Need help/ideas for laptop charger repair!

ads295

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Sep 25, 2015
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Hello everyone. This would be my first post at AnandTech. It was after I went through the website that I realised this would be one of the few places I'd ever get a reasonable response to my post.
So. I own an ASUS laptop that's around 2 years old. I've used the laptop with a lot of care, and most of the time I used it heavily solely on adaptor power, almost always removing the battery.
Now my charger is showing problems, as you can see in the video I made here. I took to the scientific method of thinking of what the problem could be.

I strongly feel the problem is only near the grommet of the adaptor, with the wire, and not a fault of the adaptor itself. I took it to the authorised service center and the joker of a technician looked at it for 5 seconds and said, "This needs replacement!" and quoted a price of about US$100.

It started randomly, and how it manifested was that I could boot the laptop easily, but the laptop would immediately switch off during very particular load scenarios (it would always shut down at a race start in NFS Shift, for example). I had no battery in the thing so it would keep switching off. I thought it was a heating problem so I logged the temps (I'd just opened it up, cleaned it and put fresh thermal compound paste on the CPU and GPU). No problem there (my laptop gets pretty hot during gaming, but then it had barely touched 80°C.) If I left the battery inside, the laptop would apply power profiles for battery power momentarily (charging LED would go off as well) during that starting scene in NFS Shift, and then everything would become normal again as the race started.

The problem, I think, is that the wire has frayed or something and can't conduct as much power as it could. For instance, now it has worsened and I can barely boot the laptop. If I open Chrome the laptop shuts down (I have an i7-3610QM [45W TDP] coupled with a Samsung EVO SSD) due to the momentary load (CPU hits 90+% for a few seconds for the first time). Also, it seems to depend a lot on how the wires are oriented in space (see video). If I get lucky sometimes it runs without any problems at all (for Chrome usage, not gaming obviously).

Now this is all my speculation. I need your expertise to understand, am I thinking wrongly here? If I'm not, how can I repair this? There are generic tutorials online but I'd like to get an idea of how much prior experience working with electronics is needed - I have zero. I thought of snipping off the wire at the base after opening the charger, but how does one put it together again? I don't even know soldering (which, by the way, seems pretty weak).

I really don't want to spend on a new one, and this issue is many months old already - I've resorted to playing older games that work under the ASUS battery saver profile where I've limited the CPU to 1.2Ghz, with passive cooling policy (anyway I guess Active would be suicidal for the Ivy Bridge CPU, it hits 90-100°C in Passive mode :eek:). It's a charger rated for 125W.

I tried to provide as many details as I could, but please let me know if you need to know more :)

Thanks!

Aditya
 

corkyg

Elite Member | Peripherals
Super Moderator
Mar 4, 2000
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You missed the most important piece of data - the laptop model number.
 
Feb 25, 2011
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If you have no electronics expertise, and don't know how to solder, you are going to need to pay somebody else to fix it - which means replacing the adapter with a new one is probably your cheapest option anyway.

Power adapters can definitely "age" - particularly with the high demands placed on them by a gaming laptop running full tilt. An adapter that for some reason wasn't quite as good as the adjacent ones on the assembly line will degrade over a few months, and either not be able to keep up with the current demands, or produce too much heat, and eventually start shutting itself off to protect itself. I had a similar problem with the power adapter on my Macbook - a replacement solved the problem.

It is possible.that a frayed or cat-chewed-on-it power cord could cause the symptoms you describe, in which case soldering in a replacement would fix it. But it would be pretty obvious on external inspection. (There'd be holes and stuff in the cable/insulation.)
 

ads295

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Sep 25, 2015
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eBay isn't really an option - eBay India is very limited in it's scope and doesn't have chargers for my laptop. I was offered a "replacement" (read non-genuine) charger for around half the price, which I didn't take.
My laptop's model number is K55VM-SX086D. Running stock (and hot) except for the SSD put in.
I'd like to continue using this at least until it gives out, then, but I doubt the charger will be available for very long, given the model is old.
 

ads295

Member
Sep 25, 2015
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If you have no electronics expertise, and don't know how to solder, you are going to need to pay somebody else to fix it - which means replacing the adapter with a new one is probably your cheapest option anyway.

Power adapters can definitely "age" - particularly with the high demands placed on them by a gaming laptop running full tilt. An adapter that for some reason wasn't quite as good as the adjacent ones on the assembly line will degrade over a few months, and either not be able to keep up with the current demands, or produce too much heat, and eventually start shutting itself off to protect itself. I had a similar problem with the power adapter on my Macbook - a replacement solved the problem.

It is possible.that a frayed or cat-chewed-on-it power cord could cause the symptoms you describe, in which case soldering in a replacement would fix it. But it would be pretty obvious on external inspection. (There'd be holes and stuff in the cable/insulation.)

