X670E PG Lightning no POST on cold boot
Printed From: ASRock.com
Category: Technical Support
Forum Name: AMD Motherboards
Forum Description: Question about ASRock AMD motherboards
URL: https://forum.asrock.com/forum_posts.asp?TID=113331
Printed Date: 02 Nov 2025 at 9:18pm
Software Version: Web Wiz Forums 12.04 - http://www.webwizforums.com
Topic: X670E PG Lightning no POST on cold boot
Posted By: BeerGogglesFTW
Subject: X670E PG Lightning no POST on cold boot
Date Posted: 17 Sep 2025 at 9:24pm
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I'm having an issue with my ASRock X670E PG Lightning using the latest BIOS 3.40 I'm enable to boot with EXPO on, every time after the power supply has been turned off and back on. Completely cold boot. I've been on 3.40 for the last 12 days no issues. However, last night I lost power in my house. PC was off at the time. Tripplite surge protector. A-tier power supply... However, the PC wouldn't boot after that. Fans on full. RAM and CPU red lights on. Gave it a few minutes, thinking memory training. Haven't had to deal with anything like that since 2023. No good though. Not booting. Reset BIOS. (Actually, reinstalled 3.40).. Good to go again. Set up my BIOS how I like it. EXPO on... etc. Boots up. Ran stress tests. Gamed for an hour. No issues. Shut down, boot up. No issues. Shut down, turn the power supply off and back on. PC won't boot again. Fans on full, RAM and CPU lights on. Not booting. Shutdown. I replaced the CMOS battery. Repeat steps. Set up BIOS settings. Shutdown. Then shutdown and turned off power supply. Back on and won't boot. Rolled back to 3.30. Set up bios. Shut down. Turned off power supply. Turned back on. Booted right back up. Chances are in the last 12 days since 3.40 release on my motherboard, my power supply had never been turned off. Everything works fine, even under heavy stress. But as soon as the power goes out, I can't boot with 3.40. It seems I'm not alone. I found a few others on reddit with this issue. My RAM is TEAMGROUP T-Create Expert CL30 6000MHz. Could be related. Cheers. |
Replies:
Posted By: Xaltar
Date Posted: 17 Sep 2025 at 9:37pm
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Open a https://tw.asrock.com/events/tsd.asp" rel="nofollow - support ticket with ASRock. Unless it turns out to be a setting in the BIOS there isn't much anyone here on the forums can do to help. This will require ASRock's attention. ------------- 
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Posted By: vrock442
Date Posted: 19 Sep 2025 at 5:18am
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I have similar issue and already posted it on another thread. But I have not used the PC long enough to test previous BIOS versions. Did you just first encounter this problem after updating BIOS to 3.40? And never before? Did you manually set Context Memory Restore or Power Down Enabled, or some other BIOS setting except EXPO OC profile? |
Posted By: DontAsk
Date Posted: 20 Sep 2025 at 5:49pm
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Hi, my system is also affected by this bug in the BIOS 3.40. Reverting to an older BIOS like 3.30, 3.25, 3.20, etc. will immediately resolve this cold boot issue, which only occurs after unplugging the PC from the power supply. CPU: 7900X3d RAM: Corsair Vengeance 64GB Kit CMK64GX5M2B6000Z30 @ 6000 MHz and activated EXPO I reverted back to BIOS 3.30 as long as this bug in 3.40 or a newer one is not fixed. |
Posted By: NDRE28
Date Posted: 20 Sep 2025 at 11:50pm
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Hi! Everyone here posting about EXPO RAM issues seem to have the same speed: EXPO-6000. I'd suggest loading the EXPO-6000 profile, then changing the DRAM speed to DDR5-5600. This way, the timings & voltage will remain as set by the EXPO profile, and only the frequency will be lowered. Please keep in mind that every AMD CPU on the AM5 platform supports officially up to DDR5-5600! Running memory above that frequency successfully is not a given! Some IMCs will handle higher frequencies, some won't! It's all about the silicone lottery. |
Posted By: DontAsk
Date Posted: 21 Sep 2025 at 4:51am
