So?
DUMB AS A FUCKING BOX OF ROCKS.
I take it you've "dabbled " in electronics as a hobby? Yes? Maybe made your own circuits? Yes?
Whooptie friggin doo.
Now go learn about multilayered PCBS - that's what industry commonly use. That's when one PCB has several layers of copper sandwidched together.
THis company here:
...does up to 24 layers on a single PCB.
Just because the tracks you CAN see go to the fuse, doesn't mean tracks you CAN'T see don't.
-- Conor If Pac-Man affected us as kids, we\'d all be running around in darkened rooms, munching magic pills and listening to repetitive electronic music.
I doubt it.
Not forgetting that you need to not only trace both sides at the same time. remembering those little holes are actually links from one side to another, but also find out whethere there are layers in the middle too.
-- Conor If Pac-Man affected us as kids, we\'d all be running around in darkened rooms, munching magic pills and listening to repetitive electronic music.
And he has had an answer. To provide flexibiity in the motherboard for the manufacturer to use it for more than one type of product.
-- Conor If Pac-Man affected us as kids, we\'d all be running around in darkened rooms, munching magic pills and listening to repetitive electronic music.
On Thu, 18 Aug 2005 21:01:03 +0100, Conor put finger to keyboard and composed:
What is it about the OP's post that you don't understand? He has stated that all the motherboard's IO functions are operational. This means that *all* devices are getting their power from the motherboard, despite several fuse locations being unpopulated, ie *open*. So the OP's question as to what function these missing fuses would have performed is a valid and logical one.
- Franc Zabkar
-- Please remove one \'s\' from my address when replying by email.
While that seems logical in a good design, what we have in these cases is "usually" a board layout that allows for the various fuses, but then later the fuses are not added (shaves a couple cents cost) but rather that fuse location has a jumper wire, or just traced over.
I agree, but still it's curious that this particular board has this setup. He and I have both noted many boards with the fuses there OR missing where they had used more obvious method of continuity of the 5V supply by merely bridging the pad(s) gap where a fuse could've gone.
Usually not, the 5V power plane does not extend that far and generally singular 5V traces are not put in middle layers for such ports. "Maybe" they did it, but if so this is first time I (or apparently LM&C) has seen it.
You would do to stop pretending you have vast knowledge and gain some ACTUAL hands-on experiece with motherboards. AT least then you'd have a slight hint at what's being discussed and the significance of it.
Instead you guess about it, because it has some passing similarity to some other electronics circuits? Well this isn't "some other" circuit.
Please take the hint that the problem is not our lack of understanding very basic circuit board concepts but yours in not realizing what is normally seen on motherboards.
Some grand (but simplistic) thought about multiple layers does not change the fact that no other boards that (we're) aware of, use inner layers for port power. I welcome anyone to come forward with examples of any boards that do.
Further, if this board had an inner layer suppling (5V), it would make the 5V traces, fuse pads on top completely worthless and just a waste of space to put on the board at all... yet there they are.
Never claimed otherwise. Now give us even one example of a board that does this so your theory is something more than a wild guess.
This is the reason. I used to work for a large Taiwanese motherboard company. If the board was being sold into a channel where there was no UL/CSA/TUV, etc. requirement for fusing the power going off the board, then the fuses were eliminated. Motherboards sold at retail are not going into systems that will ever need to be certified by a safety agency, so there is a savings of a few cents per board by eliminating the fuses.
There are other savings that are possible with boards that would never be used in systems that would go through agency approval. You can use cheaper PC board material. You can eliminate the double protection against charging the on-board lithium battery. IIRC, those were the only three things that the safety agencies looked at. For EMI, there were other items that could be eliminated.
It is probable that the motherboard company changed one of the inner layers of the board (the power layer) on the board in question, to eliminate the need for a jumper, or a copper trace, on the top or bottom layer. Installing a jumper, or cutting a trace, is as expensive as putting in a fuse.
Acually UL does NOT require fuses. You have the option of providing a keyboard and mouse where a short from power to ground, with the maximum current that the power supply can provide, will not result in an unsafe condition (excessive heat or fire). Never mind that the PC board trace would be destroyed long before the maximum current condition ever occured. Needless to say, it was easier to put in a fuse, and trying to argue with UL is like trying to teach calculus to a cat.
Conor, , the ineffectual, p*rn-ogling rat, and employee in charge of emptying cesspools, bickered:
Hello, coonertard. It looks like it's time for you to be slapped down a few pegs again.
-- Doug Grant wrote: > If you want to respond to my posts... then email me and > I will either allow you to do so or not.
Jumpster Jiver, , the bone-lazy, nameless dumbass, and bobbin turner, pined:
BWAHAHAHAHAHAHAHAHAH! You f****ng stupid cunt.
-- Doug Grant wrote: > If you want to respond to my posts... then email me and > I will either allow you to do so or not.
It's reasonably common to design a board to accomodate two or more styles of certain components so either can be used depending on which is most available/least expensive at the time of manufacture. For example one of the boards made where I work had pads in place for two different package styles of voltage regulator, the pads are wired in parallel but only one location is stuffed with the part.
Regardless of your level or lack of knowledge, your attitude certainly leaves much to be desired.
I had hands on experience of multilayered PCBs back in 1987 working as an engineer in the video games repair industry.
I have. More than you it would seem.
I know exactly what is normally seen. I also know that some functions have ended up being integrated into ICs themselves. As well as that, my background comes from an industry which routinely scrubbed numbers off chips and also misnumbered them to prevent piracy.
Why wouldn't they?
