X240 does not start until I remove battery and reset.

[Yulana]

This happens frequently. My X240 seems like it has no power -- it is completely dead when I try to start it. When this happens, only way to start it is to remove all batteries, hold down the power button, connect the battery, and then it will work normally until it happens again.

Possibly a related issue is that on rare occasion, the X240 goes to sleep while I am typing on it. I am thinking it may for some reason think the lid is closed (?) and refuses to start/goes to sleep.

I have for now permanently removed the internal battery, so the worst case is it will take about three minutes of tinkering to get it running. Would be nice to not need to go through the hassle every couple of days. Also, this happens periodically -- It stopped doing this for a couple of weeks, then yesterday started again (yesterday, just before this started again, I turned off 30-day standby. Restoring it does not seem to make any difference).

[jursky]

I sometimes faced similar problem with my X240, which looked to be completely dead after re-assembly. For me always worked to take it apart again, disconnect internal battery power cord, then I would just plug it back to the connector, but instead of fully inserting it to the port for power cord, I plugged the cable only into it like for 50% or 75% inside, then my X240 always rose to life. It probably had better pin contacts with the port or I don't know what, the happy news for me was that it just worked and I could use the machine again.

[RealBlackStuff]

Maybe both your machines have corroded internal battery contacts.
Those can be cleaned with some "electronic contact cleaner", either a spray, or a fluid like 90% or stronger isopropyl alcohol.
If a spray, look for electronic, NOT electric.
I have three X240 machines, no battery problems whatsoever.