total) DDR5 at 4,800MT/s to maintain stability on my 7950X rig. My apps don't benefit much from overclocking RAM, so applying higher XMP settings is a pointless exercise. Better a stable system than one which stops working.

 

[Misgar]

I suppose it all depends which slots the two DIMMs are fitted in. One combination (A2/B2 or A1/B1) will give Dual Channel. Another combination A1/A2 or B1/B2 will give Single Channel. I'm assuming the mobo has four slots.

I suppose we could also check if it's Single Rank or Dual Rank, but I'm not sure if that would be of any help in this case.

 

[Hotrod2go]

I suppose it all depends which slots the two DIMMs are fitted in. One combination (A2/B2 or A1/B1) will give Dual Channel. Another combination A1/A2 or B1/B2 will give Single Channel. I'm assuming the mobo has four slots.

I suppose we could also check if it's Single Rank or Dual Rank, but I'm not sure if that would be of any help in this case.

Every mother board I've use for many yrs now always has the manufacturer strongly recommending a specific set of DIMM slots for 2 stick kits. If the OP reads the motherboard manual they will see this still applies to todays platforms. Generally, its A2+B2 for successful dual channel config, I've seen this since the days of socket 1156.

 

[rouema]

Is the board updated with the latest bios? I know with the new 1.0.07b AGESA, RAM OC is easier & higher bandwidth is achievable. I would not attempt to address PC problems unless latest firmware is updated.

well, I downloaded the 1.28 bios from the asrock site and flashed it into the mobo, ( had to wait some minutes with the green light blinking, and than it stopped ) I would assume it was done correctly, then i tried turning it on, but no post though

 

[Hotrod2go]

well, I downloaded the 1.28 bios from the asrock site and flashed it into the mobo, ( had to wait some minutes with the green light blinking, and than it stopped ) I would assume it was done correctly, then i tried turning it on, but no post though

If your sure you followed all the steps in the UEFI bios flashback procedure correctly & its still not booting then are you sure your waiting the expected RAM training times as per the description for that version of your bios??

"Update AGESA to ComboAM5 1.0.0.7b
*First boot with XMP/EXPO enabled will take a longer training time than pervious BIOS.
Debug LED will stay at DRAM and flashing a few minute. After that, system will back to the normal boot speed."

There is always this trouble shooting flow chart if it still fails to boot, & if that doesn't work, RMA the board.