Computer Wiring

[Thrawn183]

Alright, I'm building a computer for the first time. I've got all the hardware in and almost all of the wiring set up. I have encountered only 2 problems I have not been able to solve by taking a step back and thinking about it rationally.

1) The power supply has 3 sets of power cables coming out of it. Two were easy to fit into the motherboard and are of no concern. The last... I can't actually figure out where it is supposed to go. I'm running power to every component I've got except for my graphics card, but I don't think it needs any power. The plug on the cable has 8 holes surrounded by plastic in two rows of four. The only place that matches that is the back of the power supply itself. Now, normally I would just plug it in, but I'm hesitant to plug the power supply into itself, as I suspect that would result in a rather spectacular short circuit of the power supply. Is this a cable that I even need to bother with?

2) I am trying to run the cables for the Power Switch and the Reset Switch. I have found the location that they should plug into the motherboard, but I'm not exactly certain where each is supposed to go. Following is a drawing of what the spot on the motherboard looks like. The cables have plugs slotted to take 2 bare copper prongs. In the picture, the circles represent spots with the copper prongs and the circles with X's in them represent it's a spot where there isn't a copper plug. On either side of the drawing I have written what color plastic the plugs are, as well as what color the wires are that I'm trying to plug in.


http://img638.imageshack.us/img638/6528/computerwiring.jpg (http://img638.imageshack.us/i/computerwiring.jpg/)


Any help you can give me would be appreciated!

[valadil]

1) Ignore it.

2) This is IMO the hardest part of setting up your computer. My advice here is to read the manual in great detail. It usually tells you what each pin does and what they expect. It won't say "plug green into red" but it'll tell you where to plug the 1.5v pin. Then go through your power supply's manual and find the same info. If you're lucky some of this data will be on the pins themselves.

[Erloas]

The power supply should have a lot of power cables coming off of it, several of which probably won't be used.

The power supply manual should tell you what each plug is set up as. There are 2 different sizes of the primary power plug, 20 and 24 (sometimes listed as 20+4) which most power supplies have has a 20 with a separate (but generally in the same bundle) 4 pin that attaches to it to cover both types. I'm pretty sure most motherboards use the 24 and most power supplies have it set up in the 20+4 connectors. These connectors are usually white.

The next one is generally the processor power (also on the motherboard but generally very close to the CPU), it will be 4+4 using the same idea as above. Old ones generally used 4 and new ones generally use 8. It has the same spacing and generally the same size as the previous plug and generally also white. They are keyed differently so there is only one way to plug them in.

The only other 8 pin I can think of is PCI-E plugs used for video cards, but they can be 6 pins as well. They are generally a bit smaller then the MB/CPU and generally black. Some video cards could also use the straight 4 pin power, the same as what CD, Hard drives, fans, and other peripherals use (though a lot of CD and Hard Drives use SATA power connectors now).
Most video cards require power from the power supply and not just from what the motherboard can supply, about the only things that don't are low end cards.

I haven't seen a power supply that ever plugs into itself, and it wouldn't make any sense. I think there might be some that can take feedback from motherboards, but I can't think of any on consumer motherboards and power supplies, maybe on high end server equipment.


2) This should be covered fairly clearly in the motherboard manual. I forget the default colors. For all of the switches they are generally 2 sockets and go on both pins of the same color. It doesn't matter which way because it just closes a contact for a second so there is no polarity involved. Generally with LEDs they have one side marked with a +, and I think the internal speaker is 3 with the center one missing. That however is going off of memory.
If you mix up the PW and RSET switches is will not harm anything at all, it will just mean you have to push the other button to get it to come on/reset.

[Thrawn183]

Awesome! I went back over the instructions for the motherboard, and now that I knew what to look for, I figured it out. I think... I think that means I'm actually finished with this build!

All that leaves now is drivers and other software! Man, I'm so stoked!

[Moofaa]

Yeah, reading this makes me want to build a new computer, but since I usually spend 2-2.5k on my gaming beasts it will be at least a year or two of saving.

On my second build I had no idea that "newer" (at the time) graphics cards required their own separate power plug. My last computer didnt need it. Nothing in the manual or from the manufacturers site mentioned this, and I hadn't ever heard of it. File this up there with all that other "obvious to everyone else but you" information.

So imagine my frustration when I fired up my latest and greatest system to only have it squeal like a stuck pig because the graphics card was trying to draw all its power through the PCI-E slot, then spending hours stripping the system down entirely and rebuilding it to make sure everything was plugged in correctly and reading manuals, FAQs, and google searching. Finally I called a local computer shop and talked to a guy there who, after also being stumped for an hour, said "Did you check the connection from the PSU to the card?" and I was like "The wha-".

Apparently its too hard for a manufacturer to print "PLUG PSU CONNECTOR HERE" with an arrow on the technical drawing in the manual.

[thubby]

is the unknown wire a normal wire or is it like a ribbon?

[Irbis]

1) The power supply has 3 sets of power cables coming out of it. Two were easy to fit into the motherboard and are of no concern. The last... I can't actually figure out where it is supposed to go. I'm running power to every component I've got except for my graphics card, but I don't think it needs any power. The plug on the cable has 8 holes surrounded by plastic in two rows of four.

Can't you find a photo on the net and show us? :smallsigh:

If you're building PC from scratch, you're supposed to know who made the power supply, at least.

And wiring isn't the hard part. Setting the BIOS properly is one :smallamused: