Wikipedia:Reference desk/Archives/Miscellaneous/2018 April 27

= April 27 =

Used parts in electronics purchased as "new"
I recently read that, at least in the 1990s, that PCs sold as "new" frequently used second-hand parts.

My questions
 * 1) Is this true today?
 * 2) Is this, or has this, been true in other consumer electronics?--Leon (talk) 19:22, 27 April 2018 (UTC)
 * Do you mean only branded PCs made in a factory for major IT companies such as IBM, and sold boxed "off the shelf" by those companies or by retail chains such as PC World, or are you also thinking of those built to the customer's order by smaller local vendors? (There is not necessarily a clear-cut distinction between those two categories.) If you include the latter, I'd think it inevitable that, sometimes, used components were/are recycled (unless the builder/vendor makes a specific guarantee of all new components). {The poster formerly known as 87.81.230.195} 2.218.14.51 (talk) 21:49, 27 April 2018 (UTC)
 * I suppose I primarily mean the first category.--Leon (talk) 11:44, 28 April 2018 (UTC)


 * While I have zero doubt that some shady local venders will re-use large componants like video cards in the manner that 2.218 suggests, the problem is more insidious, and will sometimes effect products by big name brands.
 * Simply put, the problem is counterfeit parts. Sometimes the counterfeits are no-name knock-off brands being sold as name brand. (This was the cause of the infamous Capacitor plague) but sometimes the problem is recycled components being sold as new.   Electronics wind up at some recycling center in a nation where labor is cheap, and they remove all the components, sort out the ones worth money, and sell them. If they still look new, they may be resold as new.  Once they're on the market, they could be bought by anyone who needs them. Including respected brands.
 * So just because your video card is new doesn't mean everything on it is new.
 * Of course, the problem is more severe with more expensive stuff, like aerospace components. The military is particularly vulnerable because once they have a well proven design, they tend to stick with it, so they often have need for older model components.
 * Here's an article about it.
 * ApLundell (talk) 06:17, 29 April 2018 (UTC)


 * Many years ago, both Dell and Gateway had issues with putting used/refurbished parts in new computers. That wasn't a real problem. Most people didn't know or care. I only noticed because I opened up hundreds of computers and I saw variations in hardware inside the same model of computer. As long as the computer worked, I did the required upgrade and sent it along. 209.149.113.5 (talk) 10:05, 1 May 2018 (UTC)

Chainsaws and sawdust
I'm watching someone use a chainsaw from a distance; he's facing away from me, so the saw's spitting out sawdust in my direction. Starting to wonder...why does the dust go backward? Here's a chainsaw, with its blade going left and the dust spitting out to the right.

C &macr;&macr;&macr;&macr;&macr; Ɔ█████__________

Why doesn't it go down, or up, or sideways? It makes sense to say that the dust gets carried along by the teeth on the chain, but then why doesn't it continue to get carried around the chain until it reaches the wood again (and then go down, along the piece of wood), or if it falls off the teeth when it comes to the bend, why doesn't it fall off sooner, or at least keep going a little ways and deviate elsewhere along the line somewhere?

Nyttend (talk) 22:29, 27 April 2018 (UTC)
 * Newton's first law of motion. The momentum of the dust is sufficient to overcome any attractive force it had with the blade, so it mostly keeps going on the straight line direction it was already going in. -- Jayron 32 22:43, 27 April 2018 (UTC)
 * So it starts dropping immediately (i.e. nothing's keeping it up at all), and I just don't notice it until later? Nyttend (talk) 03:01, 28 April 2018 (UTC)
 * Well, if the saw is cutting into the wood from the top, then the groove (kerf) that it makes is going to keep the dust from dropping at first. But basically that's a yeah. --69.159.62.113 (talk) 07:48, 28 April 2018 (UTC)
 * When the chain changes direction they part as the dust mantains its direction and velocity (round 70 km/h). It does drop eventually but it is fast enough to fly almost horizontally for a few meters. Beside that the chain accelerates not only the dust but some air around it, which travels together with the dust and helps it to mantain direction and velocity 194.174.76.21 (talk) 15:10, 7 May 2018 (UTC) Marco Pagliero Berlin