X201s - now posting from battery, not from AC adapter

[achat_2]

Sorry to annoy the forum members with additional details on recovering my X201s, but I did some positive steps forward and I would be grateful to hear additional suggestions from the forum members, if any.

In the last few days I have done the following operations:

1) new fan
2) new thermal paste
3) disconnected CMOS battery

Additionally I have discovered that one of my batteries was defective:

Now:

on a good battery (AC adapter NOT plugged )
the laptop posts normally (besides obviously asking for the date in BIOS),
gets into Win 7
works perfectly
temperature stays around 50 (playing youtube videos), fan is working properly,
charges the battery if I plug the AC adapter
goes into sleep mode and wakes up normally with ONLY the battery
goes into sleep mode and wakes up with blank screen if ALSO the AC adapter is plugged in


BUT after minutes (like 30/60)
it freezes or shutdowns with a clicking sound (HD?)


on AC adapter (tried 2 different, both working properly with another X201)

the laptop does not post.
Blank screen with spinning drive and fan working or blinking power light with no fan and spinning drive.

What does it mean?

Something related to the power jack cable/connection to MB?
AND
Something related to the HDD?

Is there any experiment I may try with the docking station to identify the culprit?

Sure I want to try this laptop with a different HD.

What is easiest route to put an SSD in this machine?
I would be ok with a fresh installation of Win 10, if it is quicker, no need to clone the existing HD.
(I should be entitled to a Win 10 licence with the Win 7 key)

thanks a lot in advance,
and sorry again for the very long story on this laptop!

A.

[achat_2]

This little machine is giving me back the efforts of those last weeks:

power on about 5 hours ago and still no shutdown.
it runs cool, about 50 C with 15 firefox tabs open
(nice to see applying thermal past and mounting the new fan was so easy and effective)

Almost impossible for me to say why it does not shutdown now.

Last actions:
-- changed the "when lid close" to "do nothing"
-- at one of the last (of many) attempts to power up an automatic chkdsk started but I was away from keyboard when it finished and don't know what it found.

Is there any record I may go to read?

Only problem i noticed in the last 5 hours is sometimes moving windows on the desktop produces a "tail" effect deleting where it passes for few moments.


A.

[achat_2]

Still the problem with the AC adapter persists.

The laptop powers on and wakes up from sleep only if the AC adapter is disconnected and power is just coming from the battery.
With the AC adapter the HD spins but it does not show any activity (no light on the indicator), no post and blank screeen.

Please if anybody has any idea of what could cause such a strange behaviour let me know.

A.