laptop power adapter replacements - Page 1
Forum section: electronics / beginners

author: LaserTazerPhaser
author_rank: Regular Contributor
timestamp: May 16, 2019, 12:21:07 am
content: Can a meanwell or some other quality adapter replace an OEM laptop adapter if the output voltage and current meet or the current exceeds the OEM adapter?

author: Richard Crowley
author_rank: Super Contributor
timestamp: May 16, 2019, 12:34:18 am
content: Does your mystery load (your unidentified laptop) use a simple 2-pole connector (implying that it operates at a fixed power: voltage/current)? Or is it something with a more sophisticated arrangement where it negotiates voltage/current with the supply?If it is a simple 2-pole connector, then it seems likely that any supply of proper voltage and sufficient current will work OK.Of course it is absolutely mandatory that you get the polarity correct. Else, you will likely toast your laptop as most don't have polarity protection.Clearly, a fixed-voltage source isn't going to work properly with a load that expects to negotiate the voltage/current. This is difficult to answer properly as a generic question.

author: CJay
author_rank: Super Contributor
timestamp: May 16, 2019, 09:48:11 am
content: As Richard says, some laptops use electronic 'serial numbers' to verify genuine or not so your lapotop may decide it's not a genuine AC adapter and refuse to charge.I think you could probably get away with using a Meanwell supply, they seem to be generally OK but beware of cheaper supplies, I've seen significant problems with some cheap adapters which cause very odd symptoms on the laptops they're powering (USB ports not working, noise on audio, random lockups) which disappeared when a genuine adapter was used.

author: GigaJoe
author_rank: Frequent Contributor
timestamp: May 17, 2019, 03:28:30 am
content: electronic 'serial numbers' ?or just resistor on third pin

author: Richard Crowley
author_rank: Super Contributor
timestamp: May 17, 2019, 04:09:13 am
content: USB-C power has four different power (voltage/current) settings. As negotiated between the load and the supply.Three of them are standardized at 5V, 12V and 20V (at various currents) plus an additional mode for specialized gear.Ref:https://en.wikipedia.org/wiki/USB_hardware#USB_Power_Delivery_(USB_PD)And, as @GigaJoe mentioned Apple started the standard of fixing the two data pins at various voltages to indicate the voltage/current capability of the supply.

author: oPossum
author_rank: Super Contributor
timestamp: May 17, 2019, 05:33:41 am
content: Quote from: GigaJoe on May 17, 2019, 03:28:30 amApple, Dell and HP use Dallas/Maxim one wire devices for adapter capability info and in some cases (mostly Apple) to drive status LEDs.

author: CJay
author_rank: Super Contributor
timestamp: May 17, 2019, 08:03:39 am
content: Quote from: blueskull on May 17, 2019, 06:32:17 amI didn't claim they did 'authenticate'.Dell machines used to include a Dallas one wire device, I think it was in the D600 series laptop PSUs that I first saw one (when Win XP was new), memory tells me it was an electronic serial number or ID tag but I really can't remember the part number any more, however, if the part was damaged or disconnected somehow the laptop would power up but refuse to charge.I *think* I may have a faulty Dell one here which I could disassemble and take pictures ofHP adapters use something similar.Lenovo use a simple resistor to identify adapter capability.Apple are a protectionist world of their own.Again, I'm a fan of the low prices the Chinese manufacturers are able to bring to the market, I'm not in any way knocking clone PSUs, most are perfectly adequate and work as well as the original, just passing on a warning from my experience that some of them are really poor and can cause 'odd' problems.

author: CJay
author_rank: Super Contributor
timestamp: May 17, 2019, 09:22:05 am
content: Quote from: blueskull on May 17, 2019, 08:08:18 amThen I bow to your superior experience, I've seen some of the things you've posted here and admire your skills.Maybe I should have said counterfeit instead of clone because I'm in agreement with you, the 'name brand' certified adapters are OK, it's the ones made up and labelled as original or to look so close to the OEM as to be indistinguishable at first glance that are generally crap.

author: Richard Crowley
author_rank: Super Contributor
timestamp: May 17, 2019, 09:31:31 am
content: My laptop computer at the office uses USB-C for power. It requests the 20V mode from the power supply. It also uses USB-C to the docking station where I have four displays connected along with keyboard, mouse, etc. And a USB headset and Skype for Business (since they took away all the phones).

