killswtch.netA geek’s thoughts on various stuff

One day I decided to try out Windows 7 public beta. I had a spare 500 gig drive lying around, so I thought I’d put that in my main machine and disconnect the normal 2x 250gb drives which house my day-to-day Vista install.

So I hooked up the spare drive, got Windows 7 installed, played around for a little while then got bored with it.

Reverting my computer back to its normal configuration was easy. Just remove the spare drive and re-connect the old ones. So I did that, and powered back up and glanced at the side of my perforated case. ‘Funny’, I thought, ‘I don’t remember having an amber LED inside the computer… and what’s that sound? Cables hitting a fan?’. Then came the smell. ‘F^&*ck!!’

After the reflex move of yanking the power cord, I removed the side of the case and extracted one of the drives to find the scene below.

I think there may be a flaw in the design of the SATA power connector, which means that if it’s slightly dislodged then the 5v rail and ground can short out quite spectacularly. And when you have a high-power PSU, the over-current cut-out threshold is set too high so there’s no protection from things like this.

The drive which was damaged is part of a RAID 0 array, meaning that half of the data of my running system was on it. I have 2 independent methods of backup for my main computer: daily file backups of all important files (photos, source code, documents etc.) and a manual perdiodic backup using Norton Ghost. If the worst came to the worst, I should eventually be able to recover all my important stuff and theoretically a complete system image. However, last time I tried to restore from Ghost, the result was very unreliable and had to be dumped.

So, before I considered going down the route of backup restores I thought I’d have a go at repairing the drive.

It looked like only the board had become damaged, and at that only the connector and nearby soldering (the copper tracks had melted into balls) was affected. Ebay is your friend when it comes to finding rare parts, so I started there. I needed an exact match to the drive that I was trying to repair, since I needed a controller board which would work with the internal drive mechanics which should still be working fine.

The first order was a disappointment. The listing was slightly misleading, as it listed the exact model I wanted but the model I received was an equal size but completely different configuration.

The second order wasn’t as bad, but didn’t work. It was manufactured at a different plant, and used slightly different chips and a different firmware version. Although the drive spun up, none of the computers I tried it with would recognise it at all.

2nd replacement drive - didn't work

After wasting a chunk of money, I looked at the corner of my desk and whaddya know … an excact matching drive! Lesson: look around for things hiding in plain sight before wasting money. The matching drive was originally paired with the damaged one, but got replaced when it sounded like it was dying (turned out to be something else).

The identical drives which provided the solution

So, swapping the board from the twin drive to the broken one solved the problem. 2 weeks later I had a working machine again.

This morning I really struggled to get out of bed. Being very tired still, in a nice warm bed while outside it was -7 °C and my room probably wasn’t far off that, it took some convincing that I really did need to go to work. While laying there, between drifting in and out of consciousness, I got to wondering if I could make my room a little warmer without changing the central heating settings or adding another heater. I had the idea that I could set up my computers to respond to temperature.

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A few months ago we were given a couple of old laptops by some relatives. I cleaned both of them up, gave one a fresh install of XP Home and the other Ubuntu. The former has now become the family PC and the latter is sitting on top of some draws in my room unused because the power supply connector is nearly unusable.

Being the lazy person I am, wanting to be able to watch TV and surf from the comfort of my bed, I decided I needed a laptop that actually works. When someone on the UKHA mailing list pointed to an offer on Amazon for an Acer Aspire One L150 (white) for £199, I decided I had to go for it. I wasn’t too keen on the white netbook though, so I paid a little more for a lovely blue number.

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The CurrentCost power monitor has become very popular amongst amateur home automators and those technically-savvy who want to keep an eye on how much electricity they are using (and ultimately how much they are going to have to pay in bills). A couple of months ago I purchased the CurrentCost device and a USB cable to connect it to a computer from eBay. Having just seen their eBay store, it looks like they’ve got a fantastic new model on the way, but this article is about the older version.

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Over a year after it began, the whole-house-audio project is complete. 4 rooms around the house can now be filled with the sound of any of (currently) 4 audio devices thanks to a mixture of hardware and software.

