What you can do is get yourself a service manual from here:http://servicemanuals.vstore.ca/
They also have spare parts and offer free online advice as you attempt a DIY. The issue is most likely a cold solder somewhere on the power board or some faulty capacitors.
If you want to go in for a long term solution, you can
easily replace the whole power board or just change the faulty capacitors. You
will have to open the back panel and take a look. You can make out which are
faulty, because their caps will be swollen on top. Here's a sample pic of a
bust capacitor (not same model):
Check the specifications of the faulty capacitors, and get the replacements
from your local electronics shop. If you are comfortable with this, you can use
a pair of needle nose pliers to G-E-N-T-L-Y pull out the defunct capacitors.
Once that is done, solder in the new capacitors carefully. If are unsure how to
do this, try to get a friend who knows this kinda stuff to do it for you, or
get a qualified technician.
Warning: If you do not have a background in
electronics repair, or are inexperienced, get a qualified technician to do it
REMEMBER there are very dangerous voltages inside a TV
that can KILL. Be sure to work SAFE when dealing with electricity. DISCONNECT
THE POWER BEFORE YOU DO ANYTHING.
Hope that helps!