Delta g2s pro LCD temp sensors go to zero after connection to repitier host

[spanky73]

Put this Delta together in 2015 with the gt2560 Rev a board. It has given me great prints and no problems till now. First my power supply died and replaced that and everything worked fine again. Less than a week later I went to print and the LCD showed a mintemp error and then nothing would work. Something seemed wrong when I was connected through the USB port only without the power supply on. It showed the same error but was fuzzy around the top and edges of the display. Turned power supply on and everything was bright on display but with same error. I had another GT2560 controller board and replaced the old one. After powering printer up LCD showed ambient temp on both readings. I thought I had it taken care of. I turned on main power and proceeded to flash the new board. It Flashed perfectly with no errors. I booted up Repetier Host and went to connect it to my printer. (clicking the icon to connect.) That was it the error came back and nothing worked. I have used this Repetier program all the time with no issues. Why should connecting it to the printer do this. It flashed just fine so the USB cable should be fine. Im lost! Any thoughts