author: CJay
author_rank: Super Contributor
timestamp: May 17, 2019, 12:03:02 pm
content: Quote from: Richard Crowley on May 17, 2019, 09:31:31 amWe're starting to see machines that use USB-C here too, I believe most of the HP ones we provide now can use it but come with a 'standard' PSU socket and adapter, the HP tablet PCs definitely use it and don't have a 'standard' power socket.

author: wasyoungonce
author_rank: Frequent Contributor
timestamp: May 17, 2019, 12:26:07 pm
content: If you adaptor died they are easy to repair, mostly it’s the DC power lead. They can be difficult to take apart. I use hot knife and re-melt them back together.Most Chinese knock off adaptors are very poor quality if not downright dangerous. I tried a few and after looking inside them....never again.Sent using iPhone

author: LaserTazerPhaser
author_rank: Regular Contributor
timestamp: May 18, 2019, 07:40:22 am
content: Quote from: wasyoungonce on May 17, 2019, 12:26:07 pmAren't many bricks potted for greater thermal transfer?Quote from: Richard Crowley on May 16, 2019, 12:34:18 amSeems only Mac bares those elongated multi connecting charging plugs for laptops. I was referring for ordinary 2 pole connectors.USB type C should really be replacing these things especially with the availability for magnetic type c adapters. With the great burden of backwards comparability with USB Type A which Type C must operate with - counterfeits are very much in position to do great damage to consumer goods with their faulty, unreliable or inoperable components with which their likely to be constructed with.

author: wasyoungonce
author_rank: Frequent Contributor
timestamp: May 18, 2019, 07:56:05 am
content: Aren't many bricks potted for greater thermal transfer?Some are most not. Most use a white silicon type potting on bigger components for mechanical stress. It’s easy to pick off. Most bad adaptors have bad connectors it’s usually easy to access the pcb to replace this as it’ll be soldered right at one end edge.Sent using iPhone

author: radiolistener
author_rank: Super Contributor
timestamp: May 18, 2019, 10:48:26 am
content: Quote from: blueskull on May 17, 2019, 06:32:17 amMost of Chinese cable are very bad for power supply. They has too high resistance which leads to high voltage drop and power loss. Also they bad soldering and requires to use acid in order solder it.I recommend to buy some good cable from real copper instead of Chinese silumin cables named as "copper".

author: LaserTazerPhaser
author_rank: Regular Contributor
timestamp: May 19, 2019, 07:03:07 am
content: Meanwell bricks aren't potted?

author: LaserTazerPhaser
author_rank: Regular Contributor
timestamp: May 19, 2019, 10:27:31 pm
content: Quote from: blueskull on May 19, 2019, 07:11:31 amMeant potting as components are no longer accessible since entirety of open space is filled with epoxy.

author: LaserTazerPhaser
author_rank: Regular Contributor
timestamp: May 20, 2019, 03:16:48 am
content: Quote from: blueskull on May 19, 2019, 10:35:48 pmAre there any blogs or similar sites showcasing meanwell or another reputable power supply such as TDK lambda brick board and components?

author: Richard Crowley
author_rank: Super Contributor
timestamp: May 20, 2019, 05:01:27 am
content: If you want top-of-the-line power supplies (and are willing to pay the top-of-the-line prices) you can look athttps://www.acopian.com

author: TimNJ
author_rank: Super Contributor
timestamp: May 21, 2019, 12:58:29 am
content: Quote from: blueskull on May 20, 2019, 05:08:30 amThis is one of my favorite sites! The tend to showcase mostly Chinese brands, which may OEM for some "American" brands.I have no problem with Meanwell. They sell *a lot* of power supplies, which means they can actually make a decent quality product at a reasonable cost.It's when you buy the eBay no-name, no-regulatory-marking adapters that you run into trouble.

author: Liam
author_rank: Newbie
timestamp: May 21, 2019, 05:36:21 am
content: The most logical in this situation to contact the manufacturer or their technical support. Remember the cost of a mistake can cost the life of your computer.

author: LaserTazerPhaser
author_rank: Regular Contributor
timestamp: May 21, 2019, 08:00:32 am
content: Quote from: TimNJ on May 21, 2019, 12:58:29 amThere aren't any posts showcasing meanwell wall mounted or desktop adapters.