why did my Printer melt?

[jay_s_uk]

If they're on from start up then the mosfet has failed due to more than likely a short in the wiring.
Any pictures of the melted hot end?

[Phaedrux]

Which board? Firmware?

[Killernoy]

@jay_s_uk it is disassembled right now but the Heater blocks are melted the ´last temp i saw before shut down were around 650 C

[Killernoy]

@Phaedrux Duet2 Wifi with duex5 and RRF3

[Killernoy]

One of the Heatblocks the thermistor is still in it but I had to rip the cable of because plastic was molten around it

[Phaedrux]

@Killernoy said in why did my Printer melt?:

RRF3

which version specifically?

[Phaedrux]

@Killernoy said in why did my Printer melt?:

every heater output is set to 100% at startup?

Every heater was on full power at startup?

[Killernoy]

This post is deleted!

[Killernoy]

@Phaedrux said in why did my Printer melt?:

@Killernoy said in why did my Printer melt?:

every heater output is set to 100% at startup?

Every heater was on full power at startup?

Yes

[Killernoy]

@Phaedrux said in why did my Printer melt?:

@Killernoy said in why did my Printer melt?:

every heater output is set to 100% at startup?

Every heater was on full power at startup?

3.0 beta12 2019-11-02b1

[Phaedrux]

Is it still doing it? Can you get an M122 diagnostic report from it?

[Killernoy]

@Killernoy said in why did my Printer melt?:

@Phaedrux said in why did my Printer melt?:

@Killernoy said in why did my Printer melt?:

every heater output is set to 100% at startup?

Every heater was on full power at startup?

Yes

correction not every just Bed and E2 E3 and E6

[Killernoy]

@Phaedrux said in why did my Printer melt?:

Is it still doing it? Can you get an M122 diagnostic report from it?

Yes it is

=== Diagnostics ===
RepRapFirmware for Duet 2 WiFi/Ethernet version 3.0beta12 running on Duet WiFi 1.02 or later + DueX5
Board ID: 08DGM-95BLL-N65TJ-6J9F4-3S46L-1JWVL
Used output buffers: 1 of 24 (1 max)
=== RTOS ===
Static ram: 25812
Dynamic ram: 99608 of which 0 recycled
Exception stack ram used: 256
Never used ram: 5396
Tasks: NETWORK(ready,1448) HEAT(suspended,920) DUEX(suspended,160) MAIN(running,3652) IDLE(ready,200)
Owned mutexes:
=== Platform ===
Last reset 00:00:43 ago, cause: power up
Last software reset at 2019-12-17 16:50, reason: Unknown, spinning module Webserver, available RAM 4992 bytes (slot 2)
Software reset code 0x40b2 HFSR 0x00000000 CFSR 0x00000000 ICSR 0x0041f80f BFAR 0xe000ed38 SP 0x20001ec4 Task 0x5754454e
Stack: 0044f28f 00450e22 81000000 00000000 40740000 3edb6db7 b7b4d800 3331bb4c 40000000 3f317200 b5ddea0e 388aa908 41e2ece8 00000000 00000000 00000000 00000000 00000000 40400000 80000010 00449277 00000001 004067db
Error status: 0
Free file entries: 10
SD card 0 detected, interface speed: 20.0MBytes/sec
SD card longest block write time: 0.0ms, max retries 0
MCU temperature: min 24.9, current 29.1, max 29.4
Supply voltage: min 0.3, current 0.5, max 0.6, under voltage events: 0, over voltage events: 0, power good: no
Driver 0: ok, SG min/max not available
Driver 1: ok, SG min/max not available
Driver 2: ok, SG min/max not available
Driver 3: ok, SG min/max not available
Driver 4: ok, SG min/max not available
Driver 5: ok, SG min/max not available
Driver 6: ok, SG min/max not available
Driver 7: ok, SG min/max not available
Driver 8: ok, SG min/max not available
Driver 9: ok, SG min/max not available
Date/time: 1970-01-01 00:00:00
Cache data hit count 132068223
Slowest loop: 0.76ms; fastest: 0.07ms
I2C nak errors 0, send timeouts 0, receive timeouts 0, finishTimeouts 0, resets 0
=== Move ===
Hiccups: 0, FreeDm: 169, MinFreeDm: 169, MaxWait: 0ms
Bed compensation in use: none, comp offset 0.000
=== MainDDARing ===
Scheduled moves: 0, completed moves: 0, StepErrors: 0, LaErrors: 0, Underruns: 0, 0
=== AuxDDARing ===
Scheduled moves: 0, completed moves: 0, StepErrors: 0, LaErrors: 0, Underruns: 0, 0
=== Heat ===
Bed heaters = 0 -1 -1 -1, chamberHeaters = -1 -1
=== GCodes ===
Segments left: 0
Stack records: 1 allocated, 0 in use
Movement lock held by null
http is idle in state(s) 0
telnet is idle in state(s) 0
file is idle in state(s) 0
serial is ready with "m122" in state(s) 0
aux is idle in state(s) 0
daemon is idle in state(s) 0
queue is idle in state(s) 0
autopause is idle in state(s) 0
Code queue is empty.
=== Network ===
Slowest loop: 15.55ms; fastest: 0.00ms
Responder states: HTTP(0) HTTP(0) HTTP(0) HTTP(0) FTP(0) Telnet(0)
HTTP sessions: 0 of 8

