Computer randonly reeboots. Not heat derived

To cut a story short…

The original computer got to go threw 6 sequencial energy blackouts and restarts.

So far it’s got everything new except RAM, 1 IDE cable, and 1 dvd writter.
The rest is from a computer I had here. That one was perfect. Not one error since installed, nor abnormal behavior.
So those are ruled out.

I’ve put the RAM threw 10h of memtest86 without showing anything wrong.
The DVD reader has been used to install things all this time so the last thing left by elimination is the ide cable.

There was something weird with their logitech wireless keyboard and mouse… It stopped working because of this.

The error always has the ID event 1003. This is in both motherboards, and out of all the reinstallations, formats, and diferent hdd configurations.

I’ve searched in for this ID event, and it showed something that just had no chance of being related.