Solved! Laptop shutting down after a few secs (no POST)

[ZRace]

Hello everyone,

I got a laptop here (HP Pavilion 17 ab031ng) that won't POST anymore. Fan starts spinning, LED on power button turns on, and after 5-10 seconds, it shuts down again.

No beeping, no image, nothing. Note that I consider myself well-versed enough that I really want to try and repair it.
What I've tried so far (and didn't work, hence the thread):

1. Power on with only battery/only PSU/both connected
2. Power on without and with different, working RAM sticks
3. Power on with different PSU (also HP, same behaviour)
4. Combinations of all of the above

DVD drive and HDD/SSD were all disconnected.

What I'd like to know is whether there's anything else I can do to narrow the source of the issue? Is it definitely the motherboard or the CPU or GPU on it - which is what I suspect?

Or is there any other part that's not on the motherboard that could be causing this?

I'm not against getting a new mobo (CPU and GPU are both soldered, so they'd get swapped too), but I'd really dislike spending money on it only to find out something else was the problem all along.

Hope someone can help me out here

 

[ZRace]

In case anyone ever finds this thread having a similar problem:

In the end I got myself a new mainboard (obviously with CPU and GPU, as they are soldered on this model) and the laptop is now working just fine again!