Recycled PSUs in Counterfeit laptop power supplies, common or not - Page 1
Forum section: electronics / general

author: Deodand2014
author_rank: Regular Contributor
timestamp: August 19, 2017, 12:07:59 pm
content: First post, so I thought I would start with something interesting, I found two videos on YouTube one dating from 2015 and the other from 2017 covering teardowns of counterfeit ACER power supplies. In both cases the contents of the supplies turned out to be of much higher quality than the average counterfeit, but what it looked like was that someone had recycled an existing power supply into a counterfeit one.In the 2015 video it looks as if the RF shield has been raggedly cut (possibly to allow the capacitors to be replaced.) to make it fit into the box.The 2017 video is slightly different, the only major change to the power unit is what was probably a two pin mains connector has been replaced with a three pin connector that is connected to the mains/neutral tracks by holes crudely punched into the PCB (Why the original connection points were not reused a mystery.), the only clue as to what happened is that the RF shield is actually rusted in places.So it looks like at least some counterfeits are using recycled power supply units rather than 'Wan Hung Lo' cheapies, but you have to wonder just how common the practice is. Has anyone else come across something like this.

author: wraper
author_rank: Unknown
timestamp: August 19, 2017, 01:16:30 pm
content: I recently received one device ordered from China, seller replaced original 9V PSU with US plug with a PSU which has EU plug. Enclosure was pretty flimsy so I easily popped it open. Turned out to be recycled CHINESE USB charger of acceptable quality made in 2007. They even left original USB connector which is now hidden. Also they soldered another resistor on top of feedback resistor to modify voltage output from 5V to 9V.

author: Deodand2014
author_rank: Regular Contributor
timestamp: August 19, 2017, 01:32:35 pm
content: Interesting I suppose it's marginally safer than a 'build-it-yourself' counterfeit but then the end user is at risk from aged components and whatever bodgery was done to recycle the power supply.What was most intriguing about the two videos was that both fake ACER power units actually had much higher quality case build quality than the average counterfeit even though it's quite clear in both instances the power supply components are clearly not in the original case they were supplied in.

author: Kjelt
author_rank: Super Contributor
timestamp: August 19, 2017, 01:52:25 pm
content: It could well be NOS psu that are recycled.Many psus are shipped unused as obsolete stock to the "dumpster country" where they are salvaged for parts.At this moment business laptops have a write off period of three to four years, after that all the accesoiries like docking stations and psus are scrapped unless they fit on newer laptops which sadly is not the case.

author: Deodand2014
author_rank: Regular Contributor
timestamp: August 19, 2017, 02:24:26 pm
content: Quote from: Kjelt on August 19, 2017, 01:52:25 pmExactly, my second hand laptop came with a replacement power supply that is clearly of the China cheapie variety, but my chances of finding a legitimate replacement for a reasonable price is incredibly low.Still this recycling of dumped PSUs adds a new twist to the eBay/Amazon counterfeits story.

author: wraper
author_rank: Unknown
timestamp: August 19, 2017, 04:15:49 pm
content: Quote from: Kjelt on August 19, 2017, 01:52:25 pmI would guess that chances for this are close to zero. Recycled e-waste is orders of magnitude more probable (they have a LOT of that).

author: Zero999
author_rank: Super Contributor
timestamp: August 19, 2017, 04:18:07 pm
content: Quote from: Deodand2014 on August 19, 2017, 02:24:26 pmWell you bought it second hand so it's perfectly legitimate for it to contain used replacement parts, in my book. If it were sold to you as new, then you would have a right to complain.

author: Deodand2014
author_rank: Regular Contributor
timestamp: August 20, 2017, 05:18:02 am
content: Quote from: Hero999 on August 19, 2017, 04:18:07 pmBingo, neither the laptop nor the charger have given me any reason to complain. @wraper, your comment about the sources of the recycled PSUs probably being e-waste is probably spot on. I'm currently trying to track down a video I saw on BigCliveLive where he was tearing down the power supplies for some Chinese decorative lights. You had repurposed (factory rejects?) USB charger cases containing either a mains dropper circuit (non-isolated) or a reasonable looking USB charger power supply (isolated) with the USB connector removed.I found the video in question, dating from 2015, the two power supplies appear at 6:25, he briefly looks at the modified USB charger supply (And talks about reverse engineering it, which he has not yet done.) but the main focus is on the dropper circuit which gets a full reverse engineering.I've also stumbled across two videos he did on solar charged camping lamps which used salvaged(?) mobile phone batteries for power storage rather than standard lithium batteries.Inside a solar charged LED lamp. (2015)Inside a USB and solar rechargeable camping light. (2017)The camping light torn down in 2017 has some dangerous construction issues.

