My ThinkPad X220 at some point started to complain that there was no power when I plugged in the DC power adaptor. After a while, the power would come and go (signalled by an ominous sound signal) as I moved around with the laptop in my lap, or even when I didn’t move at all. After a while, using the computer became an exercise in finding a «good» position for me and the laptop, and then not to move, at all.

My expectation was that this problem was due to the traditional broken solder joint with a power connector sitting directly on a fixed PCB. When I opened up the X220 however (see guide here, do clean out the fan while you are in there), I found that the X220 power connector was beautifully designed with the connector itself being clamped down and then connected to the motherboard via flexible wiring. I therefore concluded that the connector itself must somehow be bad, even though I was unable to confirm this visually or by measurement.

I ordered a new connector, and when it arrived I did the whole process again, fitting the new connector. That solved the problem… for about two hours. To my amazement, the exact same problem reappeared almost immediately after my «fix».

This called for another, more open-minded inspection of the problem. That is, I opened up the laptop once more, and tried to plug in the power connector while I could see what was happening. This revealed the actual problem:

I first clamp down the power connector, then try to insert the plug.

The connector simply isn’t fixed down properly, and moves away when you try to insert the plug. In other words, the connector itself is not the problem, rather there’s a mechanical problem with holding it in place.

It appears that the root problem is a tiny tab of metal on the laptop housing that is broken off. This tab would be so thin that I’m not even sure it was ever there, but this is the explanation that makes the most sense to me. In that case, even just a moderately excessive push on this connector would break off this tab, causing this issue. You can verify this problem without opening up the laptop simply by poking at the connector from the outside with a pen etc. to see if the connector disappears into the casing.

Having identified the problem, repairing it is in principle trivial. However in practice I found it not so easy. There’s no obvious way to weld or glue a new «tab» or back-stop back on. I ended up just stuffing the area with some material from earplugs, which leaves the connector flexible while still supporting a proper connection. This has worked well for me for a few weeks, although I suspect there are better solutions.

My solution to fix the loose power connector on the X220.