PS3 Slim 2504a Random shutdowns

I have been trying to transfer all my games over FTP to my HDD on my PS3 today, but at random points during this it keeps shutting itself off.

I checked the Power-Saving settings, but it was all deactivated.
I checked temps, but it wasnt even close to over-heating at any point.

I used Rebug 4.82, but changed to the newest Ferrox.
It happened on both.

i replaced the hdd and psu, too.

The only plugin i have installed is sMan.

i even turned the pots on the psu.

Anyone any idea whats going on here?

 

When you say shutdown, what kind of shut down exactly? Does it just shut off instantly? Does it beep and shut off? Is the red light still on after it shuts down, is it blinking after? Can you resume immediately after it shuts off?

 

red light remains on after, no beeps.
I was using Rebug Toolbox while FTP'ing as using FTP while in XMB is apparently not recommended.
Many people online say that this is the way to go, but today i sent over about 600gb while in XMB and the PS3 did not shut off.

I believe this may be a software-issue.