author: fourtytwo42
author_rank: Super Contributor
timestamp: August 20, 2017, 03:45:53 pm
content: The worst problem I have encountered with FAKE psu's is that although stamped CE (for European EMC & safety compliance) I have had several instances where they do not comply, typically they have no common mode chokes nor X & Y capacitors. The reason I investigated as I tracked them down as the source of poor SNR on my broadband connection!

author: thm_w
author_rank: Super Contributor
timestamp: August 21, 2017, 11:08:16 pm
content: Quote from: wraper on August 19, 2017, 04:15:49 pme-waste can consist of a lot of new stock though. We purchase many devices that come with a wall power adapter, the adapter is never used and throw into the recycling.Since its hard to re-use 100 one-off supplies, it would be more likely to me that they have a ton of one type of power supply. Of course it could be used too, if they get a hold of a batch of off-lease laptops as mentioned.

author: Rbastler
author_rank: Frequent Contributor
timestamp: August 22, 2017, 06:26:55 am
content: Quote from: fourtytwo42 on August 20, 2017, 03:45:53 pmChina Export ftw Sent from my A0001 using Tapatalk

author: wraper
author_rank: Unknown
timestamp: August 22, 2017, 10:34:14 am
content: Quote from: thm_w on August 21, 2017, 11:08:16 pmThey are sorting that stuff from a big pile of different garbage. You can even get reballed used BGA ICs sorted by date codes just to sell them as new.

author: Kjelt
author_rank: Super Contributor
timestamp: August 22, 2017, 11:42:13 am
content: Quote from: wraper on August 22, 2017, 10:34:14 amWhat you see there is the waste coming from eu and us electronics recycle factories from individuals and worthless electronics. Not all e-waste is coming from them.Companies have to pay for the ewaste to be processed by recycling factories, I know for a fact that some large electronic (lease) companies ship containers with intact PSU's, dockingstations and laptops to China and even get paid for the transport plus extra.BTW in our recycling factories the coils and transformers are crushed for retrieving the copper wire and no way that you be able to make another PSU out of that garbage.

author: wraper
author_rank: Unknown
timestamp: August 22, 2017, 03:22:20 pm
content: Quote from: Kjelt on August 22, 2017, 11:42:13 amDunno if it is applicable to small SMPS, amount of retrieved copper is tiny compared to the effort required to separate coils from the rest of the circuit considering wages in western countries.

author: Deodand2014
author_rank: Regular Contributor
timestamp: February 23, 2018, 01:24:18 am
content: I was poking around on Youtube looking for teardowns of Ebay 12v power supplies and found another teardown where it seems the interior was repurposed from another power supply.One interesting 'feature' of this recycled power supply is the modification to fit the LED power indicator, it's straight across the filtered output. The connection jack on the other hand is connectedaheadof the filtration choke/capacitors. This means that the LED gets clean filtered power (which it does not need.) and the output to whatever is being powered is effectively unfiltered.The person who makes the video comments that whoever modified the power supply just attached the output to the "...first capacitor they see ..." (00:11:44 - 00:11:51), while I would agree in essence (If I had modified the power supply I would have unsoldered the original cables and used those connection points for the new connectors...), but there may have been a simple reason for that change, if the output connection and the LED were both connected at the same point, the LED would vary in brightness depending on the current draw.One good thing about this video is the maker gives a full schematic for what he has torn down, which means it might be possible to replicate the circuit for testing.

