X250 strange problem

[Swonco]

Hi Guys,

Strange and interesting problem with my Thinkpad.

Subject: Thinkpad X240 with motherboard from X250 (original had 3-3-1 error). New RAM, new CMOS battery, BIOS updated to the latest version (1.42).

Problem: After motherboard reset (CMOS battery unplugged and plugged again) computer starts, boots, Windows load and everything works like a charm. Of course during first run errors 0251 and 0271 appear, but after updating the time and save/restart computer does not notify on any other errors. I can "soft" restart computer (either from BIOS or from Windows) and it starts again. But, if I cut out the power, using "shut down" or "hibernate" in Windows or unplug the main power, computer failed to start. Completely. No reaction on power button, any LED on keyboard light, no beeps. Mother board reset and it is alive again. Until next shut down. External battery and/or internal battery in or out - no differences.

And it starts to be interesting - I tried to check what will happen when CMOS battery is completely out. Computer boots as after mainboard reset. Power off = dead computer. But this time (only main power, without battery) it was enough to only unplug power supply to revive (quite obvious I guess). With external battery added - dead until battery removed.

So it seems for me that BIOS registers power off event and prevents to start computer again. Some security settings perhaps? Loading default settings from BIOS did not help (yes, I know that security and time setting are not changed). Any ideas?

And by the way - how to install this small plastic element that supposed to be mounted to the mainboard next to the external battery plug? I was able to remove it but not re-install.

[Al3x0]

My X250 also has the same issue , it works just fine when i power it, the only problem is when i shutdown/suspend it enters a dead state.
I can power it up back by removing all the battery cells and the CMOS battery, I have read some post from Lenovo which recommend swapping the CMOS battery. So I do not know if you managed to fix yours.

[RealBlackStuff]

In BIOS, go to Config/Power and DISable "Power On with AC attach", press F10 to Save and Exit.
Switch laptop off and remove main battery and charger.
Press on the Power button and hold it down for 20 seconds.
Plug in only the charger, don't touch any buttons.
Does it power ON?
If not, press the Power button, does it now power ON?
If not, you have a faulty Power button.
Check the X250 manual (from the HMM link above) how to replace the "1150 Power-button card".
Until you get the new card, go back in BIOS/Config/Power and ENable "Power On with AC attach", press F10 to Save and Exit.
When you now switch the laptop off, also unplug the charger.
To (temporarily) start the laptop, plug the charger in and it should boot.
With the new power-button card in, repeat only the first line of this post.

[Al3x0]

I have followed everything from your solution but sadly
It is not working, the system can't power on using the power cable. I have to disconnect the battery the cmos for it to power up, for now I just use sleep mode, It's a replacement motherboard which I ordered from Aliexpress, if you have any idea of what might be the issue, I will be glad for your feedback.

[RealBlackStuff]

Maybe you also have a dead CMOS battery?
A good working one should have between 2.7V and ~3.3V.
Any lower, replace it.

[Al3x0]

I am getting a 2.99v which means it's fine, but since it's a motherboard from China, I have read some forum which says it might be one of the test models. It means maybe I bought a test version of the x250 motherboard. I also contacted the the seller, 亲爱的朋友，主板需要放电使用
That what he said, which translate to "the motherboard need to discharge the use" , I don't get what he's trying to say though

[RealBlackStuff]

I repeat:
In BIOS, go to Config/Power and DISable "Power On with AC attach", press F10 to Save and Exit.
Switch laptop off and remove main battery and charger.
Press on the Power button and hold it down for 20 seconds. (what the Chinese seller probably meant, it discharges static electricity)
Plug in only the charger, don't touch any buttons.
Does it power ON?
If not, press the Power button, does it now power ON?
If not, you have a faulty Power button.