DIY computer case

Working on the well-established principle that he who has the most toys wins, I was looking at getting a DVD recorder, PVR and Freeview box to use with my new LCD TV. But then it occurred to me that all of these things could be done by a single computer, which would mean I could also surf and read my e-mails during commercial breaks (on Channel 4, obviously, there's nothing on ITV that is ever worth watching as far as I can tell...)

So I bought (yup, eBay again) an MSI Mega 651 small form factor PC barebones system. Look, there it is on the left. Well, there's a picture of one off the MSI website, it's hasn't been kicked about by the postie as much as the one which got, ahem, delivered to me. Yes, (once again) despite being described as being in excellent condition, when I took it out of the box it was fairly battered having been dropped fairly hard at some point. However, given that I had dropped the box it was delivered in - and despite the fact that I was
fairly sure I hadn't dropped the box hard enough to do that much damage - I wasn't really in much of a position to blame the vendor for the damage.

Anyway, the damage was relatively minor and mostly confined to the rear of the case, so I built it up anyway with a Northwood P4, 1Gig of RAM and a 120Mb Barracuda Seagate hard drive. Plugged it into the TV's VGA port and fired it up.

And ye Gods, it sounded bloody noisy. Now I suspect the PSU wasn't especially happy after the effects of being dropped, but the general noise it produced meant that there was no way you could leave it on the whole time in the living room. Shutting the door of the AV unit underneath the TV helped reduce the noise but the CPU and case temperatures started to rise from merely alarming to abjectly horrific. A rethink was on the cards.

I looked into super-quiet SFF computers and decided that, at the end of the day, there wasn't one other than the Shuttle Zen and that was a bit gutless. One of the problems seems to be that there are quiet components out there, but there's no chance they'll generally fit in a SFF which uses its own proprietary PSU, CPU cooler and the like. Also, I didn't really need to have a SFF computer - the AV unit's designed to take full-width hifi separates, so space was fairly ample. In the circumstances it seemed daft to have a tiny wee box in a huge great space, only to have it whir away and overheat because everything was crammed in so tight.

So I looked at media PC cases (or Home Theatre PC cases as they're also called). Some looked OK, but none looked like they were really what I was after. So, as ever, the answer appeared to be to make one from scratch. I really think I need to hire someone to follow me around, so that whenever I say 'not a problem, I'll just make one' they can give me the good kicking to the head that I need in such circumstances...

First thing was to spec and buy the components. I needed

- a motherboard with a SPDIF output to feed into the AV receiver and which could use the P4 Northwood processor

- a CPU cooler which would be nice and quiet but capable of cooling a 2.6G Northwood

- some way of quietening down the hard drive

- a PSU less inclined towards impressions of fighter jets taking off

- a fanless graphics card which could nonetheless work with Windows Media Centre

and all the other usual stuff. In the end the spec was -

- ASUS 8Xwawawa motherboard

- Zalman 7000 CPU cooler

- SilentMaxx HD enclosure

- XFX NVidia FX5200 graphics card (NVidia seem now to pretend they didn't make the FX5200 chipset for some reason. Hmmm)

- allegedly pretty damn quiet Zalman PSU

- silicon blocks for mounting the DVD drive on

- a 120mm ball bearing case fan

- lots of bits of silicone doodahs

- a Nebula DigiTV Freeview card

I've made the case from aluminium. In hindsight that wasn't necessarily a very good idea as ali is fairly happy to resonate away in sympathy with any other sources of noise or vibration. However, the idea was to use thick aluminium plates both to prevent the transmission of noise and to use as a big heatsink.

I bought the aluminium plates off, yup, eBay. The front and rear panels are 5mm thick, the base is 3mm thick as is the intermediate shelf, and the sides are a whopping 12mm thick. The first job was to cut them roughly to shape with a hacksaw and jigsaw and then to use the milling machine to clean up the cut edges and make sure all the panels were square. Yes, it's probably overkill to use a milling machine just for trimming panels, but if you've got it, use/flaunt it...

