PC PSU connector types?

They are one type of Molex connectors, referred to as 5.25" drive connectors in this application.

That is the 3.5" drive connector. The holes are on .1 inch centers like the pin sppacing on older DIP IC packages. They are also availible from Molex.

It was the CPU power cable on some motherboards.

Hi!

Let's see if we can't break this down and make it a little easier.

The "Molex connectors" you see discussed are the larger ones that have four holes in them. They are so named because Molex is the company who developed them (AFAIK). As you've seen in your computer, these usually plug into devices like hard disks, CD-ROM drives and some older floppy diskette drives. You'll have between four and six of these, and maybe more or less in some exceptional cases.

The smaller rectangular four wire connectors are used for physically smaller drives, such as your 3.5" floppy drive. Some internal Zip drives use these. There are probably only two of these.

As for powering the motherboard, you usually have two major groups of plugs, at least that I'm aware of.

The first is a long rectangular plug that fits into a matching socket on the motherboard. This is the so-called "ATX plug". It is responsible for providing power to the motherboard. There is only one of these.

The next plug is a four pin square. This plug has two rows of two pins each. It is used to power the CPU core on most motherboards. There's only one of these as well. It has all yellow and black wires going to it.

Other plugs:

The so-called SATA-plugs are long and very thing rectangular plugs often filled with little edge-connect pins. They're usually made of black plastic at one end.

Your current power supply may have a few other wires coming out of it that aren't connected to anything at all. The ones that look like the "Molex plugs" or anything described above are usually for future expansion. (Don't be too surprised if you have extras--I've seen PC power supplies that had many more of these than could ever be used. I've also seen some with far too few for the case they were installed in.)

Other plugs that don't fit any description above are probably just not used in your computer, and needn't be hooked up.

Your best bet (if you don't mind shopping locally) if you're not sure what to buy is to head into a computer shop where the people know what they're up to and take your old supply with you. They'll know what you need and can explain things if you have questions about the plugs.

William

Thanks both, those have really helped. Also found a good picture here:

Molex company makes lots of different connectors, including the power connectors for mobos and 3.5" hard and 5.25" drives (often wrongly called IDE power connectors for PATA drives). I don't know what 3.5" connectors are. Could they be for 3.5" floppy drives?

Probably.

The 4-hole one is for extra +12V power for certain mobos. The 6-hole one is probably for high-performance graphics cards.

Here's a guide to PSUs that includes descriptions and photos of the various connectors:

It also lists good and bad PSUs, but in its list of good ones the best are probably Antec, Seasonic, Fortron-Source/Sparkle/Hi-Q/PowerQ/Trend, Zippy-Emacs, and PC Power & Cooling. I don't know about all the other brands, like SilentX and Silverstone, but you may want to look for Fortron (most model numbers start with "FSP") because they're not only good but also cheap. Thermaltake/High Power/Sirtec isn't the best. Other good brands are Delta and Lite-On, which in the U.S. are rarely sold on the retail market, and Channel Well, although for the latter you have to be careful because their quality is all over the place, and you want only those that are like the Antec SmartPower and TruePower, their "B" and "A" suffix series, i.e., CWT-350BSP, CWT-430ADP ("S" = single fan, "D" = double fan, "P" = power factory corrected).

Great, thanks Larry.