07-07-2018 01:18 AM - edited 07-07-2018 01:19 AM
+1 on this topic, and I should have read this thread before updating to 4KCN43WW. To my disbelief, after the update:
The fact that the BIOS defaults the SATA controller mode setting to Intel RST Premium after the update also didn't help, as it made the Windows boot loader unable to find the boot disk. Flashing back to 4KCN40WW (and reversing SATA controller mode to AHCI) fixed these issues.
The reason I bought the Y520 is that I was impressed with the performance and stability of the Y510P I got a few years back (and consistently updated), so I was quite disappointed by this. Bad form on the part of Lenovo, in my opinion.
08-14-2018 09:15 AM
This thread includes links to the various BIOS versions for the Y520: https://forums.lenovo.com/t5/Gaming-Laptops/Legion-Y520-and-Y720-BIOS-update-links/td-p/4087757
I flashed back to 4KCN40WW, myself.
08-17-2018 09:37 AM
Yes, there is a change log, it's available on the BIOS download page: https://pcsupport.lenovo.com/nl/en/products/laptops-and-netbooks/legion-series/legion-y520-15ikbn/do...
Based on its contents, I am not going to upgrade straight away; it doesn't mention fixing any of the issues that I ran into with version 43.
08-17-2018 10:10 AM
08-22-2018 02:20 PM
I "upgraded" from 40 to 44 today, and that's why I'm here. Windows won't load. On my Y520, there are only two things out of the normal that I can think of. I removed the HDD altogether and just run with the SSD, which has been going fine for months. And I have a problem where Vantage tells me the batter is almost out of power when it fact it's plugged in and at 100%. It used to cause it to go to sleep, but somehow I got that to stop. So now I'm trying to figure out how to get back to 40 since none of the other troubleshooting has helped.
08-22-2018 05:25 PM - edited 08-22-2018 06:37 PM
Thank you for the links, but how do you downgrade the bios from a flash drive? We've tried running the exe file from the command prompt after enabling bios flash downgrade in the bios setting.
EDIT because I can't figure out how to delete this. We figured it out! Once you insert the flash drive you have to go into advanced settings, then bios settings, then press F9 to reset to default and F10 to save and exit took us two hours to figure it out but worked like a charm.