08-03-2018 04:26 AM
I have bought X280 one month ago and the screen brightness fluctuates occasionally, about once every 2~4 hours, for a duration of 10~20 seconds. When it happens, the brightness level fluctuates for around 1~2% at a frequency of change around 10 times per second. This issue is more likely (but not always) to happen after waking up from suspend mode, and happens almost every day.
I use lowest (1 out of 1515) or second lowest level of brightness (76 out of 1515 in /sys/class/backlight/intel_backlight/brightness) by pressing Fn+F5/F6 on X280. My previous machine, X201s, can run on a similar level of brightness without any issue.
After doing some experiment, I found that reduce the brightness to 0 (backlight off), and increase to 1 (out of 1515), can reproduce this issue easily.
Just wonder does there anyone running Linux and experienced the similar issue? Is it more likely a hardware design limitation, or a hardware failure?
Note: Contacted Lenovo via online chat, unfortunately they cannot provide useful information because I'm not running Windows. Searched online but didn't find similar issue on X280.
Details as below:
Firmware version as below
SMBIOS type 1 information as below
Manufacturer: LENOVO Product Name: 20KFS05Q00 Version: ThinkPad X280 SKU Number: LENOVO_MT_20KF_BU_Think_FM_ThinkPad X280 Family: ThinkPad X280