Problem:
My ThinkPad T490 laptop suddenly disables the built-in battery while running on battery power. The system is dead and cannot be booted again until the battery is physically unplugged and plugged back in.

The phenomenon shows up as if I set the "disable built-in battery" switch in the BIOS.

Containment:
After a few random tests, it seems like described problem only occurs when the laptop is physically moved. (So not sitting on a solid surface).

Suspicion:
I heard that there are laptops that have a switch inside that breaks contact when the case is open. If this is true for the T490, the question is where to find and check this switch.

Question:
I am looking for advice or ideas on how to further isolate or research the problem. 

Welcome to the community forum.

After a few random tests, it seems like described problem only occurs when the laptop is physically moved. (So not sitting on a solid surface).

That suggests a loose connection, perhaps in the cable that connects the battery to the system board or perhaps internally in the battery.

I heard that there are laptops that have a switch inside that breaks contact when the case is open. If this is true for the T490, the question is where to find and check this switch.

I am not aware of such switch in ThinkPads. The procedure for opening the case and replacing the battery is described in the Hardware Maintenance Manual. Follow the instructions and check for a loose connection.

If not the battery then perhaps a loose connection elsewhere in the system. Try tapping the case and/or flexing it slightly to see if you can isolate the location. Also try opening and closing the lid. A loose or faulty cable between the base and the lid could cause this.

Another possibility is that the system could shut itself down if it detects the CPU or GPU getting too hot. If this is the case you should be able to feel a hot spot at or near those chips even with the base cover installed. But this is unlikely in your situation since it wouldn't be related to physical movement.

It does not seem to be related to heat development. I ran a load-intensive rendering for testing, and the temperature increased significantly. Still, the system only shuts down abruptly when I physically move the machine 

I will follow your other suggestions next. 

aha! We seem to be getting closer to the cause of the error.

It is not the battery, nor the lid, and neither a heat problem. 

But when I apply pressure to the case, I can indeed reproduce the described problem. If I interpret it correctly, the problem is in or around the location of the installed NVMe. I will next open the case and apply targeted physical pressure to narrow down the source of the error even more precisely.

Further hints and  tips are of course always welcome.

Good to hear. You're getting closer. Perhaps the NVMe SSD isn't seated tightly into the socket. Try reseating it.

@hausman wrote:

Good to hear. You're getting closer. Perhaps the NVMe SSD isn't seated tightly into the socket. Try reseating it.

Thanks for the hint.
After further investigation, however, it seems I can rule out the NVMe as the source of the error. 

However, when I apply pressure to the nearby unpopulated slot for the Wireless WAN card, I can stably trigger the error. 

At first glance, I can't see any flaws on or around the slot. I will try to take a close up photo and post it here for further investigation.

I would be grateful for any further hints and tips.

@t490-user wrote:

@hausman wrote:

Good to hear. You're getting closer. Perhaps the NVMe SSD isn't seated tightly into the socket. Try reseating it.

Thanks for the hint.
After further investigation, however, it seems I can rule out the NVMe as the source of the error. 

 

However, when I apply pressure to the nearby unpopulated slot for the Wireless WAN card, I can stably trigger the error. 

At first glance, I can't see any flaws on or around the slot. I will try to take a close up photo and post it here for further investigation.

I would be grateful for any further hints and tips.

It could be a crack in the system board. Calling @richk for comment.    

The arrow indicates the area where I can trigger the error with slightly pressure.