Hi, x0x #285 here (slacking a bit on construction)
I've gotten through a bit of my x0xb0x and while the power supply/io board was still pretty uncluttered, I decided to go ahead and do the dreaded IC25. Thank god for my friend loaning me his jeweler's lens!!
Anyhow, the whole thing went great and all the pins had good connections, but I had a bit of extra solder dangling from one of the corner leads. Since the whole thing was so perfect, I wanted to eliminate this (it was kinda close to the next pin in)
In an all too common "fix a minor problem, create a disaster", I had the solder pad for this corner pin come completely off the board. Ugh!
Now, it's not a huge deal for me to hack a wire between this corner pin and where it's going. But, I started to look at it, and I asked myself.. is this pin even going /anywhere/?? I don't think it is!
if you've got the chip oriented with the 'o' in the upper left, this pin is on the left side, top pin. There's no trace leading from the pad. I looked on the opposite side of the board, didn't see anything. I also held it up to light and couldn't see anything. However, I have no way to be certain.
Could anybody verify this for me, and/or direct me to a schematic where I could find this out? If this ends up being the case, it looked like there were a few pins that weren't being used (maybe 7 or 8). It could be worth noting to beginners that these can be safely ignored (if that's even the case)
Thanks for your time,
Robert
oops!! are all pins on IC25 important? :)
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maxtim
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I don't have my x0xb0x open in front of me at the moment, but can definitely say that if you see no traces leading to that pad on the top or bottom of the PCB, then it is indeed an unused IC pin and you need not worry. This is a 2 layer board, top and bottom, no internal routing.
The x0xb0x's PCB is great quality. I like the layout of the traces on this board. I think is was done the old-school way, using tape and donuts. I like the way the analog section is all rounded and organic, while the digital section is all right angles. It's a nice piece of art on its own. I have been planning to cut the bottom of the platic case and insert a plexyglass window and light to show off the board and other guts. I wish I could get a set of clear face and backplates made too (like Ladyada's prototypes).
Where can I find the time
PS: It is usually the unattatched pads that lift
For correct soldering technique it is important to note that no downward pressure on the tip of the soldering iron is required for heat transfer. It only takes a couple of seconds and a little push and those pads will let-go.
Cheers
The x0xb0x's PCB is great quality. I like the layout of the traces on this board. I think is was done the old-school way, using tape and donuts. I like the way the analog section is all rounded and organic, while the digital section is all right angles. It's a nice piece of art on its own. I have been planning to cut the bottom of the platic case and insert a plexyglass window and light to show off the board and other guts. I wish I could get a set of clear face and backplates made too (like Ladyada's prototypes).
Where can I find the time
PS: It is usually the unattatched pads that lift
For correct soldering technique it is important to note that no downward pressure on the tip of the soldering iron is required for heat transfer. It only takes a couple of seconds and a little push and those pads will let-go.
Cheers
Please be positive and constructive with your questions and comments.