Sounds like you probably need to replace the capacitors on the power supply circuit board. Also certain Santos have copper strips with IC chips glued onto them that can become lose. I'd need to have a picture of the screen while the TV is turned on to better tell which!
Try resetting the alarm by rolling down the driver side window, locking the door with the inside switch and shutting the door then unlock the door with the key fob!
It would depend on what size screen and model you have. If it's the correct one I have a couple new screens I'll send you one for the price of shipping.