Build version: edge-ed25d57, Build date: Oct 17 2015 22:04:52, MCU: LPC1769, System Clock: 120MHz
Win 7 64
Pronterface 2014.08.01
Test file G code generated by slic3r v1.1.7
Geomagic Design Version:[ PRODUCTVERSION 15,0,0,15072 ] 64-bit
Auto mount turned off, USB connection to printer
CPU gets VERY hot ( burn your fingers, guesstimate at over 100 degrees celsius).
Printer just stops, can not communicate with board, need to power down and reboot to get coms again
Imported from wikidot
Hey.
Does the MCU get hot right as you plug the board in, or does something specific cause this ?
What do the LEDs on the board show ?
Did your board work then stop working, or has it always done this ?
Starting up from cold (more than 2hrs off) 15 to 20 seconds MCU is to hot to keep finger on (comparing to heated bed touch test, it would be over 60C in 20 seconds).
Going from memory 2nd led is off, all others are on but static when board freezes.
Only got board setup to print today…
One thing I should have mentioned was that I fried Q8, had a hotend fan connected to pin 2.4 (12v 100mA). turn fan on (M40?) and magic smoke. Checked polarity of fan and it was correct, At this point, not sure what caused that to happen (diode was fitted to 2.4 pin). This was yesterday, so may have damaged board 
Board prints fine for approx 5 minutes then freezes (gets 2.5 mm into a 28 mm x 15 mm print with an 8 mm hole in the center)
print quality is excellent considering that there has been no tuning what so ever (4 attempts at the same print, and yes I redid the slicing and the stl export to try and filter out possible Gcode issues)
Can I see pictures of your board please ?
Cheers.
I would love to send photos, however, Karma strikes again
If I have done it right these are the links to the photos
In the first photo (275) the dangling plug is the lead to the fan (red+) and the damage to Q8. The other wire set to the left is for an LED light (which works fine). I have tried the fan since straight off the power supply and it works fine, all that has been done since then is unplug the fan
The blue wire paired with VBB+ is for the heated bed (220w) it is wired negative switched via a relay but will change that to positive switched (a little bit safer).
I have run all endstop wires through the harness so I can add the max endstops in later if I want without opening the harness (at the moment the unused endstop wires are individually insulated but floating, not sure if that will cause problems or not). Stepper wires are shielded (not high quality shielding, alu foil inside outer insulation sheath) to prevent interference with endstops.
Everything is mounted on a poly carbonate sheet.
[http://www.dropbox.com/s/ox0w2giek15hvw8/IMG_0275.JPG?dl=0]
[http://www.dropbox.com/s/14m8wg7zj8fe6cj/IMG_0276.JPG?dl=0]
[http://www.dropbox.com/s/wgb3mvlrix58j5i/IMG_0277.JPG?dl=0]
If you edit the links you should be able to get the images
This looks like something extremely violent happened to your mosfet, and it most probably damaged the microcontroller too.
Any idea what it could be ? I see nothing obviously wrong with the wiring.
100mA sounds like a lot for a fan, but if you had the diodes it shouldn’t have been capable of causing this …
Using Pronterface over ethernet I get the either one of the following error after a few minutes (1-2) printing
[ERROR] Can’t write to printer (disconnected ?):
Traceback (most recent call last):
File “printrun\printcore.pyc”, line 608, in _send
File “socket.pyc”, line 324, in write
File “socket.pyc”, line 303, in flush
timeout: timed out
[ERROR] Can’t write to printer (disconnected?) (Socket error 10054): An existing connection was forcibly closed by the remote host
under a usb connection it was just freezing
Okay, I ordered a new board , which has now arrived. I have 3 2 hour plus prints without issues.
Initially I did not connect the fan, and when I did, it was via a relay. It appears to be working fine.
Question now is,what to do with the old board. I would love to know what caused the magic smoke to get out (was it something I did or a fault on the board)
Do you want the old board back to inspect?
Hey.
If we see other similar problems happen to other people I’ll maybe ask you to send the board back, but at the moment as this is an isolated incident, do not bother to send it back. Just keep it somewhere in case we ever need it.
Glad to see everything is working now.
Cheers.
Damn 
I was hoping you would say “Yeah send it back and we will rebate the cost of the replacement”, oh well, I’ll see if I have better luck with Lotto
Hey.
I’m sorry, but actually debugging and/or fixing a board takes much more time/money than it takes to make a new board … so we don’t do it unless it’s really important ( for example if we suspect there could be a problem with the board design, which is not the case here ).
Cheers.
As the saying goes, “If you don’t ask, the answer is always NO”.
Sure it would be nice to get a replacement board, so would winning lotto
