Update: Looks like dodgy thermistors, something wrong with the connection at the black shrink wrap near the head end.
Now that the guides/firmware are up for this I've given a bash at getting it going, but after going through the firmware install/setup the 2nd hothead is allegedly at -15 degrees on the touchscreen.
- Re-uploaded the Proforge 2s Dual firmware with fresh download
- Verified I chose the Mega2560 board/CPU
- Tested both thermistors which at the time both read 130.2kohm IIRC
- Reseated the thermistor connections
I've checked in the serial console and it sees the -15c too, so it's not a arduino -> lcd issue.
echo: Last Updated: 2018-08-01 | Author: (Makertech 3D)
echo:Compiled: Apr 12 2019
echo: Free Memory: 5185 PlannerBufferBytes: 1232
echo:Hardcoded Default Settings Loaded
echo: G21 ; (mm)
echo:Filament settings: Disabled
echo: M200 D1.75
echo: M200 T1 D1.75
echo: M200 D0
echo:Steps per unit:
echo: M92 X80.00 Y80.00 Z400.00 E98.00
echo:Maximum feedrates (units/s):
echo: M203 X300.00 Y300.00 Z5.00 E50.00
echo:Maximum Acceleration (units/s2):
echo: M201 X1000 Y2000 Z100 E10000
echo:Acceleration (units/s2): P<print_accel> R<retract_accel> T<travel_accel>
echo: M204 P2000.00 R5000.00 T2000.00
echo:Advanced: Q<min_segment_time_us> S<min_feedrate> T<min_travel_feedrate> X<max_x_jerk> Y<max_y_jerk> Z<max_z_jerk> E<max_e_jerk>
echo: M205 Q20000 S0.00 T0.00 X3.00 Y3.00 Z0.30 E10.00
echo: M206 X0.00 Y0.00 Z0.00
echo: M218 T1 X0.00 Y-19.00 Z0.00
echo:Auto Bed Leveling:
echo: M420 S0 Z0.00
echo: M301 P18.48 I1.13 D75.30
echo:Z-Probe Offset (mm):
echo: M851 Z-3.00
ok T:22.97 /0.00 B:22.50 /0.00 T0:22.97 /0.00 T1:-15.00 /0.00 @:0 B@:0 @0:0 @1:0
I've had a look in Configuration.h and it all looks good so I'm somewhat stumped.
Yeah, I've found reseating cables and checking for play in connectors is the most common solution to this -15 issue.
One of my thermistors was damaged in my case and I had to desleeve and resolder near the thermistor, wrapping it back up with electrical tape (though shrink wrap would probably be better).
I had -15 today when re-flashing my marlin. After a lot of faffing around I realised that the bed sensor socket seems to be quite wide and I'd missed the pins when plugging it back in.
For me this happens when the temperature sensor cable is loose or if there is a conflict between usb, octoprint or some other software used together. There should always be one connection only at a time.
-15c on a hotend
Any suggestions ?
I also have this negative reading from time to time... there must be a software problem I think 🤔.
Likely a sign of a bad/shorting thermistor. Check wiring first, but you may need a replacement.