Public service announcement

[fivemack]

When you assemble a computer from parts, the case comes with umpteen small screws.

Some of these have flanges and round heads, some of them have flanges and hexagonal heads.

The motherboard is attached by screwing little brass hexagonal standoffs into holes in the case, then resting the motherboard on the standoffs, and screwing it on.

USE THE SCREWS WITH FLANGES AND ROUND HEADS.

The screws with flanges and hexagonal heads are one-sixteenth of a wotsit too big, and prone to jamming in the standoffs. Mr Murphy will assure you that this will happen most in the standoff which is most inconveniently located on the motherboard.

Once jammed, the screw and standoff rotate as a unit, and there's not enough give in the motherboard for the standoff to rotate out of its hole in the case; if you could hold the standoff with pliers and unscrew the screw, this would be fine, but the standoff's underneath the middle of the motherboard at this stage.

The way that finally worked to unjam the standoff was to remove all the removable components and all the other screws from the motherboard, then pull very hard with a large pair of pliers on the head of the screw until the screw, standoff and motherboard flew out of the case as a unit. Detach screw from standoff by holding standoff in Big Pliers and turning screw with driver; discard screw and standoff, get new standoff and correct screw from bag of small screws, achieve glorious success.

This scraped some solder-mask off the motherboard tracks, but didn't actually break it. This time.

Of course, motherboards are not that expensive, so even if you break one from time to time it's cheaper to pay for the occasional whole motherboard than to pay the 15% overhead on all the components that your local shop will charge for assembly. But for a dual-core 64-bit high-performance processor to be stymied by a screw one sixteenth of a wotsit too wide is unavoidably irritating.

Comments

[aardvark179.livejournal.com]

Stay away from flat pack furniture, it's for your own good. :-)

[fivemack.livejournal.com]

I can do flat-pack furniture; it has Very Clear instructions and a list of parts, and generally if it's using two kinds of bolts one of them will be three inches long and made of steel with an Allen-key head, and the other half an inch long and made of brass with a flat-tip screwdriver head, and it will be clear that the one will not substitute for the other.

Honest to God, I thought the shapes of screw-heads were a decorative matter.

[papersky.livejournal.com]

Honest to God, I thought the shapes of screw-heads were a decorative matter

*choke*

This reminds me rather too much of the incident of zorinth and the graphics card that didn't quite fit.

[ckd]

I'd ask, but I'd expect you would want to get zorinth's okay before telling the story.

Mixed technologies

[nojay.livejournal.com]

The screws that go into sheet metal have wide-pitch threads, self-tapping (sort of). The other screws are fine-pitch (machine thread) designed to go into threaded holes like the little brass stand-offs. You might notice the stand-offs themselves have wide-pitch threads on the bottom section since they go into sheet metal.

[ewx.livejournal.com]

I think the best advice would be to try the screws for size without an intervening motherboard...

[cartesiandaemon.livejournal.com]

Oh yes, I wouldn't start from here!

[cartesiandaemon.livejournal.com]

I expected the punchline to be that you measured them before you started and were just explaining in case anyone else was going to get it wrong :)