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Hi, in this case it has nothing to do with the EXPO setting and also if it's set to 6000 MT/s or even higher. The issue is that after unplugging the power supply only the BIOS 3.40 can't boot the PC anymore. So if you e.g. lower the RAM frequency and it starts thereafter then that indicates that either not all relevant BIOS settings for a successful boot process are stored in the CMOS correctly or that the stored values are incorrectly evaluated during the boot process after a power outage. If I use BIOS 3.30, 3.25, 3.20 and even older ones this issue doesn't exist at all. The RAM runs even with EXPO 6200 MT/s, CL28, FCLK 2200, UCLK=MEMCLK, and VSOC 1.225V stable as a rock. So long story short, if all other BIOS versions don't have this issue except the 3.40 then it's clear that there is a bug in BIOS 3.40. |
Posted By: NDRE28
Date Posted: 21 Sep 2025 at 3:08pm
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Hi! You might be right, about going back to an older BIOS version to remove the issue. However, it's also a possibility that even with an older BIOS, you'll start to encounter the same issue. Why is that? Simply because EXPO (just like XMP) is an overclock! It may run perfectly for a few months, or even years, and find out one day that it's no longer stable. I've seen that time & time again, through the years. |
Posted By: vrock442
Date Posted: 22 Sep 2025 at 3:43am
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I replied in another topic but might do it here as well. tl;dr cold boot doesn't POST, tried various fixes, finally changed to different RAM kit and it works fine now |
Posted By: DontAsk
Date Posted: 27 Sep 2025 at 1:21am
| Next week, this motherboard will likely be one of the last to receive BIOS v3.50 (includes Agesa 1.2.0.3g). Hopefully, also the above mentioned cold boot bug which only exists in BIOS v3.40 has been silently fixed. We will see ... |
Posted By: DontAsk
Date Posted: 04 Oct 2025 at 2:12am
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Unfortunately the new BIOS 3.50 continues this bug from BIOS 3.40. Back to BIOS 3.30 and no issues. BTW, I use a power strip with a switch thus if I switch the power on that strip and press the power button at the PC it always starts without issues since the last 2 years but only with BIOS versions older than 3.40. With the versions 3.40 and 3.50 it will never start. |
Posted By: vrock442
Date Posted: 05 Oct 2025 at 4:13pm
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Latest BIOS 3.50 is not targeted at this issue. My research shows most users with similar issue can pass a cold POST only if they run the PC for a while and then restart it. So this is most likely a power delivery on start issue. E.g. faulty PSU voltage line to CPU or mobo, faulty BIOS battery, anything related to voltage power droop when capacitors are discharged for cold boot (could be PSU, CPU or Mobo hardware problem). Problem may be partially or fully remedied by swapping components or changing voltage settings in BIOS. |
Posted By: Limpster
Date Posted: 05 Oct 2025 at 8:39pm
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Just wanted to chip in and say that I got the same issue after updating the BIOS to 3.40 (and also 3.50) with cold boot. Downgrading to 3.30 solves the issue. Had the same issue back in the day with my ASRock Z170 OC Formula after cold boot, never solved it (even changed CPU, RAM, Power Supply and GPU without success) and got myself another board (different brand), worked plenty of years without any troubles with the new board. I don't see the point in changing my hardware when the problem is -as it seems- BIOS related. My components are brand new, working flawlessly with 3.30. The issue is the BIOS or some setting (related to the newer BIOS versions) which I coulnd't figure out yet. The problem only occurs to me when shutting the pc down and cutting the power completely (removing power cord/switch the power strip off), but if I just shutdown the PC and restart it the next day/hours later without cutting the power, it boots fine (no such issue with 3.30). It also doesnt matter if I leave the RAM at default settings (=not EXPO/OC related in my opinion), PC won't boot after cutting the power. |