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One thing that has been lacking since the first build of the rack is ventilation. With both sets of doors closed, the inside can get quite warm, especially when iron is turned on. Not any more though, having just completed the installation of 2 active ventilation zones, lighting and a low voltage power supply system complete with rack-mount control panel.

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The audio system that I’m building requires 2 low-power computers: 1 for the touchscreen controller (not using an iPod Touch for the moment) and 1 to act as a webserver and serial-console server.

Once again eBay has come to the rescue, and by searching for ‘geode’ – a low-power processor for Thin Clients & Small Form Factor (SFF) PCs – I found the 2 machines that I needed. These are the specs:

magnesium (the black one)

• 800 MHz Geode
• 256 MB RAM
• 6 GB CF drive
• Onboard graphics, audio, serial, parallel, USB & 10/100 ethernet

£70 + P&P

potassium (the grey one)

• 300 MHz Geode
• 256 MB RAM
• 6 GB 2.5″ IDE drive
• Onboard graphics, audio, serial x2, parallel, USB & 10/100 ethernet

£35 + P&P

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One of the things that has been lacking in my bedroom is a TV. I can watch recorded TV programs, DVDs and other videos on my PC, but not at the same time as relaxing on my bed. While I had a week off work I was looking around the Dabs website and ventured across a real bargain of a TV (now discontinued). It supports full 1080p HDTV as well as being a relatively huge 37″ all for just £539. I couldn’t pass this by, so I spent a while doing investigation work and finally decided to take the plunge and buy the thoroughly indulgent item.

When I designed the rack, the idea was that I would eventually get an LCD TV and it would be mounted to the side of the rack. However, it now contains so much equipment that the weight has become a bit of a concern. To avoid problems with the rack castors collapsing under the load – or even the floor of my bedroom doing the same – I decided to mount it in a more traditional location, on the wall at the foot of my bed (though I had to turn my bed around to make it the foot).

Now I needed something decent to connect it to, with the ability to run MythTV and watch video at possibly 1080p resolution. Boron used to live in a HTPC case, but it started getting a little crowded and warm and with the construction of my rack the innards were moved to a 19″ case. That meant that I’ve had a spare high-quality case lying around doing nothing for a while. Now I had the opportunity to bring it back into service.

The Core 2 Duo in my gaming machine has done nothing but impress with its performance and cool running, so I knew what I wanted to base this new machine around. The E7200 2.53GHz was the cheapest Core 2 available on Dabs, so into the basket it went. I wasn’t too bothered about having a high-spec for the rest of the system, and indeed it needs to be farily quiet and cool so for graphics I went with the Asustek Radeon HD3450 256MB and a cheap-but-capable Gigabyte motherboard.

The processor ended up getting swapped for the slightly slower one in aluminium, so I got a small upgrade for gaming at the same time. For the OS I’m currently experimenting with MythBuntu for amd64. I’ve also taken another look at LinuxMCE, which I might give a go some time.

The new machine was named barium, and sits fairly neatly under my bedside table.

There are 4 audio zones in the house, each requiring it’s own amplifier and pair of speakers. I’ve just purchased the last of the amplifiers, which completes the selection of hardware that’s necessary within the cabinet. I took the opportunity to rearrange the order of things in the rack a little to tidy things up.

We recently had our latest electricity bill in, and it was pretty huge. To try to reduce the next bill, reduce the heat output of the cabinet and speed up the network I decided to combine 5 switches into one.

Before now all devices in the house have been connected to one of 3 switches: a 5 port gigabit switch (4 usable ports, 1 for uplink), a 24 port managed 10/100 switch, and a 4 port managed gigabit switch (3 usable ports, 1 for uplink. These switches used a combined 51 watts, and are on continuously, although lately I’ve switched the 4 port gigabit switch off to reduce the noise levels in the cabinet.

I have now replaced these 3 switches with a single 24 port unmanaged gigabit switch. It was a 2nd hand purchase from eBay, and had 2 faulty fans. I’ve replaced one of the fans and left the other disconnected with no problems so far. This switch uses about 17 watts of power.

In addition to consuming 34 watts less, I’ve also freed up 1u of space. With all the amplifiers, computers, networking equipment etc. space is starting to become a premium and the weight of the rack is becoming a concern.