sound

[yamca]

i have a 3004-r ps2 with messiah2pro.there is a sound like an electric ark(jýzzt,jýzzt,jýzzt).firts i theink its coming from the movement of the lens.but its coming from the left side of ps2.
i lokk my friends ps2(with messiah2pro) and the same sound coming from it.
is it normal?