Hardcopy help!!?

hi all

i'm converting a project i have to a more permanent version - and using the hardcopy to do so. i just soldered the basic components of the board together, but am not seeing the power LED light. i'm rusty on this stuff so i'm looking for help with a couple of things:

1) i have a male dc power jack that i've wired to the ground and VIN pins on the board, but can't seem to find specs on the jack to be sure which is ground and which is power. after much searching - i tried it both ways, but neither lights the LED and one heats up the voltage regulator a LOT (obviously bad).

2) how best to debug the connections on the board and see where the disconnect is? i assume the multimeter is key - but any technique suggestions would be a huge help.

and of course anyone that has put the hardcopy together and used it - i'd love your input.

thank you! claudia

For 1 use your digital multi meter, put one probe in the connector the other one on the outside. Depending on how you connect you should see a possitive or negative voltage. (also most wallwarts will tell what is what on the housing or on a sticker)

for 2 use continuity test from you multimeter and look for short circuit and the likes.


Just saw the capacitors might be polarised (have a plus and minus lead)

thank you!

i think i figured out the power and am just now trying to test for connectivity - but am not quite sure i'm testing properly. i'm looking at the lines that connect the pieces of hardware on the underside of the hardcopy, and following those. the capacitor's being polarized would definitley be an issue - there's not mention of that in the hardcopy instructions. do you have any more info on that? thanks so much for the help! i'm still stuck... :(

i just found this note on an unrelated topic:

Be sure you get the 220Ohm, 10k Ohm resistors, 22pF, and 0.1uF capacitors in the correct places. They are not polarized. so - i guess that's not the issue...

i just found this note on an unrelated topic:

Be sure you get the 220Ohm, 10k Ohm resistors, 22pF, and 0.1uF capacitors in the correct places. They are not polarized. so - i guess that's not the issue...

Also check if some of your solder has shorts to other point. e.g check if some things make contact which shouldn't make contact.

Another thing make sure that led is the right way around.

thanks for all your help - the creator of the board is assisting me now. will keep you posted.

quick question - do you recommend solid or stranded wire when soldering to a pcb in general? it seems the solid can snap - but stranded is messier?

If you expect any flexing, use stranded (like battery snaps or such); otherwise solid can be ok. It is really a judgement call. Stranded is also good if you plan to fiddle with the board and such (ie, removing it for testing or upgrades, or moving it around, etc).

Something also to keep in mind: if you have more than a few wires running to the same place (like say, for instance, you have a custom PCB holding the Arduino uC, and a separate board with display/input elements on it), consider using a piece of ribbon cable (an old PC floppy or IDE cable works great after you cut the connectors off; you can easily peel off however many strands you need).

Finally, to make things easier: twist and tin those stranded ends - strip off the insulation, twist the ends tightly with your fingers, then heat up a small blob of solder on your iron (a flat tip works great for this), bring it near the end, then quickly dip the end while applying a bit more solder on the top - it shouldn't take more than a second to do once you get the hang of it. The twisted strand will act like solder braid and suck the solder into it, then when you remove your iron, it will solidfy, and you will have an end that is easy to solder directly onto pads, or via thru-holes on your PCB (or, if you are planning on moving it around a bit, use IDC connectors).

Hope this helps!

then heat up a small blob of solder on your iron


get a cheap pair of helping hands, hold the cable with that applay iron then solder, that way you get flux making a solid pin (good enough for breadboards)

and getting into the habit of “blob on the tip” is a good way to gather bad soldering skills, without flux you can burn the crap out of anything you want all day and solder wont stick

There is only a small amount of flux in the solder.

In addition to making the 2 parts to be joined "cleaner" so the solder can make a better joint, the flux acts as a wetting agent which breaks down the surface tension between the molten solder and the parts to be joined.

The BLOB approach needs to overcome the surface tension issue. (and for a big blob... it's the surface tension I'm talking about that makes solder blobs "round") A blob with high surface tension will fly off the tip or go where you "don't" want it to go faster than it will do what you want.

Many fluxes evaporate quickly under the heat of an iron... so adding extra flux to the joint prior to the "blob method" may be your best bet. I'm not saying to use that method... but if it just easier at this point... add some extra flux where you will be working.

yea the tiny amount in the solder will burn off before you even get half way to the part, course the tiny amount in the solder is more than plenty if proper soldering techniques are used

I just think its a bad idea suggesting this to someone new