Spare core parts & not enough & possibly screwed board

[MEEF]

Nearly finished soldering my first core module & there a few parts i cant work out what to do with. Ive got a red rectangle component (dunno what it is) which i presume is C6 on the schematic, that right?

Also i have two capacitors (i think  ???, yellow with 104 written on) but seems like there's nowhere to put them, after the C6 holes there is only the two under the PIC holder thing where i think the crystal goes, i'll come back to that, and then two on the top right hand corner. Even if it goes there i will still have a spare one (got a pack from Mike's shop).

And the crystal, im confused about this. On these pages it says it goes on the metal side of the board but on SmashTV's map it shows as going on the top.

Now the bad bit, I had to expand the holes of the trimpot (P2) but i was a bit heavy handed & managed to split the board slightly so the tracks werent meeting. I tried to push it back in & soldered the part in over the top, making sure it was making the connection between the broken tracks but my question is have i messed it up completely?

[Jidis]

Meef,

Small cap numbering is weird, but you'll see a lot of the same values, so you eventually get familiar with what "number" is what. I think the values are in picofarads (.000,000,000,000). The first two are the significant ones, and that third one is the number of "zeros" on the end. So, a 104 is 10, with 4 zero's or .000,000,100,000. The decrementing values to the right of the decimal are milli, micro, nano, pico or m,u,n,p (the groups of three zero's). Sometimes you also see ones with just a 2 digit number or something, maybe with a letter. I think they're all in pico's.

I'm looking at a print of the Core schematic pdf here, along with that construction page at uCApps. Looks like the cap numbering may be different (maybe from the two added bypass caps). C6 on my print is the 330nanofarad (334). Should be near the big-ass 2200uF cap (BTW- the electrolytic's are usually the large values, like microfarads, and have the actual values printed on them, along with their polarity). Looks like the 100nF's are the two small bypass caps which were added (under the core). I'm not sure if Smash or anyone has gotten them into permanent locations now though. There's also a 100nF(104) in parallel with the 10uF (electrolytic) near the regulator's output. On this pdf, it's C3, but on the site it's C4 and the 10uF beside it is C3. Make sure you get the negative sides of those two electrolytics tied to ground (should be the center pin on the 7805).

As Thorsten says, always go by the schematic. If you're getting wrong numbering on the caps, just use that and trace back to another PIC pin or something to make sure all the stuff's where it belongs. The 10uF and 2200uF are the only ones that have to go in a certain direction.

Yes, it looks like the crystal on a Core I've got here is inside the socket, and perpendicular to it. Top or bottom shouldn't matter, as long as it's got a solid connection and isn't touching any traces or pads. The short ones will fit under the PIC (my socket was shaved out a bit on the inside for it). Looks like the taller can in the uCApps pictures is underneath. I'd stick electrical tape or some insulator under, or around the crystal if you do that.

You may have been given extra parts the kit, but make certain the ones in the schematic are all present and accounted for on the board (along with the two 100nF bypassers), and the values and polarity are right. Don't leave any empty holes. If there's any part missing, you should be able to find one on a broken something somewhere around the house and desolder it. (No offense to the kit dealers. I know you guys are extra careful ;))

I'd check all the traces extra close, if you think you may have bent that PCB. Stick a multimeter, set to "continuity" on both sides of the "suspect" area and make sure it's not cracked (not sure if you'd have to bend the board again to really check that). If you need to fix it, or want to be safe, you can either bring a long, uncut leg of your component, all the way through the hole, and neatly fold it under the board, in the path of the trace (if it reaches), and solder it down. You can also take a piece of small solid copper wire (maybe tinned with solder), and bend it into the shape of an "L", with the short half being long enough to bridge the trace. Then you can use the long leg to hold it onto the board where you want it, and tack it down with some solder (don't get burned). I use one of those two armed alligator clip doohickeys with the heavy base to hold it, but you could also tape it to the board, and bend it into a shape to make contact. After it's done, you can snip off the long part with some toenail clippers to clean it up.

Sorry if you already knew any of that (looks like you may have done the leg-bridge method).

