Sanguinololu Hot end problem!!

Hi guys firstly what a great site! It has helped me endlessly my Prusa Mendel build. I have a problem and wonder if you guys can help me out?

I have got to the stage where i have built Prusa and electronics, the X Y Z and extruder move perfectly but i cannot get my hot end to heat up. Can someone please help me out or give me advice to fix this problem? I will give detail of what i have and what I’ve done.

Firstly have a Sanguinololu 1.1 that i converted to a 1.2 and have uploaded the latest version of sprinter to the ATmega. I hooked up a techzone tip that uses Nichrome wire to the 0v-12 pwr/tip of the Sanguinololu. The tip itself heats up when i connect it directly to a 5v psu. Also instead of the TC that comes with the tip i am using a 100k thermistor and that is connect directly to the E-therm connector of the Sanguinololu. When i open RepSnapper or Printrun i turn the heater on but nothing happens ant the thermistor feedsback a 0. I check the output voltage of the 0v-12 pwr/tip connector and i am getting 0v. Have i screwed something up during the build of the Sanguinololu or is there something in the firmware stopping the power going out of the 0v-12 pwr/tip connector?

I have been on this for days now and i may have missed something fundamental?

Any help would be much appreciated ><

Al

You will get a much faster reply if you join the conversation in the RepRap IRC [reprap.org]

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Charles Gantt.
Build blog [themakersworkbench.com] <---- my personal site
Build worklong [www.thebestcasescenario.com]

Thanks SCphotog,

I'm talking to the guys now

Al

No problem. I stayed away from the IRC for years and once I joined things were so much easier.

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Charles Gantt.
Build blog [themakersworkbench.com] <---- my personal site
Build worklong [www.thebestcasescenario.com]

In case someone reads this and has a similar problem, found out what was wrong. I had the capacitors c9 and c10 the wrong way around, this stopped the 100k thermistor from working which in turn stopped the hot end heating up. I was informed the software has "safety" code which stops the tip heating if there is an issue.

Thanks for everything guys

Regards
Al