No temperature reading in Pronterface

[b8smat]

My M2 has suddenly decided not to report any temperatures back to Pronterface.

Pronterface seems to connect just fine (last thing it says is SD card is OK). But nothing I do gives me back a temperature reading. Not the graph, the status bar nor the console window. Sending a manual M105 command has no response from the printer.

Attempting to set the extruder temp has no effect either.

[ednisley]

Pronterface seems to connect just fine

If you can cut-n-paste the entire output here, that will provide some way to identify the problem; otherwise, there's not much to go on. Knowing if you're using Linux / Windows / Mac will help.

Almost certainly, the lack of temperature reports isn't the first thing going wrong.

[b8smat]

Here is the output (this is on Windows 7)

Code: Select all

Connecting...
start
Printer is now online.
echo: External Reset
Marlin 1.0.0
Using tool 0.
echo: Last Updated: Apr 26 2015 20:59:26 | Author: (none, default config)
Compiled: Apr 26 2015
echo: Free Memory: 4141  PlannerBufferBytes: 1232
echo:Hardcoded Default Settings Loaded
echo:Steps per unit:
echo:  M92 X88.88 Y88.88 Z400.00 E471.50
echo:Maximum feedrates (mm/s):
echo:  M203 X500.00 Y500.00 Z25.00 E25.00
echo:Maximum Acceleration (mm/s2):
echo:  M201 X4000 Y4000 Z100 E10000
echo:Acceleration: S=acceleration, T=retract acceleration
echo:  M204 S2000.00 T3000.00
echo:Advanced variables: S=Min feedrate (mm/s), T=Min travel feedrate (mm/s), B=minimum segment time (ms), X=maximum XY jerk (mm/s),  Z=maximum Z jerk (mm/s),  E=maximum E jerk (mm/s)
echo:  M205 S0.00 T0.00 B20000 X8.00 Z0.40 E5.00
echo:Home offset (mm):
echo:  M206 X0.00 Y0.00 Z0.00
echo:PID settings:
echo:   M301 P25.89 I1.94 D86.53
echo:SD card ok
SENDING:M105
SENDING:M105
SENDING:M105

[ednisley]

this is on Windows 7

That dump looks pretty much like it should, so peek under the hood.

The RAMBo board (Rev 1.3) has two amber LEDs just behind the USB connector, that light when text passes through:

• Left = transmit (closer to Reset button)
• Right = receive (closer to endstop jacks)

When you reset the board, the Transmit LED should blink merrily as the firmware sends that startup text to the PC. The Receive LED should then blink as S3D sends M105 commands and Transmit should blink shortly after each command; I'd expect neither of those are true, because it looks like the PC isn't sending anything.

Given that it's WIndows 7, anything is possible. I'd delete & reinstall the USB driver, but I admit to not doing Windows for many years: it's time for someone who knows more about all that to chime in!

[b8smat]

I know that both Rx and Tx work because if I remove the SD card, I don't get the last message that says the SD card is ok (it says it failed instead)

But after that, if I send an M105 command, I only see the Rx LED flash once. I never see the Tx LED flash ever again. (Which is consistent with what I see in Pronterface)

It seems like the firmware has crashed after the init sequence and fails to ever respond again.

I don't think it is anything the PC end, I have tried three different PCs and two different printer controllers (Pronterface and Cura) and two different USB cables. No change.

I checked the thermistors on both hotends, they both read about 93KOhms.

[ednisley]

Plenty of new info there: excellent debugging!

Sounds very much like you're right about the problem being in the firmware, but ... what's new & different? You haven't changed the firmware and AFAICT there aren't any "don't echo" flags to be turned on, so Something Bad has happened inside.

If you're using a recent Pronterface, try Settings -> Debug Communications to dump /everything/ from the initial Reset (poke the Reset button to force one). I doubt that will show anything different from you already know, but it's certainly worth rummaging in the debris field.

Other than re-flashing the firmware, I have no further suggestions. You've got a nasty one! [sigh]

[b8smat]

You're right, it doesn't show anything useful with debug G-code enabled.

AFAIK nothing has changed since the previous print. Although having said that, before this happened we had just hit (what I've been assuming is a completely unrelated problem) of very poor prints. As if the feed rate is wrong. (It can't have been wrong because it started halfway through an otherwise perfect print.)

This picture is of part of the failed print that broke off the good part...

[ednisley]

what I've been assuming is a completely unrelated problem

Verily it is written: Hell hath no fury like that of an unjustified assumption.

As if the feed rate is wrong

The M92 values look just fine, so a Mysterious Force hasn't stepped on that part of the EEPROM.

Have you verified that the minuscule set screw locking the extruder gear to the motor shaft hasn't worked loose? I drew a line across the gear and shaft to make any misalignment obvious:



Has the pinion gear inside the extruder gearbox gone bad? Verifying that requires taking the planetary drive apart, but it's not particularly onerous. This thread has pix and suggestions:
viewtopic.php?f=7&t=1930#p8819

That doesn't address the lack of response from the firmware, but perhaps it explains one part of the puzzle.