Lenovo Legion 5 Pro stopped working and not booting anymore.
Lenovo Legion 5 Pro stopped working and not booting anymore.
The 2021 Lenovo Legion 5 Pro stopped responding after a Windows update. It's not certain if the update caused the problem. A BIOS reset was tried by re-flashing firmware from Lenovo's BIOS update, but it restarted normally with lights and fans working, then entered BIOS self-recovery which finished without booting. The screen only activated during recovery and no HDMI output appeared. It occasionally restarted randomly, showing the Wi-Fi module as inaccessible in Device Manager and failing to start in the diagnostics tool. After a full Windows diagnostic, only the Wi-Fi issue was found. Removing the device didn't stop it from not booting. Fastboot was disabled to rule it out. Hardware appears intact but performance remains poor. The laptop was purchased in February 2022 as a showroom model. It has been used heavily since then. Key specs: Intel Core i7-11800H, NVIDIA GeForce RTX 3070, 16GB RAM, 1TB SSDs, Samsung and Kingston storage. OS is Windows 11 Pro 64-bit, version 25H2 with Safeboot and Fastboot disabled. BIOS error code H1CN58WW was logged intermittently. No clear resolution found so far.
I thought it might help to have a clear picture of what happened. The problem started right after the final Windows 11 release (version 25H2). When the system restarted because of the update, it froze on a black display. After waiting about half an hour, I powered off the laptop. Even though this wasn’t perfect, it hadn’t caused any lasting damage before. The next day I tried to start it again, but it didn’t boot up properly.
The keyboard backlight would turn on automatically, the logo on the back would light up, and the power indicator would activate—but there was no sign of a successful startup. I waited a while, then shut it down again, but the issue repeated.
When I reached out to friends for help, they thought the BIOS might have been damaged during the forced shutdown, possibly while a BIOS update was happening. We tried several key combinations to get into Lenovo’s Novo menu in an effort to recover the BIOS. None worked.
A friend who had dealt with similar problems offered to assist. He removed the original BIOS and tried to install a version from Lenovo’s update tool (he likely tweaked the file slightly). This didn’t work, so he restored the original BIOS dump. After a few power cycles, the laptop started working again. It booted mostly normally, but sometimes it wouldn’t, usually after entering the BIOS settings and not making any changes.
In those cases, the system would automatically try to recover the BIOS, then restart. I left it in that state for a while while doing other tasks, and eventually it worked consistently on both Windows and Linux—except after booting into MemTest. To rule out RAM issues, I swapped in different memory sticks, but the problem persisted. All accessible parts like SSDs and the Wi-Fi module were tested and didn’t cause trouble.
Eventually, my friend returned the laptop. It booted normally for a while, then after 11 days it refused to shut down. I left it there for over an hour before forcing a shutdown. When I tried to restart afterward, it went through power cycles again. Occasionally it would attempt a BIOS self-recovery, but that didn’t succeed.
I usually stopped the power cycling by doing a hard shutdown and leaving the system off for about 30 minutes. This helped it boot three times in two days. Once in Windows, everything seemed fine except the Wi-Fi module, which showed problems in Device Manager and the Event Log (see screenshot). I ran Lenovo’s full diagnostic suite—no critical errors except the non-functioning Wi-Fi. Stress tests for CPU, GPU, and memory also completed without issues.
I repeated the reboot process to see if it would post again, but diagnostics still only flagged the Wi-Fi module. I also ran tests on the processor under load. The only consistent pattern was that after a BIOS update or reset, the system would either recover or keep failing to start.
One thing to remember is that sometimes the laptop could restart itself if I held the power button for about 20 seconds until the power indicator stopped flashing. I’ve also noticed that holding the power button for roughly 20 seconds seems to stop it from turning back on.
I don’t think the BIOS got corrupted during an update, as the latest version for this model was released on June 14, 2024 (H1CN58WW). I’m confident I installed it correctly before that date. If it had been updated to a newer release, a further update would be unlikely. There was no warning message on screen about a BIOS update, unlike when using Lenovo’s official upgrade tool.
You mean the external power brick or the internal part? It looks like the external brick is working well at 300W, while the USB-C is only providing 100W.
It looks like a possible hardware issue on the mainboard. This might not fix the problem long-term, but you could attempt to reset the CMOS. Take off the bottom cover, disconnect the main battery, then detach the CMOS battery gently, and hold the power button for about 30 seconds to discharge the caps.
Hi, I thought this was already addressed during the BIOS re-flash process, so I repeated it. When I powered it on normally, the keyboard lights, fans, and other components activated as expected. However, the screen backlight briefly illuminated before turning off again. After waiting half a minute, it attempted another BIOS self-recovery, which failed again, causing another power cycle. Using my stopwatch, I measured each cycle to be around 45 seconds. I’m not sure if this data is useful, but it seems like the system might be triggering an automatic fault detection after a period of inactivity. Edited January 15 by nbsp Added details about the power cycling process.
I also thought the capacitors were my assumption. It seems there might be various power distribution paths that aren't always active. If a faulty capacitor existed in a circuit only occasionally used by the BIOS, it could account for why the system feels stable during startup.