Hello, and sorry you're having problems. We are now connected on this website- which saves you money over having a Tech come to your home, and in many cases we can fix the problem you're having. In other cases, these things do require additional parts to fix. But I can help you with that as well.
Offhand the screeching sound and set cycling itself on and off indicates a hardware failure- either with the Power Supply Board (most commonly) or the Mainboard in the set. There aren't any resets or settings that will correct hits and it does require repairs on a component level.
To narrow down between those two boards requires voltage testing inside the set- using a digital multi-meter to see whether the power supply board is producing voltages, or if the mainboard is not providing a steady turn on command. The average cost for this type of repair is between $250-$300 parts and labor at a shop. If you'd like, you can use the link below to locate a tech in your area:
Alternatively, if you're a DIY type and looking to repair the set yourself, you would either need to be comfortable measuring live voltages within the set- or the layman's approach would be to purchase both the power supply and mainboard, then replace one at a time until the set stays on.