So they're there. SO FUCKING WHAT? I can show you 20 CB radios from one manufacturers, all based on the same board layout. On each model, the PCB is the same but the components differ with blanks being left for unused sections.
-- Conor If Pac-Man affected us as kids, we\'d all be running around in darkened rooms, munching magic pills and listening to repetitive electronic music.
Kony, despite two of us now saying the same thing, will claim he is right.
-- Conor If Pac-Man affected us as kids, we\'d all be running around in darkened rooms, munching magic pills and listening to repetitive electronic music.
I guess you're not that old?
-- Conor If Pac-Man affected us as kids, we\'d all be running around in darkened rooms, munching magic pills and listening to repetitive electronic music.
And the answer it seems from me reading this entire series of rants and logical converstaions is that the only function that would have served is to allow the board to be Certified for use in a safty controled enviroment. Otherwise there is probally no other function to the fuse.. there or not.. its all a matter of certification and that seems to be all, unless I see the 95% similar model with the fuses in place, no cert, and new features that the other didn't have due to a small change of 1 fuse... i dont think there would be a point to attempt to find out further.
------------------ Motherboards are like Orges, and Orges are like onions.. they both have layers and the both can make your head hurt really bad....
You offer a general theory on how it would be possible to do it. That theory is of course obvious (that is, "possible in theory so long as we only consider that detail) to anyone who knows about multi-layer boards, BUT you are ignoring a few things.
1) We have no, zero, evidence that _ANY_ motherboards do this. Do you carefully examine modern motherboards? I think not... LM&C, and I, do. "IF" this particular board uses an inner layer to connect to the 5V rail and/or 5VSB, this is the first evidence we have of it, evidence meaning an actual board that does so... or at least nobody has observed and/or mentioned it. 2) I continue to question the idea of implementation of the surface-mount jumpers or fuses as optional based on using one board layout for multiple featured (or zoned) products. It is questioned because to implement the fuse ever (else it would not be layed out on the board at all) the inner layer cannot be connected in that implementation. Therefore, when some boards used the fuse, they would have a more laborous modification needed, to rework the inner layer before fabbing the PCB rather than choosing which surface-mount pads to populate.You can't have it both ways, if the inner layer trace(s) suppy power then there is no purpose to surface-mount pads at all, they are a complete waste of space and never useable, UNLESS they reworked the inner layer every time. I don't think they do that, but again I'll welcome any real evidence of it rather than some theory that it "could be done" without consideration of whether it ever is.
There is still another possiblity, that the board can accomodate other I/O ports/features, that the missing fuses/jumpers do not actually serve to supply the ports that are implmented on this specimen of the board, nor do the ports on the board have inner layer traces, but that the ports on the board ALSO have surface-layer traces suppling power, yet another 5V supply line for them.
Good for you, now would you feel it's reasonable for anyone else to insist that they "know" for certain how one of those
1987 PCBs was designed based on their observation of a modern PC motherboard, when every single board you've ever seen from '87 was NOT like that "anyone" insists they are?Generaly theory that multiple layers can allow a trace not seen, is not evidence that this IS how and why LM&C observed what he did.
Again you fail to grasp the obvious... that you would have to actually examine modern motherboards to have any applicable evidence. A theory about what "could" be, is not the same thing as evidence of it actually being true.
No, you clearly have no clue about what is normally seen. Look on the motherboard in the system you're using RIGHT NOW. Dig a few dozen out of a closet and look at them. Look online at good pictures. Your "opinion" is worth little if it is not consistent with actual boards.
Would you agree than when the surface-layer's pads ARE populated with a fuse (or a jumper, inductor, 0-Ohm resistor, or trace closing the two fuse pads) that it would be pointless when there is also a parallel power trace in an underlying layer? Certainly anyone with as much circuit board experience as you claim would at least recongnize this basic electrical fact, that one cannot fuse one of two parallel supply lines and have the fuse be useful. Therefore there is no point to having surface-mount pads unless the inner layer is reworked.
Is this what you claim, that they redesign and remanufacture boards with a different inner layer every time? That would be quite the opposite of this "universal" board concept you claimed where they can use one board with ommision of some surface-mount components based on need.
For one, because they have them on the top layer. I've already mentioned the issues surrounding parallel lines and inner layer rework for supposed universal boards.
So you're not using evidence or any thorough evaluation of whether your idea is reasonable, merely making a passing comment about internal layers is just an educated guess... but not all that educated because you are not using ANY modern motherboards as examples, while there are absolutely zero reports of any boards (thus far) that actually employ what you're guessing they do.
You have fallen victim to a common human delusion, that if someone has a lot of experience in something loosely related, they suddenly become an expert on that other topic too.
Yes, the PCB can have unused pads filled as needed. The WHOLE point of doing this is to avoid having to rework the circuit traces every time. If there are inner layers which short parallel paths to those available on the top layer, there is no point to having the top layer traces in ANY implementation of features (or lack thereof).
LOL.
So you're making the "I'm a cranky old fart" argument as a defense?
True.
HOWEVER, it is not common for them to do so when it requires reworking the inner layer. If they do not rework the inner layer, there is no point to having these surface mount pads, as the inner layer is always a closed (sub)circuit and nothing done (whether open or closed, populated) with these surface mount supply lines makes a difference.
Agreed, that's quite true and common. It does not, however, mean that inner layer traces are hardwired which would be necessary if the upper layer pad population is entirely optional... else as I mentioned briefly in another post, there may be entirely separate traces for those features actually implemented. Thus the key issue is whether these empty, and presumed open circuit pads the OP observed are actually those for supply to implemented features.
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