Hope something in there helps!  :)

George 

[NorthernLightX]

Hi MEEF,

Nearly finished soldering my first core module & there a few parts i cant work out what to do with. Ive got a red rectangle component (dunno what it is) which i presume is C6 on the schematic, that right?

Yes, the C6 can be red and rectangular, and is a ceramic capacitor. You might read 0,33 and perhaps also WIMA on it (it says so on mine, which are from Reichelt btw.)

Also i have two capacitors (i think  ???, yellow with 104 written on) but seems like there's nowhere to put them, after the C6 holes there is only the two under the PIC holder thing where i think the crystal goes, i'll come back to that, and then two on the top right hand corner. Even if it goes there i will still have a spare one (got a pack from Mike's shop).

Those 104's are 100nF ceramic capacitors, and are for decoupling the PIC power input. They go on the bottom of the board, you'll have to "surface mount" them, it's tricky but certainly doable. Look at the 5th picture of the Core module soldering guide on uCApps.de, you can see them there. They go over the broader tracks.

And the crystal, im confused about this. On these pages it says it goes on the metal side of the board but on SmashTV's map it shows as going on the top.

Smash sold a smaller type crystal which fits under the PIC socket. In the new design it's even beside the socket, but Mike sells the original designs so you can not use Smash's excellent web page layout thingy, unfortunately.

I think Mike still sells the bigger crystal, which you'll have to mount on the bottom, because it's too big to fit under the pic. Look at the soldering guide on uCApps.de, you'll find it there.

Now the bad bit, I had to expand the holes of the trimpot (P2) but i was a bit heavy handed & managed to split the board slightly so the tracks werent meeting. I tried to push it back in & soldered the part in over the top, making sure it was making the connection between the broken tracks but my question is have i messed it up completely?

Sounds bad, but only a picture can tell. If you make sure there's contact over split tracks I don't think there's much damage, but if your board is actually split in some way, I hope it doesn't break in 2 when pushing the PIC in... :o

So post a picture of how it looks now (photograph or something, you have to host the picture somewhere first though) so we can judge it right.

Cheers,  Alex.

[NorthernLightX]

A long ass post while I was typing mine

Quickly posting someting while I'm writing my nice little story eh? I'll remember that young man!  ;)

[Jidis]

The more the merrier!  ;D  I was just waking up, and needed something to do while I drank all my coffee.

I'm not up on what's usually coming in the kits anyway, so the the details on the xtal and the caps might help. :)

BTW- If anybody "in the know"  should read this:

What exactly are the correct "styles" of smaller caps for different applications, or is there an "order" to some of them quality-wise? I've got a heck of a selection here on digital cards and boards, as well as some new ones (mostly regular "brown" ceramics).

Also, is there any accurate means of guessing  what a given cap is made of, by the package style (beyond the brown ceramic disc ones)?

A good link with pictures would suffice (or save some typing), but I've still got the question of which ones for what (analog or digital filtering,etc.)?

Lastly, what in the Sam Hell is this big black box I've had here for all this time? I think it came in a DigiKey order, long ago, when I made a "Greg" board. It says it's a .82uF UV "box type", and it's part number is P4646-ND. It was in the parts list at uCApps (or it was back then). 

[MEEF]

Thank you so much for your replies, im really grateful! And no i didnt know much of all that so thanks for educating me, i know surprisingly little about this (or perhaps not so surprisingly from the mistakes ive made!) so any spoon feeding is very welcome  ;D

Gonna have to absorb all this & check what ive already done. I will get back to you if there's something im not clear on.

I will hopefully post a picture soon, although to be honest im reluctant to as i feel my soldering is quite embarrassingly bad. Thnaks again though, you've really helped me clear a few things up.

[smashtv]

I will hopefully post a picture soon, although to be honest im reluctant to as i feel my soldering is quite embarrassingly bad.

-Never- worry about this.....Even though we might poke fun at you a bit, know that every last one of us here has boards around that look bad.....Some of my stuff looks like it was soldered in the back of moving truck, by a drunken monkey, with another drunken monkey behind the wheel.....  ;D

Best

Smash