Cables

Building a computer involves connecting a lot of cables. Let's see if I can remember without opening the case. Here it goes, in no logical order whatsoever.

• Motherboard power. That's two cables, actually, since motherboards (well, CPUs, that is) consume such enormous amounts of energy nowadays. Easy enough, locate the connectors on the motherboard and the power supply lines. They will only fit in one way anyway.
• Power Supply Fan sensing cable. Basically, the power supply regulates it's own fan speed depending on temperature. The PWR_FAN cable needs to be connected to the appropriate connector on the motherboard. In this way, various useful tools can monitor the power supply fan speed.
• CPU fan. Even more important, since the motherboard can use this to control the CPU fan speed. If the CPU gets hot, increase the CPU fan speed, so it gets cool again. Back in university we used to call this a feedback loop. Had all to do with Control theory. Hmmpf. Just connect the cable, I guess.
• Chassis Fan. Also known as Case fan. This is the one that blows hot air out of the case. Also controlled by the motherboard. This one was a bit hard to connect, since the cable was just long enough, and the graphics card got in the way. Managed to connect it, though.
• Then the power supply has two Molex connectors labeled "FAN ONLY". Might as well connect these to the case intake fans. Presumably, the voltage on these connectors is dependent on the power supply temperature. Better not connect any drives to it.
• Power connectors for the optical drives. Straightforward, just plug 'em in.
• Power connector for the floppy drive. Only one way to connect it.
• Power connector for the hard drive. Let's wait with discussing that one.
• Power LED(s) connector. Hook it up directly to the power supply.
• Audio cable from the DVD drive to the motherboard. Not really needed, actually. Might as well connect it anyway, otherwise I might lose it.

This is getting boring. The following cables were connected without any problem: GAME/MIDI port, front panel FireWire, front panel USB, bracket USB. On to more exciting stuff.

• Floppy data cable. It was actually possible to connect this in two ways, one obviously being the wrong way. Hmmm. Instructions say to connect wire 1 on the cable to pin 1 on the drive (and the rest is correct automatically). Duh. Wire 1 is actually marked on the cable. So which pin on the floppy drive is pin 1? I couldn't find any markings. Hmmm. Internet to the rescue, and made an educated guess on how to plug the darn thing in. Guessed right the first time.
• CD-ROM cable. This was slightly annoying, since I only had one (came with the motherboard), and I had two CD/DVD drives. No cables with the drives, surprisingly enough. Now, you really only need one CD-ROM cable, since it has two connectors, one for the master drive, and one for the slave drive. Both would be on the same IDE channel then. However, since I have two IDE channels on the motherboard, I wanted to hook up each optical drive to its own channel. That supposedly increases drive performance. I didn't need the other IDE channel for the hard drive, since it is SATA. So, I could do one of three things.
  - Use a hard drive cable for the second optical drive. I was a little uncomfortable with this, since HDD cables have 80 wires, and CD cables have 40 wires. Connectors should be the same, however, I still didn't like the idea, since I wasn't convinced that the wires would be connected identically.
  - Buy another CD cable. Hmmmpf.
  - Cave in, and put both drives on the same IDE channel. This should actually not be a big problem, since millions of PCs have things hooked up this way. Also, it would mean one less cable in the case, whicj is a good thing. Better airflow (supposedly), and less clutter. I decided to go with this, since the CD-RW drive won't see all that much action anyway.
• On/off switch (front panel). I was rather puzzled by the fact that the cable connected to the (case) switch had different color wires, but no marking which one should go to ground (the motherboard connector does have this marking). Just guess how to plug it in, shouldn't matter, since a switch has no polarity, right? Same deal for the HDD LED and the reset switch. The polarity on the HDD LED does matter of course, since LEDs have a plus and a minus (anode and cathode, if you are electrically inclined). A wrongly connected LED will typically not work. Just plug it in the other way around, should that happen.
• Hard drive cable. This was an interesting experience. Western Digital has incorporated two interesting features in my drive. The first one is two different power connectors. One classic Molex connector, and one SATA power connector. The manual warns against connecting both at the same time. Makes sense. Then, there is this so-called SecureConnect cable. Supposedly much better than regular SATA connectors. And indeed, it connected to the drive with a solid, reassuring click. The drive side of the cable covered both the power and data connector. However, the other end of the cable had a standard SATA data connector. Would it be possible that the data connector also carried the power? But then the power would flow through the motherboard traces, which seems a dubious proposition. On the other hand, plugging in the Molex power as well could possibly fry the drive. Hmmm. Just connect the SecureConnect cable then.
• Front panel audio. The case came with a cable to connect the front panel audio connectors to the motherboard (actually, the front panel is on top of the case, but who cares). All wires were neatly labeled. Connecting them required removing two jumpers from the motherboard. After connecting all pins, I had two wires left, labeled L RET and R RET respectively. However, these two wires were clearly connected to the L and R wires. Us electrical engineers recognize these things. We also have a natural abhorrance of short circuits, so I didn't connect these buggers. I was a little confused about the purpose of these wires. Suffice it to say that things would become clear later.

After all this connecting, it was time to turn the beast on.

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