sony 32 tv has no power

can anyone help.  my 3 year old Sony 32 LCD TV model #klv32m1 all of a sudden has no power.  i checked the cord and tried plugiing it into a different outlet.  A repairman looked  at it and told me it was the power supply.  he quoted me $650 for the repairs.  Does this sound like a fair price.? How can i fix it myself? please Help.