Help please! Macbook Pro 2011 has died?!

[macthekatt]

Hi everyone!
My Macbook Pro 17 2011 does not turn on - completely dead!
It worked just fine until 2021.
In 2021, I changed the battery in an authorized Apple service shop. When I went to collect the MBP, it did not turn on - dead. The Apple genius told me it was a "glitch", took it back to the service room, came back with it after a few minutes, and it turned on normally.
I used it for 1 or 2 weeks after that, without any problems.
As I travel extensively for my job, the MBP was not opened or used since mid-2021.
Now it's totally dead! The charger shows green, but the MBP does not turn on - no sound, no fan, nothing.
I tried various methods found on the internet - resetting PRAM, NVRAM, SMC, opening the back of the MBP and disconnecting/reconnecting the battery, reseating the RAM, disconnecting/reconnecting the HDD...
Nothing!
There was no dust inside the Mac, no liquid spillage on it ever; it was not dropped or abused in any way.
Is there anything else I could try?
I cannot stop thinking about the Apple service "glitch", when it was also totally dead, and the genius took it to the back room and returned it working?!
Any suggestions would be welcome! Thanks in advance!

 

[DeltaMac]

2011 MacBook Pro? Power problems are quite likely to be related to the infamous "radeongate" issue that has always plagued those Radeon-equipped MBPros.

 

[xraydoc]

Battery sitting idle for two years? I think it's likely to be a dead battery.

 

[Fishrrman]

Take the back off. Use a Phillips #00 driver for this.
Take note of where "the longer screws" go. Make a diagram on paper.
Carefully remove the plug between the battery and the motherboard.
DO NOT USE ANYTHING MADE OF METAL TO DO THIS!

Next, plug the charger in.
Hold down the power-on button and KEEP HOLDING IT DOWN.

Does it boot that way?

 

[macthekatt]

@Fishrmann - I tried this, no, it does not boot at all.

 

[macthekatt]

I own another Macbook Pro 17, early 2011, which has also been sitting idle for 2 years. This one did not have its battery replaced, it still has the original battery. It booted with no problem and works just fine (I am writing this on it now).
I tend to think that the "Apple genius" did something to the dead MBP - that is why it did not start after battery replacement - and then fiddled with it to try and hide whatever he did, knowing full well it was going to fail after 1-2 weeks.
It was just pure chance that I happened to leave the country and only found out after 2 years instead of 2 weeks...

 

[DeltaMac]

You could try swapping the batteries between your 2 MBPro 17s.
That shouldn't take more than 5 minutes, as the battery isn't glued in, just held in by 3 tri-lobe screws.

 

[robotica]

try leaving it connected to a charger over night, it may have to trickle charge before it will start charging normally.

 

[DeltaMac]

If the MBPro was left for a couple of years, and the battery was left to completely discharge, then it may never begin to charge from zero. That's a known characteristic of those lithium-polymer batteries, and maybe a result of leaving it sleeping, and not shut off (which does discharge completely within a week or two, particularly if left sleeping on a low charge.) The rechargeable batteries just don't like a complete discharge, and may "retaliate" by not accepting a charge after a discharge.

 

[macthekatt]

I will try to swap the batteries and see if the dead MBP starts.
Thanks a lot for all your suggestions!
Hope for the best!