I want to get in control of the backlight for my phone buttons (It is a Runbo X5, MTK6577 based).

According to some tutorials I found, I should edit the content of this file:


that is actually a link to this one:


I "cat"ted the content of the file when the backlight was off and on, and I read values of 0 and 255 respectively. So far, so good: that file must be involved somehow then.

Now, all the documentation I found (for instance this one) states that I should manually change that file content according to my will (for instance, 0 if you I the lights to be off), then making the file non-writeable; so that the system can't override the settings.

I did, and it did not worked. Now the file content is not overridden; it stays fixed to 0. However, the button keep getting lit as if nothing changed!

I have the feeling that "/sys/devices/platform/leds-mt65xx/leds/button-backlight/brightness" is just where the information about the backlight status is written but not where it is set, at least here on my unit (that is, a Runbo X5 phone).

Any help would be greatly appreciated, I really want to turn those darn lights off at night.

Thank you!

  • Update: I logcat-ted the phone while turning the LEDS on. Here's what I read: oldButtonBright=false newButtonBright=true when the leds turned ON, and oldButtonBright=true newButtonBright=false after some while BUT the light stayed ON for some more time!
    – Dakatine
    Jul 29 '13 at 9:11

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