hi wonder if anyone can help have a tx875 which hasnt been used for a while have had to do ir reset but screen is not playing ball can anyone help

Try resetting the screen while you do the IR reset. When you turn the key to the secret z poition. turn on the POS while holding your thumb in the center of the upper right quarter. when you hear the 4 beeps with the reset quicly move your thumb to the lower left quarter and back to the upper right. You should have to recalibrate the touch screen at that time. I use toothpicks to do that so the sensors are right.