Question Did measuring things on my laptop kill it?

[Naujoks]

I have an 12 year old Sony VAIO Pro 13, which developed a backlight problem.
The backlight circuit is integrated on the mainboard.
I used a multimeter to check out the integrity of some fuses and 0 ohm resistors but didn't discover any obvious fault.
I didn't unplug the battery for those tests.
When I wanted to switch the laptop back on, the power LED comes on for a few seconds, but no fans, no picture or anything else.
The CPU gets really hot though.
When plugging in the charger, the charging LED comes on for a few seconds and then goes out again.
So my question is: was not unplugging the battery my fatal mistake? Is that really the most likely explanation why the laptop is dead now?
Is there any chance of repairing it or is the CPU getting really a sign of it being damaged?

 

[Lutfij]

I didn't unplug the battery for those tests.
If you're using multimeter probes to see if there's a short, you're good with or without a power source connected to the laptop.

The CPU gets really hot though.
If the laptop get's power but you have a black screen that would indicate a short.

When plugging in the charger, the charging LED comes on for a few seconds and then goes out again.
That would mean that the power delivery are of your motherboard is compromised.

Is there any chance of repairing it or is the CPU getting really a sign of it being damaged?
You could try and disconnect both wall adapter and battery power inputs, then remove the stick(s) of ram, then press and hold down the power button for 30secs. Use an eraser to clean the stick(s) of ram, wipe clean off of any eraser lint, then reseat the stick(s) of ram. See if you can power up using only the adapter, not the battery.

It might be repairable but you might not have the tools(voltage injection) nor the knowledge to do so.

 

[Naujoks]

The RAM is soldered on.
I tried powering it on without the battery, but same result.
I've watched so many videos on finding shorts on laptop mainboards and I might even have the right tools for power injection (I think my bench PSU doesn't immediately cut out when it detects a short).
I have IPA to detect any parts that are getting warm. I might even get a thermal imaging camera.
The real art is to find the place where to inject the voltage though.
I'm puzzled though why the laptop should crap out on me just in that moment, when all I did was open it up and measure those few components. I guess things started to go sideways with it when the backlight stopped working. Might these two problems be related to each other?

 

[Naujoks]

I've discovered a short on a certain section of the board (some caps are measuring a short).
Visually I could not discover any suspect part.
I have a thermal imaging camera now.
Where should I inject some voltage now? And how many V and A should I set the PSU set to?
Here's a link to a picture of the mainboard. The shorted area is towards the bottom in the middle, where all the caps are:
https://drive.google.com/open?id=1xD6tTZKXNAEPzFK9EQ82eIxw46qpziJB&usp=drive_fs