Tempreature sensor

Hello, I was doing some adjusting of my printer bed and carriage rials trying to improve my print quality to remove horizontal & vertical lines, and waves in my print I guess from backlash...when I put it all back together, my lcd screen said err min temp, and my left extruder reads 0 degrees... did some searching and sounds like a loose wire or something.

I checked most of the wires for good connection, un plugged the temp sensor wires from control box, plugged them back in, un plugged where the temp sensor plugs in next to the hot end itself...still same err min temp reading on the lcd screen...turned it off on off on....inserted sd cards, tried to print...nothing as far as temp go...same err min temp on the screen and no heat.

so then I cut some kapton tape back and pulled the sensor out of the hole it was in...here is what it looks like, I guess it looks fine? I did see some black stuff on the brass block..not sure what this is or if this caused the problem..

Would if be possible for you guys to send me a replacement wire/sensor set up to see if that's the problem, michael rudy (gmax1.5xt owner) said that's what you guys did for him and it fixed the problem.