Hot end port not working

[texsc98]

So I'm thinking that I fried some part of the RAMBo... I have control of all the motors through Repetier, and can heat up the bed, but the hot end temperature will not heat up. I confirmed that the hot end is functional by hooking it up to the bed output from the RAMBo and it started heating up. It seems that some component in the power distribution to the HEATER_0_PIN & HEATER_1_PIN on the board has been fried, but I'm no electronics board diagnostic expert so looking to the community to find out what I can meter out to determine the cause of the failure to replace it.


I'm using Polygonhell's firmware, I made my own repository though to keep track of changes I've made myself... Mine can be found here: https://github.com/afloyd/repetier-firm ... evelopment


Things I've tried so far:

1) Moved the hot end output plug ("HEAT 0" on RAMBo) to the bed output plug ("HEAT 2-BED") and turned on the bed temp to make sure the hot end temperature went up, and it registered in Repetier with increasing temperature

2) Since I confirmed the hot end was in fact working from a hardware standpoint, I tried re-mapping the pins in the firmware to the second extruder position by changing...
in configuration.h:
changed line 260
#define EXT0_EXTRUDER_COOLER_PIN 7
to
#define EXT0_EXTRUDER_COOLER_PIN -1

in pins.h
changed line 1089
#define HEATER_0_PIN 9
to
#define HEATER_0_PIN 7

Then moved the hot end plug to "HEAT 1" output on the RAMBo. Set the hot end temp to 200 and the temp didn't change.

Anyone have some ideas on what component could be fried, where it's at/etc... Or what steps to take to possibly track down which one it is?


My RAMBo picture gallery: https://plus.google.com/photos/10915024 ... oJDRh-izWw

[img]https://lh4.googleusercontent.com/-D3J- ... CN9549.JPG[/img]

[img]https://lh4.googleusercontent.com/-R79b ... CN9550.JPG[/img]

[img]https://lh3.googleusercontent.com/-IJBm ... CN9551.JPG[/img]

[img]https://lh6.googleusercontent.com/-IhEB ... CN9552.JPG[/img]

[img]https://lh5.googleusercontent.com/-Iy6c ... CN9553.JPG[/img]

[USMCPelto]

I had a similar issue. For some reason, if I set the fan to turn on and turn on heat to the hot end, then and only then will it get hot. I don't actually have any fans but for some reason this seems to work. I just add M106 to the start of my G-code to enable the fan.

[texsc98]

I had a similar issue. For some reason, if I set the fan to turn on and turn on heat to the hot end, then and only then will it get hot. I don't actually have any fans but for some reason this seems to work. I just add M106 to the start of my G-code to enable the fan.

That's definitely strange indeed! I've never had to do that... Might want to start a separate thread and see if someone can help with the issue. Sounds like maybe a firmware pin mapping issue or something

[texsc98]

So the problem has been located... A burnt out fuse! I emailed seemecnc support and John came back with an answer lightening fast! I didn't even realize there were 2 additional fuses to the one large blade style fuse in there, so I was pretty sure that's what the problem was. Here's a pic showing the fuses and what I think they relate to. In the pic the motors & logic fuse is removed, the other one was actually the burnt out one in my case. I just had pulled them each out to test them both. I also included the fuse part number I got from ultimachine https://ultimachine.com/content/fuse-0448005mr ($1). And a link to a ever so slightly cheaper one from Mouser electronics... http://www.mouser.com/Search/ProductDet ... 0448005.MR ($0.72). I went ahead and ordered 3 just in case I need one in the future, since they were so cheap

[img]https://lh3.googleusercontent.com/-qFKU ... /photo.jpg[/img]

I did rig up a test to make sure that it was just the fuse was bad using a similar fuse, a glass tube style fast-acting 125V 5A from Radio Shack. I just soldered some wire to each end of the glass tube fuse, and afixed the other ends of the wires to some leftover plastic from previous prints that I was able to trim to the same size as the fuse. Sometimes it's nice to have a lot of test prints lying around, not the first time those have come in handy! After putting that fuse inline the heater was back to working normally

And here's a close-up of the fuse that tested bad... No visual indications, must be pulled from the circuit and checked with a meter for continuity across the terminals
[img]https://lh3.googleusercontent.com/-GeQq ... CN9563.JPG[/img]