Dumbest question ever? Maybe

jt001

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The traces you see on top of a motherboard, are they actually exposed and conductive? Or are they coated with something? It seems like it would be the latter, but I've heard of a lot of people shorting out their boards with the standoffs accidentally in the wrong place and such.
 

albenza

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LOL, thats an interesting question.. the guy asking if the tiny hole in the top corner of the P4 processor had any meaning to it springs in mind. I believe it was agreed that it was a production thingy making it easier to assembly.

I would guess that they are in fact exposed and conductive as you would have to be seriously outta luck to accidentally short circuit it. Just a wild guess implementing a bit logic and manufactures need to save money to deliver cheap components though, I really have no idea.
 

fantastapotamus

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I've always assumed that they were exposed, but I wouldn't worry about shorting the traces as much as I would worry about shorting pins or solder points. The only time I've ever actually shorted out a motherboard was when I connected the wrong pins and I got to see blue sparks shoot through one of the IDE headers. The board still worked though.
 

cpburns

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:p i've shorted out a few motherboards before, but never from handling them or anything. one of them, my brother had enough static electricity built up to power NYC for a day, so when he picked up my Pentium1 tower, it actually fried the IDE controller. nothing else, just the IDE controller :(

the other one, well, the power supply blew up and sent a helluva shock to the mobo, causing it to catch on fire. that's when i learned to buy GOOD power supplies (this was 4 years ago :))

as far as the traces being exposed, i suppose i've always figured it didn't matter because all the wires that hang against my board are insulated. and if they're not, i replace them. the standoffs hitting the mobo problem, well, if a metal standoff hit me, it'd probably dig in too and cause some damage, coating or not. my buddy went frantic because he didnt remove the extra standoffs and one scraped a few resistors off the back of the board, killing it. he had to deliver the system to the client in 5 days.
 

jt001

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Well, the reason I ask is I'm going to be volt modding a motherboard, and I'm worried if some stray solder gets on one of the traces if it's gonna fry it. It's a cheapo board that I've been wanting to replace for a while anyway, so if I fry it I guess it won't be the end of the world really.
 

altazi

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What looks like exposed copper is covered with a VERY THIN layer of soldermask film. The traces are not exposed, and if you splash a bit of solder on them, it should scrape right off with a fingernail (don't use anything else, or you could damage it). This soldermask material is NOT mechanically strong, nor is it very thick. When mounting the motherboard with metal standoffs, if the standoff or the screw touches the wrong copper trace area, the mechanical force of screwing it down can pierce or scrape off the soldermask, resulting in a short-circuit. Generally, there is a small metallic ring with a thin layer of solder on it around the screw hole. It is OK for this to touch the standoff or screw head, but nothing else.

If the copper traces were exposed, the copper would tarnish rapidly, unless it was plated with a passivator layer. This would cost extra, and serve no purpose - you can bet there isn't a spare cent left over in the motherboard.

Regards,

Altazi
 

Seikent

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From what I remember, the traces that are lightly covered, but the problem is that the electronic components are still exposed, so you shouldn't touch anything because of static (-> short-circuit). And traces are still fragile.
 

KyleSTL

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Typically PCBs have a very thin layer of electical insulation on them (it typically results in the overall color you see when looking at a motherboard). I work at an electrical insulation plant and know this from first hand experience.
 

4745454b

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There is a thin film over the wires. It can break if scratched hard enough, or if you screw a motherboard down with an extra stand off.

The hole in the P4s would be for the same reason there is a hole in harddrives. Its a vent hole so that as the device heats up, the change in air pressure can/will happen.
 

altazi

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I watched a surgeon slip with his screwdriver once,
and right before our eyes that motherboard melted
some solder connections where the screwdriver tip
hit a few conductors, after a tiny flash of light.

He had forgotten to turn OFF the PSU switch,
and some capacitors discharged!

That was the end of that motherboard.
Better he killed a mobo than some poor Joe! Shoulda gotten an engineer to do the job!

Altazi
 

martyjs

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I had a customer who had bought a case with Power supply from us and complained the the power supply kept blowing up his Motherboard (was bought from else where). I opened the case and found he had used all the spacers except 1.
The top left hand corner of the motherboard was bolted strait to the chassis :eek: . Guess what? fried Motherboard. :pt1cable:
No replacement for either motherboard or power supply for him!!