new guy with folgertech kossel rev b

I got my our Kossel built but I am new to arduino and somewhat new to 3d printing. I got the aduino ide and the rev b firmware and was able to upload it. I then found a video that said I needed to make sure setting for inverting the axis was set to false for xy and z so that it would home in the right dir. and I also slowed to the speed it moved. I was then able to get the printer to home but after that I was not able to get the printer to move using the manual controls and I get the message in repetier that the "printer is stopped due to errors. fix error and restart with m999". I think is also gave a message about extruder off. I had read somewhere that I should use the rev a 20 tooth firmware and tried uploading that. same deal so I went back to the rev b. then I went thru my wiring again and found I had my connection for my z probe on the arduino bassacwards and fixed it. tried it again and same deal. then I did something that may have been stupid.. I disconnected the z prob from the arduino with power on. and then reconnected it. now we cant even home but can turn the fan on and off. is there a way to format or wipe clean or reset the arduino? any help much appreciated. I think im in a little over my head.

this is the error i get in repetier when i connect and now i cant home.

18:17:03.051 : Printer reset detected - initalizing
18:17:03.051 : start
18:17:03.051 : echo:Marlin 1.0.0
18:17:03.051 : echo: Last Updated: Jan 19 2016 18:13:37 | Author: (FOLGER TECH, KosselRev
18:17:03.051 : Compiled: Jan 19 2016
18:17:03.051 : echo: Free Memory: 3849 PlannerBufferBytes: 1232
18:17:03.051 : echo:Hardcoded Default Settings Loaded
18:17:03.317 : Error:0
18:17:03.317 : : Extruder switched off. MINTEMP triggered !
18:17:03.317 : Errorrinter stopped due to errors. Fix the error and use M999 to restart. (Temperature is reset. Set it after restarting)
18:17:06.520 : echoD init fail
18:17:06.551 : FIRMWARE_NAME:Marlin V1; Sprinter/grbl mashup for gen6 FIRMWARE_URL:[www.mendel-parts.com] PROTOCOL_VERSION:1.0 MACHINE_TYPE:Kossel Mini EXTRUDER_COUNT:1
18:17:06.551 : X:0.00Y:0.00Z:0.00E:0.00 Count X: 0.00Y:0.00Z:0.00
18:17:06.551 : echo:Active Extruder: 0
18:17:06.551 : Begin file list
18:17:06.551 : End file list
18:17:06.567 : Error:No Line Number with checksum, Last Line: 11
18:17:06.567 : Error:Line Number is not Last Line Number+1, Last Line: 11
18:17:06.567 : Resend: 12
18:17:06.598 : echo:Active Extruder: 0

Is your hot end thermistor connected to your board? I had a similar problem when testing a printer just had to connect the thermistor.

It tells you right there whats wrong

Error:0
18:17:03.317 : : Extruder switched off. MINTEMP triggered !


Sothis means your temp sensornisnt hook up to the board correctly

thanks ill check that tonight

to troubleshoot i switched the thermsistor with the one for the bed and the error went away. when i built the kit i soldered and extension that came in the kit that had a connector on it to the wires coming from the extruder thermisistor. was that wrong? or perhaps it is damage case it was in the correct slot. i also tried just turning the connector 180 but that didn't fix it.

even when i used the bed thermisistor and the error message went away i could not home or move anything. here is the messages i get when i connect.

20:29:06.496 : Printer reset detected - initalizing
20:29:06.496 : start
20:29:06.496 : echo:Marlin 1.0.0
20:29:06.496 : echo: Last Updated: Jan 20 2016 18:19:38 | Author: (FOLGER TECH, KosselRev
20:29:06.496 : Compiled: Jan 20 2016
20:29:06.496 : echo: Free Memory: 3849 PlannerBufferBytes: 1232
20:29:06.496 : echo:Hardcoded Default Settings Loaded
20:29:09.949 : echoD init fail
20:29:09.996 : FIRMWARE_NAME:Marlin V1; Sprinter/grbl mashup for gen6 FIRMWARE_URL:[www.mendel-parts.com] PROTOCOL_VERSION:1.0 MACHINE_TYPE:Kossel Mini EXTRUDER_COUNT:1
20:29:09.996 : X:0.00Y:0.00Z:0.00E:0.00 Count X: 0.00Y:0.00Z:0.00
20:29:09.996 : echo:Active Extruder: 0
20:29:10.012 : echo:Active Extruder: 0

i unchecked the "has sd card" box in printer settings in repetier but is see the "sd int fail" message? is that something i need to change in the arduino sketch?

just noticed that the "sd fail" is gone after I unchecked the box. now there is a "D init fail" message. any ideas?