Sudden power down while working on laptop - can only power up with no battery

Laptop:
Lenovo ThinkPad ts400

Using OS:
Trisquel 9 (based on Ubuntu 18.04 LTS)

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Hi

I was working on my Laptop while plugged in to the mains and it suddenly completely powered down without warning. Initially on trying to re-power up (still plugged in to the mains) it seemed completely dead, but when I removed the battery it powered up fine.

Does anyone have any idea what might have happened here ?
Is it likely to simply be a battery issue (i.e I can simply replace the battery), or might there be something else going on - it looks like the presence of the battery somehow prevents any power getting to the machine.

When initially struggling to power up I got to thinking how I might be able get the data off the hard disk if I could find no way to get power to it. In such a case does anyone know if it would be possible to do this ? Put hard disk in an external drive case ? Or somehow connect to another computer ?

 

The first rule of thumb is that when a laptop won't boot with battery installed but will boot when plugged in with battery out is that you have a shorted battery. If the laptop detects wrong voltages, it shuts down to prevent more damage. You might have shorted out the battery while you were working on it but I doubt it. Most short out when plugged in anyway. A new battery is the first check. They are usually pretty cheap on Ebay. (they might be a cheap made battery thou). Sometimes depending on the amount of data you can copy it to a flash drive. More data would requre an external hard drive through usb. You probably wont be able to put the hard drive in another computer as a boot drive because of driver issues.It will probably have to be used as a secondary drive (non-boot drive)