Im not sure if this is an answer, but im having the same problem...We bought a samsung SP42Q2 and within a few weeks we had this problem...luckily it was still under the warrenty so a replacement was sent...Now only a year down the line and just 2 months out of warranty its happened again! The same "squealing" sound and going back to standby! So unless you still have a warranty then im afraid i cant help! But anyone with any know-how, your input would be much appreciated.
Many thanks
Karl, August 2007