author: Nauris
author_rank: Regular Contributor
timestamp: February 23, 2018, 06:43:08 pm
content: Quote from: wraper on August 22, 2017, 03:22:20 pmThere are actually nice methods to retrieve that copper with minimal labour.There is a company (Boliden Harjavalta Oy) not too far from me that mixes crushed circuit boards with copper ore and sends it thru flash smelting process. Sounds crude but it is suprisingly efficient process.First plastics portion burns and provides energy for the process (and for district heating) then glass fibre in FR4 works as slag former replacing some part of the sand otherwise needed.Copper obviously adds to copper reduced from ore. Any precious metals (like gold) and for the most part any less reactive metals (like tin or lead) dissolve in the copper. Only more reactive metals like iron and aluminium are lost to slag. Copper is then electrolytically refined in the usual way separating copper and metals dissolved in it. End result is pure copper and sludge/electrolyte that is further processed to recover metals in it.It is quite large scale operation (last figures I found) with currently about 30 000 tons of circuit boards and other copper containing waste processed per year and with capacity for 145 000 tons/year.Just imagine how many usb power supply pcb's there is in mere 1 ton.

author: Kjelt
author_rank: Super Contributor
timestamp: February 23, 2018, 08:12:44 pm
content: That is good to read, IMO the EU and other countries should all recycle their own waste.

author: Deodand2014
author_rank: Regular Contributor
timestamp: January 23, 2019, 02:56:22 pm
content: I've located the teardown photographs and schematics for the 12v '5a' (Actually 3 amp) power supply made with a recycled PSU that Diode Gone Wild tore down. I've linked it below.http://danyk.cz/reverz41_en.htmlHe's also done a video recently on a PSU that contained components that may have been recycled from E-waste, some incredible construction errors and apparently is built from a schematic reverse engineered from an AT power supply, it even includes a redundant fan header...

author: station240
author_rank: Unknown
timestamp: January 24, 2019, 11:22:43 pm
content: Quote from: Deodand2014 on February 23, 2018, 01:24:18 amI find the RC network across the output rectifier unusual, as is the common mode choke on the output.Not seen this in a simple SMPS, ATX PSUs have a common mode choke all the output rails pass thru.Actually I was going to post that DiodeGoneWild video, but you found it first.

author: james_s
author_rank: Super Contributor
timestamp: January 25, 2019, 12:54:39 am
content: I'm all for reusing, it's by far the most efficient form of recycling. What bothers me is when an item is presented as something that it isn't. Don't stick a brand label on something and sell it as genuine if it's an aftermarket part. Sell it as high quality compatible with xyz brand and that's fine.

author: wraper
author_rank: Unknown
timestamp: January 25, 2019, 01:30:27 am
content: Quote from: station240 on January 24, 2019, 11:22:43 pmIt's not a common mode choke, and it's not a common mode choke in ATX PSUs. ATX PSUs use transformer with iron powder core to achieve group stabilization of different output voltages.

author: Deodand2014
author_rank: Regular Contributor
timestamp: January 25, 2019, 08:38:03 am
content: Quote from: station240 on January 24, 2019, 11:22:43 pmIn the comments to his most recent teardown (The 24V 10A 240W power supply unit), he's indicated that the power units schematic is based off AT power supply, right down to how the IC powers up. Also in that teardown he points to both the right way to use eWaste and the wrong way, with the PSU being supplied with unmatched transistors (Apparently they have different datecodes) in the halfbridge, when he repaired it he used salvaged components from a junked computer power supply.It's quite possible that Chinese manufacturers are reverse engineering computer PSUs to design their SMPSs and other power supplies, I'm just surprised they'd go as far back as the AT.There is also this teardown, no sign of recycled components, but it looks as if the board was configured with spaces for extra items including an X class capacitor before the bridge rectifier, two other capacitors one of which appears to have been for a class Y. 3 resistors where only a single large resistor has been used and a fan header,http://danyk.cz/reverz44_en.html

author: Deodand2014
author_rank: Regular Contributor
timestamp: February 12, 2019, 02:45:43 am
content: Diode Gone Wild has posted his discussion of the schematic (Drawn by his cat...) of the 24v 10a power supply and what modifications are needed to improve it's efficiency, beyond what was done in the last video.

author: Deodand2014
author_rank: Regular Contributor
timestamp: March 31, 2019, 02:18:36 pm
content: For anyone interested, here is the schematic of the 24V 10A 240W from my previous postshttp://danyk.cz/reverz45_en.htmlThere are two versions, the first is what was shown in the video, the second is a cleaned up version. Perfect for anyone thinking about building their own, just remember to put the fuse on the live not the neutral...