DIY Chatroom Home Improvement Forum

DIY Chatroom Home Improvement Forum (
-   Electrical (
-   -   Modifying laptop ac adapter - Confused. (

miller108 03-31-2010 12:53 PM

Modifying laptop ac adapter - Confused.
I can provide pictures if I don't describe this well enough. Basically what I aimed to do was create a custom laptop ac adapter for a used laptop I just came into possession of. I have an adapter from my current laptop that just so happens to be the same ac input/dc output requirement of the one I need. Problem was, it doesn't fit into the hole. My genius idea was to snip the end off the current adapter and solder on an adapter end piece I found that DOES fit (lit up the new laptop's plug as well, just wasn't enough to turn it on) My problem came when I stripped both down. My current laptop ac adapter is one solid wire wrapped in plastic, which has a wire mesh wrapped around that and of course the outer plastic wrapping. The adapter piece I found that I was going to go with it has two seperate wires which I can only assume is - and +. One side is black, the other is black with a white stripe running down it. I figured the inner workings of a power cable of this type would be the same, but I was clearly wrong. My question comes down to..what do I solder together from each cable to get it working, if this is at all possible. I'd rather not blow a fuse or fry the laptop. Thank you :)

brric 03-31-2010 01:11 PM

Without further investigation the best guess is the center conductor goes to the center of the jack and the outer braid goes to the other contact.

after rereading.
black to center conductor, black/white to the braid

miller108 03-31-2010 01:36 PM

That absolutely did it! Works like a charm :D Thank you so much for the quick reply!

Ocelaris 01-14-2013 08:02 AM

* note spam post above was removed *

Besides being a borderline advertisement above. As an IT guy, I'm not a big fan of universal power supplies. Mostly because people don't realize the different voltage/amp requirements that they need for various laptops. Also I've found the universal ones tend to skimp on the amperage and/or build quality, and tend to fry. That's not to say that you can't find a reasonably good one, but you need to be sure your DC voltage/amperage matches what the laptop says it needs (usually stated on the bottom of the laptop), or it defiantly says on your OEM power supply.

On the other hand, I would never purchase a mac power supply because they're horrendously over priced, like all mac items. So this would be a good case for an after market power supply. Some Universal power supplies are fine, but there are also lots of junk out there too. And this is inherent in the reason "switching" power supplies can be junk, cheap parts, noisy oscillators, weak capacitors, poor heating dissipation. If you're paying a premium for a power supply, make sure it's from a reputable brand and the specs are up to snuff.

To the original poster, I've hacked hundreds of power supplies, sounds like you figured it out, just always look for the note on the pinout whether center pin or outside is positive/ground. If you don't see a note about which is positive/negative, typically ground is always the connection that "first makes contact" when you plug it in. This is to dissipate static charges, so if you don't have a guide, this usually is the case. Pretty much all modern >1980 connections make sure to touch ground before power (SATA, USB etc...) for that reason. Next time you look at a connector, look for the pin that touches first, 90% of the time it's ground. Which is why RCA is a bad connector (signal =middle pin and touches first).

DangerMouse 01-14-2013 08:25 AM


Originally Posted by Ocelaris (Post 1093083)
Besides being a borderline advertisement above.

Borderline? No, spam.... plain and simple. :laughing:
Gone and banned.


jbfan 01-14-2013 08:35 AM

And a 3 yo thread!

Ocelaris 01-14-2013 08:46 AM

doh... oh well. Thanks for picking that up.

DangerMouse 01-14-2013 08:49 AM

No problem, your info was valid. :)


All times are GMT -5. The time now is 02:52 PM.

vBulletin Security provided by vBSecurity v2.2.2 (Pro) - vBulletin Mods & Addons Copyright © 2017 DragonByte Technologies Ltd.
User Alert System provided by Advanced User Tagging (Pro) - vBulletin Mods & Addons Copyright © 2017 DragonByte Technologies Ltd.

Search Engine Friendly URLs by vBSEO 3.6.1