sony vaio VGN-FE21B makes a sharp noise when volume is maximum

[rajivmaureen]

this sony vaio vgn-fe21b purchased on 28 may 2006.
the mic AND ear phone sockets have gone faulty...they make a sharp noise when i raise the volume...this problem started suddenly and i have sent the laptop back to sony for reapir under my warranty..it was just 2 months old..two of my friends have the same laptops.none of them have this problem..
when i called they told it was some larsen effect. and asked me to put...they told the speakers are fine..i said to check the the mic and head phone sockets..the reply they gave was Please explain to the customer that it´s a larsen effect and for avoiding that problem he have to adjust his microphone´s volume or simply mute it when he doesn´t use the mic.
they did fix the problem and sent it back, but today after one and a half years it has the same problem again.

can anyone help me

Thanks !!!!!!!

[Thalamus.]

Hi rajivmaureen,

Do you know what Sony did to your Vaio when it was repaired back in July 2006.?

[rajivmaureen]

they changed the top cover around the key board. thats all