• WiFi -
  Network state is running
  WiFi module is connected to access point
  Failed messages: pending 0, notready 0, noresp 0
  WiFi firmware version 1.23
  WiFi MAC address 2c:3a:e8:0a:f2:1b
  WiFi Vcc 3.41, reset reason Turned on by main processor
  WiFi flash size 4194304, free heap 26096
  WiFi IP address 192.168.178.77
  WiFi signal strength -72dBm, reconnections 0, sleep mode modem
  Socket states: 0 0 0 0 0 0 0 0
  ok

[dc42]

I'm sorry to hear of your misfortune. The only time I have heard of this happening before was when there was over-voltage on the +5V rail (due to a short to +12V or +24V) which resulted in failure of the mosfet driver chip. It's labelled U11 and it's close to the reset button and extruder heater mosfets. Does it look damaged?

Are you powering anything external to the Duet from the +5V supply? What fan voltage are you using?

[Killernoy]

@dc42 said in why did my Printer melt?:

I'm sorry to hear of your misfortune. The only time I have heard of this happening before was when there was over-voltage on the +5V rail (due to a short to +12V or +24V) which resulted in failure of the mosfet driver chip. It's labelled U11 and it's close to the reset button and extruder heater mosfets. Does it look damaged?

No it does not look damaged to me, but take a look for your self

Are you powering anything external to the Duet from the +5V supply?

The fans

What fan voltage are you using?

5V

[jay_s_uk]

U11 looks damaged to me. it has a hole in it

[Killernoy]

@jay_s_uk said in why did my Printer melt?:

U11 looks damaged to me. it has a hole in it

I don´t know if I´m right but to me it looks like a Texas Instruments Logo

[dc42]

U11 looks OK to me in that photo, but the symptom suggests to me that it has failed.

As you are running 5V fans. I suggest you check very carefully that there is no possibility of a short between the fan wires and the hot end heater wires. We've seen users damage Duets before because of such shorts. That's why I argued (successfully) for us not to provide a jumper to select 5V fans on Duet 3 (OTOH, Duet 3 has a 12V regulator on board so that 12V fans can be used).

Some fans and other devices (especially servos) pump power into the supply rail when they turn off, although in the case of small brushless fans, the smoothing capacitors on the supply rail should take care of that without excessive over-voltage.

[Phaedrux]

This post is deleted!

[Killernoy]

@dc42 I checked with a multimeter on continuity-mode one probe at the fan voltage select the other on the Heater out put screws one at a time. No short was found but strangely the 3V+ LED lit up