I rebuilt my backup-and-music box recently, because the case was ugly and because I needed to fit another disk for online backup.

I had a Sun 811 case lying around, and another similar to a 411. Neither would take the Epia motherboard, PSU, dvd burner, two 3.5" disks and a 20x4 lcd, but together they can throw off the yoke of conformist PCism! ahem

So I cut out the plastic top of the 811 and riveted the 411 onto it, which gives me space for the drives. A face for the open rear end of the 411 was cut from the cannibalized pieces of my Sony stereo junk and hot-glued in. The frame for the HDs is an old cut-up drive bay, and the support for the burner is a piece of sheet metal that I riveted in (hot-glue isn't strong enough and I didn't want to use expoxy for no reason at all).

 2006_06_05-tosspot-top-inside.jpg 2006_06_05-tosspot-rear-face.jpg

The front with the lcd got a painted fascia (balsa) and the IR sensor was mounted internally this time.

 2006_06_05-tosspot-rebuild-open.jpg  2006_06_05-tosspot-front.jpg

After a shitload of further surgery on the cases and innards I ended up with this pleasant look.


But you can't see the rear in that photo which is good. None of my small ATX power supplies would fit without totally rebuilding the thing (not-so-perfect an idea as I'd basically have to strip all insulation off, then resolder half the high and low voltage connections and cram all the resulting mess into the franken-case), so I started looking at DC-DC PSUs. Like this one. Which I did eventually buy, thinking "the 90W/145W peak PSU I have used so far, so this 200W thing should do nicely". Cost me about us$100 (with a 9A AC-DC external brick and shipping).

Little did I know, and for that matter, too little effort did I spend on research. Plug it in, fire up, works - somewhat: now I get loads of noise on the audio out connection. Not just mains hum but all kinds of activity-dependent crap as well. This is when I started doing the research I should have done before. It turns out that loads of people hate the PW-200-M for being a crap piece of equipment. First, it's nowhere near 200W, and some other speciality PSU manufacturers have accused the makers of shoddy lying advertising. The 5V rail sagged under the load of my two disks down to less than 3V at times. The 12V line is not regulated, so iff you're not using a regulated brick you'll fry your gear (especially the carputer people hate it for that). The smoothing caps are not exactly large at 390-1000uF. (But the form factor rocks, which is why I bought it...)

Tried pretty much everything non-destructive, like powering only the board from the PW-200-M, trying different 12V supplies to verify the noise is coming from the PW-200-M etc...but no joy. It may be useful for really low-power scenarios where one doesn't care so much about power quality (i.e. non-audio application), but for me it's junk...Bugger.

Back to square one: normal PSUs don't fit. Most high-quality DC-DC PSUs like the Opus gear won't fit or require 19V like the DC2DC converters.... So for the time being, I plopped my normal small ATX PSU like an outboard motor behind the box...with some shielding and extra grounding it doesn't affect radio reception too much. sigh

[ published on Wed 07.06.2006 17:22 | filed in interests/comp | ]
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