iF THE SET is a year or even two old and you have to repeatedly turn it on and on but once it is on it is ok, the problem is in the set's power supply.
All of these sets (every brand) have a "standby Power supply" built into them, it runs 7/24 even if the set is not turned on. One of the areas some companies cut corners on is the filter capacitors in this part of the set: Say the constant voltage is 9 volts and they use 10 volt rated caps, the caps will fail after a year or two from heat.
The reason companies do this is the cost difference say on 10,000 sets between 10 volt versus 16 volt rated caps is a nice piece of money.
If someone opens it and follows the power cord to the supply it will be easy to see, these caps (see photo) have a perfectly flat silver top with creases---any caps puffed up are bad.
Look at the caps and
Before you rate this information let me know what you find, this problem will not just go away and usually gets worse and worse until the unit will not turn on at all.
SD TECH