What wires go to what terminals?

Question

I have several older model computers (but not all of the parts are with them) that I'd like to try to use the parts from one to get at least one or two up and running.

But the one thing that confuses me is those little wires (most are twisted as a group) that are attached to the case but connect to the mobo. One is the power button, one is the speaker, one is the HDD LED, one is the Keylock (whatever that is)?? and and the others are I don't know?

How does one determine the polarity of these wires if they're not marked on the wire or the mobo....especially the power button? What about polarity for the HDD LED?

This is confusing and prevents me from making a move to build a computer from parts basically......I need to know what goes.

The computers are too old to find anything on the web about the mobo's so I'm out of luck there.

What do I have to be concerned about as I try to understand what wire goes to what mobo connection?

Answer 1

have a look at the motherboards. you should see 2 rows
of jumpers(sticking out pins) on the mother board. To find these you have to search for "jp" notation on the mother board which denotes jumpers.
now the wire have the labels written on them like-hdd led,power switch,power led etc.
Remember all labels should face the outer side when you put the terminals on the jumpers.
beside the jumpers in very small letters the exact position of each wire should be given. if you do not find it beside the jumper it may be some where else on the mother board.
for the polarity of the wires:
there are two types of wires 1> coloured wires and 2> black and white wires.
take the power switch wires and chk for which set of jumpers the computer turns on.
Dont worry, the voltage for the internal parts of the computers is not so high as to damage anything if any wrong connections are made.
the highest voltage in the computer cabinet is only 12 volts.
as soon as you find the correct jumpers maintain the order of the colour of the wires.
for example:

1______ 2 ______3______ 4______5______ 6 ______7____8
......power .............power led............
.........sw.....................
green...white......blue..black.......
that is maintain the order of the power switch wires --coloured and black/white --coloured and black/white wire.
do the same thing for the other row.
remember the labels shoud be facing the outer side for both rows.
once you connect the wires of the speakers it will give you a beep code if your connections are wrong.
best of luck

Answer 2

with the power switch and the reset swith, there is no polarity. all it does is connect the two wires together. if you had the motherboard laying out on your counter for testing, you could turn it on with a jumper, such as a conductive screwdriver or paperclip or something.

as for the power light and hard drive light, usually the negative wire is the white wire. on the mobo, the positive post is the one that is toward the rear of the comptuer.

and those other wires aren't really needed. the most important one you must connect would be the power wire. everything else is just an added bonus. and don't worry about blowing anything if you put it on backwards. it just won't light up if that happens, then you know you got it right if it lights up.

case speaker: not really needed unless you're troubleshooting for the error beep codes, that speaker isn't worth much anyway, and you will probably want your sound coming from the sound card into external speakers of some kind.

Answer 3

Yes, need to get details from the case, and the mboard, if the wires on the case do not show the polarity +/- then you will need to get that info.

This is one reason I tell folks if you are buying a used mboard or case, try to get the exact info so that if the person does not have the instruction booklet you can look it up online.

Typically when I upgrade a new computer the things I will usually replace are mboard, processor, and sometimes the case, usually I use the DVD/CD Rom drive, the hard drive, typically memory, sometimes the graphics card will get upgraded.

But you get the point, mboard is exremely important to have the docs so you know where to plug those wires into.

Answer 4

Usually the pins are marked in very tiny letters. Get a magnifying glass and look them over real good. The keylock you probably won't use, older computer had a key on the front to lock out intruders

Answer 5

The easiest aproach is to download the manual from the mobo manufacturers website. You can download the manual for free and it should have all the info and board pinouts you need. If you cant find the info, send me the mobo mfg and model numbers, they are out there somewhere. Sometimes you have to dig deep on the website, look for archives. Most reputable companies have them.