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Topic: No 12v from board

I sliced ribbon the usb connection  on the board on my SD2  as directed in the post to keep my printer from stopping mid print. Restarted the printer and it sent the extruder  temp to 279.  Tried stopping it with the software but nothing would  so i unplugged it.
Now when i plug it in i have no 12 volts to anything except the led lights.  It doesn't clunk anymore when I connect  to the printer using the R/H.

Any ideals?

Whats a good replacement board?

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Re: No 12v from board

Where was the direction from?

Do you have a pic of what you did?

If you are replacing the board, easiest swap would be RAMPS or maybe a azteeg.

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Re: No 12v from board

These are the directions http://forums.reprap.org/read.php?158,1 … msg-123850
http://forums.reprap.org/file.php?158,f … no5_01.png
I cut with a razor knife.

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Re: No 12v from board

I have also modified my Sanguinololu like in that thread but I went for option 2. No issues thus far for me.

It's unlikely that the extruder actually got to 279, so maybe there was a short with the thermistor that gave the bogus reading. In that case, the analog to digital converter on the microcontroller is probably fried.

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Re: No 12v from board

it was hot and smelled like melting plastic.

I guess I will solder and try option 2

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Re: No 12v from board

Hard to workout what you mean by:

Restarted the printer and it sent the extruder  temp to 279

Were you supervising the printer at the time? Would have taken a while for it to reach this high.

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Re: No 12v from board

I was there.  It heated up pretty fast.  Just lucky the metal  of the hot end didn't drop out.  I guess the helicoil helped.

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Re: No 12v from board

The missing 12v was a bad 110v cord to the power supply.
I did find a loose wire to the thermistor
soldered one cut and cut another trace on the board. 

Now I get 
16:30:54.200 : N1292 G1 X111.452 Y76.562 E7.07884 *76
16:30:54.219 : Printer stopped due to errors. Fix the error and use M999 to restart. (Temperature is reset. Set it after restarting)
16:30:54.220 : N1293 G1 X32.975 Y76.562 E10.10863 *76
16:30:54.239 : Printer stopped due to errors. Fix the error and use M999 to restart. (Temperature is reset. Set it after restarting)
16:30:54.240 : N1294 G1 X32.599 Y76.53 E10.1232 *76
16:30:54.259 : Printer stopped due to errors. Fix the error and use M999 to restart. (Temperature is reset. Set it after restarting)
16:30:54.260 : N1295 G1 X32.069 Y76.384 E10.14443 *74
16:30:54.280 : Printer stopped due to errors. Fix the error and use M999 to restart. (Temperature is reset. Set it after restarting)
16:30:54.281 : N1296 G1 X31.745 Y76.226 E10.15837 *68
16:30:54.300 : Printer stopped due to errors. Fix the error and use M999 to restart. (Temperature is reset. Set it after restarting)

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Re: No 12v from board

I usually see that if I unplug the extruder thermistor.

It does it to prevent an overheat. What temp is it reading?

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Re: No 12v from board

lawsy wrote:

Hard to workout what you mean by:

Restarted the printer and it sent the extruder  temp to 279

Were you supervising the printer at the time? Would have taken a while for it to reach this high.

It actually heats up faster than you expect. This sounds similar to what happened to me. Except, I thought it was just reading wrong. I didn't get mine to cool down until it was too late And it melted the peek.

SD3 w/ mods:
Glass bed with QU-BD heat pad upgrade, threadless ballscrew w/ 8mm smooth rod, spectra line belt replacement, lawsy MK5 extruder, Lawsy replacement carriage, E3D hotend, Ramps 1.4 w/ reprap discount controller, DRV8825 drivers, 12v 30A PS, Acrylic case, Overkill Y-idlers, Filament alarm, Extruder fan + more.