Once the panels were square and the edges flat I drilled and tapped holes in the 12mm side panels to take M4 bolts. These bolts the other panels onto the 12mm side panels. The holes for the top and bottom panels I drilled on the pillar drill. However, the panels are too long to have holes drilled in their ends in the pillar drill (you can't get the table low enough to give enough space) so they were done by hand with the panel in a vice.

Once I had the main panels (other than the top panel, which I hadn't got the material for) bolted together I could work out more precisely where everything was going to go. The motherboard was the first thing to put in place, and as it seemed obvious that this should go on the left hand side towards the back of the box, I drilled and tapped some holds for some brass standoffs for the mobo to sit on.

Once I'd worked out where all the components were going to fit, it was time to make the necessary holes in the rear panel. When I worked out where everything would going to go, I tried to work out and stick to a plan for the airflow through the machine. Effectively, the idea is that the air travels in a 'U' shape, in through the rear of the machine in the gap between the graphics card and the DigiTV card, over the graphics card, round the gap at the end, over the HD and DVD drive and then out through the 120mm case fan and PSU fan with the CPU cooler positioned just behind the case fan. The only slight problem is that there isn't space for the 120mm case fan in side the case - it'll have to be mounted on the outside of the case. However, since there will be plugs and sockets going in the back of the case which will increase its effective depth by at least the 20mm depth of the fan, I don't think this will be an issue in practice.

It was obvious from the outset that there would need to be some intermediate shelf in the case, not only to provide something for the DVD drive to sit on but also because there simply wasn't enough room for everything to rest on the bottom panel. So, I made up an intermediate shelf panel using some spare 3mm sheet. It's bolted onto some strips of ali angle which are in turn bolted onto the side panel using M4 tapped holes about 8mm deep. When the case is finally bolted together for what will hopefully be the last time, I'll use silicon sealant between the metal/metal interfaces wherever possible.

The little black thing you can see in the picture is a piece of silicon which the HD enclosure will be suspended from. Instead of mounting the SilentMaxx enclosure rigidly to the case (albeit using the silicon mounts built into the side of the unit) I've decided to suspend it from the intermediate shelf using this silicon bits. I think they're designed to be used to mount fans onto cases, but as far as I can see they'll be perfect for this.

In order to mount the DVD drive and the little LCD panel which controls the fans (CPU, case and A.N.other - I've got plans for that) it was necessary to cut holes in the front panel of the case. I could have done this with a jigsaw, drill, and file, but in fact I used the milling machine with a slot drill to mill out the holes, and then a small square profile file just to open out the corners (of course, without some fairly special kit you can't mill square holes in things - square end mills stop being square when you rotate them... ;)

I'm still wondering what to do about the finish on the front panel. The most understated look would be to merely make the front panel brushed by using a sanding block to give a brushed effect. However, it's got a couple of scratches on it, and the brushing won't get rid of those. I could anodise it black, and if BO-bloody-C don't hurry up with my welding gas I still may.

Third option is to skim a bit of it using the milling machine giving a distinctive machined finish to it. It is distinctive, but it's a bit bling given the understated black of the Cambridge Audio kit. Hmmm, anodising may be the way forward. But then the silver DVD drive's going to look a bit pony...

At any rate, that's what it all looks like with the front panel on. The finished article will retain this rather sparse appearance - the only things to be added are the two stainless steel switches for on/off and reset - cheers Steve. There will be a card reader for the smart cards so I can watch TopupTV and some other peripherals but these will be tucked away elsewhere and connected using the USB connectors on the rear panel.

One of the reasons for using such thick ali panels for the sides of the case is to try and get them to work as heatsinks. In order to increase the surface area they have for dispersing heat, I've milled some slots into them. For some reason I've taken loads of photos of this - I can only assume that the mind-numbing boredom associated with milling 22 6mm wide and 4mm deep slots which are about 280mm long led me to think that taking photos of it would amount to a bit of light relief.

Anyway, I'll spare you the reams of exceedingly dull photos (yes, even more dull than the ones above) and just include this one which shows the slots having been machined. The gap in the middle is to make sure that one of the slots doesn't break into the tapped hole for the intermediate shelf thing.

