2007 Toshiba 26HL67 tv wont turn on or off

I have a 2007 Toshiba 26HL67 tv, serial #AM338001885 was having trouble with remote not being able to turn on or off but still able to power on by side button and use remote for everything else, now tv got turned on and would not turn off with any button including side power button , had to unplug to power down , now tv will not turn on at all . I have checked the switches on side of tv with meter and they are in working order , only light on tv is a small green light I can see from looking inside of lower back of tv, power is fine all the to circuit board also . Anyone familiar with this problem and cost to fix?