Printer online but MAXTEMP triggered!? - SOLVED- Marlin default is thermocouple NOT thermistor

Using Marlin Firmware, just got it talking (by changing to version 23 of Arduino software and changing the Pronterface baud to 250000).

When I connect it says:
*************************************************************************
Connecting...
start
Printer is now online.
echo: External Reset
Marlin 1.0.0 RC2
echo: Last Updated: 2012-05-02 | Author: erik
echo: Free Memory: 5609 PlannerBufferBytes: 1232
echo:Using Default settings:
ok T:457.4 /0.0 B:0.0 /0.0 @:0
Error:0
: Extruder switched off. MAXTEMP triggered !
Error: Printer stopped deu to errors. Fix the error and use M999 to restart!. (Temperature is reset. Set it before restarting)
**************************************************************************
I think it's a power problem but I don't know where to start.
If I issue an M999 it repeats the last two lines again:

: Extruder switched off. MAXTEMP triggered !
Error: Printer stopped deu to errors. Fix the error and use M999 to restart!. (Temperature is reset. Set it before restarting)

This part threw me:
I get the same response whether the power supply is plugged in or not, whether it's turned on or not. I'm reading 11.92 volts on the input terminals (bridged the 11A and 5A since the PS is rated at 18Amps).

I also pulled the plug for the hot end thermistor/heated bed thermistor that is on T0|T1 but no change. If I meter the pins it shows 5vdc across both sets of pins.

I also double checked the solder connections on the front and back of all of the boards and they all look good to me. If I messed that up, I don't know how or where.

Anyone ever seen this before?

Edited 3 time(s). Last edit at 08/06/2012 12:07PM by a_shorething.

Maybe damaged Arduino pins. You do have the thermistor tables set correctly in the firmware, right? The temperature should read 0*C if you do not have a thermocouple attached.

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Marlin is set to use a thermocouple by default and you will need to set it to read a thermistor before you will get readings.

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@Newperfection
Thanks, I'll check again for any damage, but you mention a thermocouple and as sublime says, I'm using a thermistor from the J-head hot end kit. Maybe that's the issue.

@sublime
OK, that's interesting. Thanks, I'll check that out.

EDIT: I used the sprinter code that is part of the RAMPS wiki and it looks like it may be working. I tested the hotend and bed so far, motors next...

I appreciate the feedback gentlemen. Sorry I'm such a noob at this. So many variables...

Edited 2 time(s). Last edit at 08/06/2012 12:07PM by a_shorething.

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Mike

itsa3dworld.blogspot.com

I get the same message when connect the RAMPS 1.4 to Pronterface but I do not know how to use the code. Just copy the code from Wiki and paste it to Configuration.h over Arduino and then save it?

I would appreciate some help with this.

Thanks

I am also new to this but I looked into Marlin.pde at configuration.h under thermal settings. For the hotend sensor, the first entry listed after the definitions of various sensors, it was originally set at -1. Referring to the definitions, and knowing I have a thermistor that is 100k ohms, I changed this setting to 1. It now works, and its heating!