Generation 3 electronics troubleshooting

Ok. I've got myself into a pickle with my gen 3 electronics. I've build them, but I think that I've made a mistake in my soldering or something, everything looks fine to me. Now comes the wierd thing...

I plug in my electronics bootloader into my motherboard, it works fine and uploads itself nice and properly. When I press reset now it does that nice double flash then flash that arduinos do (which tells me my bootloader is working fine) but no power LED lights up they never have. When I plug in my normal USB-Serial cable there is just nothing.

Then comes the really wierd thing. Because when I plug in my extruder board, I get the exact opposite problem. I plug my bootloader in and the power LED lights up fine (although the power light in my bootloader goes out and the computer thinks that I've disconnected it). but now because the bootloader has died, I can't upload anything to it.

Sorry if all this seems a bit vague, it's just driving me crazy right now. I know it's not a software problem, but I don't know enough about electronics to work out where it is that I've made the mistake in building.

If you want to test the motherboard without loading the official firmware, this should light up your power LED IF you have a power supply attached - the photo is pretty self-explanatory:

[forums.reprap.org]


As for the extruder board issue, if you are using something like the USBTinyISP [www.ladyada.net] make sure the power jumper is set correctly. I am still a little uncertain what you are asking here, is your bootloader hardware toast or do you just need to re-burn the chip?

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[www.binaryconstruct.com]

I can't burn the extruder chip at all. The bootloader isn't toast, but it does stop working when I plug it into the board. Basically, The Power light on the bootloader comes on when I plug the loader into my computer. Then when I plug the bootloader into the actual board, the power light on my bootloader goes out, but the extruders power light comes on. I'm thinking I wired something up wrong and am trying to work out what it is.

Plus the power light doesn't come on when I plug in my serial cable to any of my boards, even the one which I know has a bootloader installed properly.

Check for bridged pins on the ATmega chip, sometimes they can be really hard to see. [reprap.org] You might also want to double check the solder on all the parts (especially the Capacitors), to make sure it is shiny silver. If any of the solder paste is dull gray, touch a hot soldering iron to it until it turns shiny.

The motherboard in its current revision won't lite the power LED unless you use the jumper with a power supply or load the gen3 reprap firmware to it (also with a power supply plugged in).

Edited 1 time(s). Last edit at 05/11/2009 10:11PM by Jeff.

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[www.binaryconstruct.com]