10-12-2019 03:36 PM
I would try to clean install Windows if I was you. I had this issue and some other software issues and this *knock* *knock* solved all of them.
Replacing motherboard is just temporary, as you can see it may hide a problem for a while but it will surely occur again since it has been software issue.
10-13-2019 02:16 AM
I ordered a Y540 for my cousin and he was really disappointed, because of the audio issue.
I did some investigation and those sneaky lenovo engineers already created a fix, but hid it very good.
The problem mainly seems to be, that the CPU voltages ramp up and down very fast for power saving, leading to a crackling noise at every transition. That also explains, why the sound is fine when gaming, as the CPU is always running at full load.
The fix Lenovo implemented was simply to make those voltage transitions slower and therfore reduce/remove the crackling sound.
Here are the steps I did to fix issue on my cusins Y540:
1. Download an install the latest BIOS from Lenovo's site (BHCN32WW)
-> This will take through a reboot and all, just let it sit and don't touch your notebook while updating
2. Shut down your PC
3. Use a small pin (for example a SIM-Card removal tool from your phone) and poke it into the whole between the USB Port and the Power LED in the right of the Notebook
4. The notebook should start and give you a small menu
5. Select "Setup Bios"
6. Select "Configuration" by pressing the right arrow key
7. Select "Slow slew rate for ia domain" (arrow down) and press enter
8. Select "fast/8" and press enter
9. Press the F10 key to reboot
When you boot into windows now, the sound should be good.
I can't really tell what other implication those settings have (maybe the systems gets unstable, or a little less power efficient), but it worked for us.
10-13-2019 03:18 AM - edited 10-13-2019 03:19 AM
I just made the changes in the Bios settings berniwa recommended and this could be the solution to our misery. I will make another post later on and say again if I experienced any crackling.
If I do I will reinstall Windows 10
10-14-2019 11:58 AM - edited 10-14-2019 12:00 PM
Wow - incredible. Not only did this fix the audio crackling, but it also solved the audio desync (on battery) for me.
PS: you don't need to use a pin to go into the BIOS, just hold shift when pressing restart; go to Troubleshooting; select UEFI startup.