As I mentioned above I've been a bit concerned about the large flat aluminium panels resonating. I've bought some Brown Bread sound-dampening stuff which I'll slap on liberally. However, it occurred to be that welding some stiffening ribs on the larger thinner panels probably wouldn't go amiss. It would also be the perfect excuse I don't really need to fire up the A/C TIG welder I bought not so long ago. In order to do this I needed some Argon gas. Until now I've used hobby bottles with the MIG welder and to be honest I don't really do enough welding in MIG to justify anything else. However, the TIG welder's set up for bigger bottles and although I could easily convert it to take hobby bottles, TIG welding does tend to get through gas rather quickly. So, big bottle it is.

But of course you can't just buy a big bottle of gas. No, you have to set up an account with BOC first. Which at present is proving easier said than done, and that's what's stalled the build so far. So, waiting for gas...

Well, not bad for a first try...Well, the good news is that the gas is here and my AC TIG welder (off eBay, of course) works pretty well. The bad news is that welding ali is still bloody hard. External fillets and butt welds aren't too bad, but trying to do internal fillets is really not easy. The strengthening, or rather stiffening ribs, seem to work reasonably well, however. The panels are certainly less inclined to resonate than they were before, which is good seeing as entire point of this exercise is to make a computer that's as quiet as possible. I've added stiffening ribs on all the flat, thin panels although I must admit that I gave up trying to weld them after a while - personally I'm blaming the eclectic mixture of unknown grades of aluminium I'm trying to join together rather than my abject inability to weld. Where I haven't welded the stiffening ribs on, I've adopted traditional kit car building techniques - rivets and polyurethane sealant.

Once all the welding and rivetting was finished, it was time to start putting everything together. As I rather expected, there wasn't enough room between the top of the processor cooling fan and the bottom of the 120mm case fan, so the case fan had to go on the outside of the case. It's held on by silicone cords with a silicone damper between it and the rear panel.

As you can see, I bought some circular IDE cables for the hard drive and the DVD player, on the basis that they'd present less of a restriction to the airflow than a flat ribbon cable. Given that neither had a secondary drive on them, I chopped them down so they only had two, rather than the standard three, connectors on them. Unfortunately it then turned out that there wasn't enough room for them to pass between the suspended hard drive and the memory, so I had to go back to using ribbon cables. So if anyone wants a couple of butchered circular IDE cables...

The build continues. The intermediate shelf is now in and you can see the hard drive suspended from it. The hard drive's suspended from the ali plate using the same kind of silicone cords which hold the case fan in place. There are ali brackets on either side made simply from some short sections of ali angle with some holes drilled in them. The was the point where I realised the circular IDE cables weren't going to fit...

Good sign on the wall, eh...And there you go, the build's nearly complete. The little plate holding the graphics card and DigiTV card is in place, the case is all bolted together, and we're nearly ready to go...

So I fired it up and other than the motherboard bleeping about the fact it didn't think a CPU fan was attached (the CPU fan's driven by the fan controller in the front panel, so the motherboard thinks there isn't one and starts complaining loudly when you boot up) all went well. I installed Windows Media Centre. All was still going well.

Then it turned out that the wireless keyboard with an integral trackerball had stopped working completely (and no, I tried changing the batteries, it wasn't that). So I got a cheapo cordless keyboard and mouse package from PC World. Which was a swine to get working, but we got there eventually.

Then I tried to get the wireless adaptor working. It's a Linksys WUSB54G for anyone that's interested, and it's crap. I'm unfortunate enough to have two off them, and they're both hideously flakey. In the end I had to reinstall MCE from scratch and install the wireless adaptor again. It seems that the only way to make it work is to:

1. Install the utterly shoddy Linksys software

2. Connect the USB wireless adaptor

3. XP installs the drivers

4. Disconnect the wireless adaptor

5. Remove the Linksys PoS software

6. Reboot

7. Connect the USB wireless adaptor again

8. Let the Windows hardware wizard load the drivers direct from the CD.

Despite the fact that the adaptor claims to have a signal varying from 'low' to 'very low' it rattles along at a fair old pace, so that's OK then. The graphics card install was pleasantly straightforward and I was able to adjust the resolution to meet the TV's native resolution (1280x768). So, we have visuals, we have network connections. All is going well.

