Ok, did not know you also have pal console. mine is ntsc. And also sorry to confuse, I usually power with external, but never leave standby power on (solid red light) when connecting external power. But also I have never had issue detecting nand with power on console and all cables attached, and with external power and all cables attached.
Sorry again if confused, my post a few up stated "cord connected (but switch off in back) "
so i leave power cord attached to back of console just flip kill switch also in rear of ps3 before power externally.
Maybe there are more differences in hardware of pal and ntsc power scheme. I will check with my spanish friends to see if they have issues detecting nand with cables and accessories connected.