12-04-2017 03:28 AM
yesterday my X240 didn't wake up from sleep properly (LED backlight went on, nothing else happened), so I tried to restart it.
When I hit the power button, the following happens:
The power button LED and the Fn key LED light up and stay on.
The red F1 and F4 LEDs briefly light up, as well as the keyboard backlight, but those go out after less than a second.
I can hear some faint noise, the fan probably.
Screen stays dark, no backlight. Connecting an external monitor does not help.
I have tried to remove the power supply and external battery, pressed the Power button for 30 seconds, hit the emergency reset button, no results.
12-04-2017 01:55 PM
There is an emergency reset hole in the bottom to disconnect the internal battery. Disconnect from AC, remove the external battery. Lightly press a straightened paperclip into the reset hole (left of external battery) and hold for 10 seconds. Put the battery back and try again.
12-05-2017 09:52 AM
The external battery must be out for the reset hole to work. The next thing to try is to remove the bottom cover, disconnect the internal battery and also disconnect the yellow backup (CMOS) battery. Wait 5 seconds and reassemble. This will cause problems if you have a supervisor password set and fave forgotten the password.
12-05-2017 11:18 AM
OK, I removed the internal battery and disconnected the CMOS battery for a few minutes. Then I reconnected both and pressed the Power button. The result is similar to what I described in the first post, the only difference is that the Fn LED only lights up after about 3 or 4 seconds (instead of half a second).
However this seems to only happen on the first startup after reconnecting the CMOS battery. After that it's back to half a second.
12-05-2017 11:41 AM
Sounds broken to me. Some X240 machines still are under warranty. Is yours?