However, the next problem was getting the onboard soundcard working properly for Dolby 5.1. The idea was to use my AV receiver to do the decoding, and simply use the soundcard as a pass-through to send the AC3 stream to the AV receiver via the onboard SPDIF socket. Should be easy. It wasn't.

Actually, before that there was the problem of trying to get DVDs to play at all. Now, bear in mind that this is Windows XP
Media Centre Edition. Now, surely it wouldn't be too much to expect something which sets out in life to be a Media Centre to be able to play DVDs, would it? But no, you have to download (and pay for) a plug-in for DVDs to work. Frankly, this is totally pony. It's like selling an off-road vehicle with pram wheels. But there you go - that's Microsoft products for you... After a few hours research to work out the best way of making this utterly crippled OS work properly, I downloaded a trial version of NVidia's DVD decoder, and after a few minutes fiddling with the various interrelated but wholly independent resolution settings, I could watch DVDs full screen. Woo, and indeed, hoo.

It was at this point that the sound card problems kicked in. No Dolby 5.1. The onboard pass-through was activated, but the output was only 2 channel PCM. Hmmmm... More research on the 'net. It turns out that the drivers for the onboard SoundMax soundcard are nearly as flakey as the ropey Linksys wireless adaptor drivers, and that they need a bit of help. The first thing was AC3filter, which helps get a pure stream of AC3 coded output to the SPDIF output. This worked OK, until you tried pausing the DVD. At this point, when you restarted it, there was no sound. If you stopped the DVD playing and then restarted it, the sound came back, and seeing as this only took a couple of seconds it wasn't the end of the world. But annoying all the same.

In the end, with a few more hours net trawling, it turned out that the ASUS driver was a bit out of date and that other motherboards had more up to date drivers. I eventually found an MSI mobo with the same sound chip and the same Northbridge hardware. I installed that, and lo and behold I could pause and restart DVDs with sound. Quite why ASUS don't offer that driver on their website as an option is beyond me...

On the initial abortive installation I got the DigiTV card working but the signal wasn't too great. Some channels were OK, but mostly ones I'd never want to watch (CNN and the Travel channel). BBC had a lot of artefacts, and ITV was missing completely. Mind you, I was trying to get the signal from the wall socket to the DigiTV card down 3 daisy-chained bits of el-cheapo wet-string aerial cable, nestled lovingly around a selection of mains cables and speaker cables, so that didn't come as a total surprise. Still, I reckon the aerial needs upgrading to get a good enough signal for digital.

So that's the next job - get a Nice Man to come along and get me a decent TV signal...


I ended up scrapping the whole thing. With a decent RF lead I got it working OK and DigiTV was really rather good. The trouble was that in the confined space of the AV cabinet the computer was still bloody loud. Sat outside the AV cabinet on the floor the fans could trundle round at a modest pace, nice and quietly, and it would stay nice and cool. But once in the AV cabinet it got waaaay too hot and much too noisy.

So, I bought a Zalman Reserator kit and installed that, with extra heat sinks bolted to the sides of the case. The idea was that the computer would be inside the AV cabinet with the Reserator outside it pumping all the heat out. Fine plan, but after fitting the Reserator the damn thing wouldn't work. Nada, nothing, not a sausage. Even after half a day's vehement swearing, it still wouldn't do anything more than feebly beep an undocumented error code and then stop entirely. Great.

So, on the basis that I wasn't prepared to spend even more time fannying about with this tempramental PoS, I scrapped it and bought a Topfield PVR5800 and a Cambridge Audio DVD player. That got me spending hours and hours hacking an ASUS WL-500g Deluxe router so I could connect the Topfield to the rest of the network, but that's a different story.

Moral of the story? MCE sucks big time and computers suck big time as media devices if you want a nice quiet easy-to-use box that you can stick in an AV cabinet and just have work. If you've got waaaay to much time on your hands and have run out of walls to bang your head against, then build a Media PC...

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