T470S suddenly stopped booting. Screen keeps black while everything else seems to work

[irock]

Hi there. I have a T470s that originally came with Windows. I formatted the disk and installed Linux Mint on it as my sole OS more than a year ago.

Everything has been working flawlessly, with the exception of the electric part. At some point, one of the batteries just stopped holding any charge altogether, so I started depending on the AC cable and the other battery, which would then obviously hold much less charge than at the beginning, but still functions well.

Also, at some point, the charging led on the power button would suddenly start turning off and on again randomly, even though the charger never seemed to stop passing electricity through -- I never noticed any warning like 'charger disconnected'.

Anyway, some time ago I started going to bed with my computer playing YouTube stuff, without the charger connected, until the battery depleted. Then on the morning it would be as easy as plugging the AC cable and turning the computer on.

And then one day I was no longer able to do that. Now when I press the power button, the LED on it, the whole backlight keyboard, the LED on F keys and others (like F1, F4, Esc and Caps lock) and even the red dot on the lid, all turn on. Even the fan ejects some air -- though it doesn't sound, however I'm not sure if it used to every time I would the computer on. However, the screen stays black and there is no booting beep.

Also, I've noticed that while the computer is turned on, if I close the lid, the red dot on it will stay on instead of blinking, which seems to indicate that the system is not able to suspend like it used to.

What could be happening and is there anything I could try out?

[RealBlackStuff]

Looks like you are a murder suspect (of batteries)...
Remove the other big battery, then try again.

[irock]

Looks like you are a murder suspect (of batteries)...
Remove the other big battery, then try again.

Excuse my noobness but is it safe to open up my ThinkPad if I can't access the BIOS first in order to disable the batteries?

Also, are there some keyboard shortcuts I could press while turning the computer on to try out some stuff?

[RealBlackStuff]

Just switch off, unplug power supply, open it up and remove both batteries.
Plug power supply in and try again.
Let us know what happens.
If it boots again, then both batteries are dead.

[axur-delmeria]

Excuse my noobness but is it safe to open up my ThinkPad if I can't access the BIOS first in order to disable the batteries?

Yes, there's a degree of risk. That's why you disconnect the batteries immediately after removing the bottom cover, before you touch anything else.

[irock]

Looks like you are a murder suspect (of batteries)...
Remove the other big battery, then try again.

I removed both batteries and now it works!

Btw, and once again apologizing for my noobness, I wonder why do I have to do so. Why would two dead batteries imply that the computer won't boot, even when it's connected to the wall? And even so, wouldn't two dead batteries imply that the computer won't turn on at all, instead of turning on but keeping the display off?

I'm a bit confused.

Also, I'm not sure this explains the problem of the lid closing not sending the computer to sleep.

[RealBlackStuff]

A dead battery may short some electronic circuits and thus prevent something from working.
By removing this short (in this case: the dead battery) it usually works again.
For a laptop to sleep, it needs a working battery. Without it, no sleep!

[irock]

A dead battery may short some electronic circuits and thus prevent something from working.
By removing this short (in this case: the dead battery) it usually works again.
For a laptop to sleep, it needs a working battery. Without it, no sleep!

The strangest thing is that if I keep the batteries installed, they can still charge (or at least one of them), as confirmed by the fact that if I disconnect the cable the computer will stay on for a long time.

So much for a dead battery.

[RealBlackStuff]

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