But then what would you have to say about the video I posted? It clearly shows how a certain cable position assists the problem significantly.
It ran for a few months, and I'm sure it can run for a few more. I think learning soldering is doable before it dies - how much would I have to invest for that? I'm inclined to believe there is something that can be done with this charger and I'd hate to see it turn into e-waste.
 
Feb 25, 2011
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But then what would you have to say about the video I posted? It clearly shows how a certain cable position assists the problem significantly.
It ran for a few months, and I'm sure it can run for a few more. I think learning soldering is doable before it dies - how much would I have to invest for that? I'm inclined to believe there is something that can be done with this charger and I'd hate to see it turn into e-waste.

Video won't load.

If you are wiggling it and think there's an improvement, it's probably in your head. If, OTOH, you can turn the computer on and off by adjusting the cable a certain way, then by all means replace the power cable if you can do so.

They're not typically designed to be user serviceable though.
 
Feb 25, 2011
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I'd like to continue using this at least until it gives out, then, but I doubt the charger will be available for very long, given the model is old.

Generic chargers will be around for a long time. As long as you can find one with sufficient amperage, the connectors are generic (they just come in different sizes, and make sure it's center-pole positive/negative to match what you've got).

I've gotten "new" power adapters for 20-30 year old equipment without trouble. You just have to know what you're shopping for. :biggrin:
 

ads295

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Sep 25, 2015
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Video won't load.

If you are wiggling it and think there's an improvement, it's probably in your head. If, OTOH, you can turn the computer on and off by adjusting the cable a certain way, then by all means replace the power cable if you can do so.

They're not typically designed to be user serviceable though.

I have mailed the video to the ID on your public profile. Hope that helps, it is EXACTLY about the wiggling.

If replacement chargers are of good quality, does that mean I can buy one with a lower current amperage and charge slower? That would be awesome, I'm dying to try it out after doing so on my phones.
 
Feb 25, 2011
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I have mailed the video to the ID on your public profile. Hope that helps, it is EXACTLY about the wiggling.

That still leaves you with replacing the power cable. You've already pointed out you're not qualified to do this yourself, and the adapters are not designed or intended to be repaired - only replaced. Which means most techs will flatly refuse to do what you want.

If replacement chargers are of good quality, does that mean I can buy one with a lower current amperage and charge slower? That would be awesome, I'm dying to try it out after doing so on my phones.

No. If the laptop draws more current than the adapter can provide, the adapter will, best case, shut itself off. Worst case it will catch fire or damage your laptop.

Phones are smart enough to turn down the draw when they detect they are plugged into a lower-capacity power adapter. Laptops don't have that option.
 
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ads295

Member
Sep 25, 2015
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Since you can replace the A/C adapter charger for your Asus laptop for $10, why bother trying to repair?

http://www.newegg.com/Product/Product.aspx?Item=9SIA3E41JR8957

Doesn't ship to India, my friend. :$ Also, how on earth is this one rated for only 65W? It has half the current my original charger outputs - in context to what is discussed above, is that safe?
I'll ask my friend from the US to get it whenever he does come, though. Thank you.

SO it's set in stone - replacement it is. I'll tinker around after I get a replacement, maybe open this one up and take a look.

Thanks guys!
 

NAC4EV

Golden Member
Feb 26, 2015
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just bought one for my Toshiba on fleabay $5.00 and its higher capacity
 

ads295

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Sep 25, 2015
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+1 Spend a few bucks and buy a new unit.
I wish the question was just about a few bucks, though. This charger is 65W and doesn't ship to my place.
And $100 in my currency is a LOT of cash to spend.
 
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VirtualLarry

No Lifer
Aug 25, 2001
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Not an uncommon rating for a gaming laptop power adapter. I have a few 90w and a 150w kicking around here for some projects that don't exist anymore.

I was saying that in the context of corkyg's post directly above that. If you click corkyg's link, it shows a 65W adapter, for that same laptop model number.

Why the OP would have a 125W adapter, but the generic replacement would be only 65W, I don't know. That might be an issue, if it actually needs a 125W adapter.
 
Feb 25, 2011
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I was saying that in the context of corkyg's post directly above that. If you click corkyg's link, it shows a 65W adapter, for that same laptop model number.

Why the OP would have a 125W adapter, but the generic replacement would be only 65W, I don't know. That might be an issue, if it actually needs a 125W adapter.
Oops, missed that part.

Yeah, no. Probably not going to fly.
 

ads295

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Sep 25, 2015
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My apologies if this thread bump gets in the way, but my friend agreed to get a charger for me!
Now I need your help - what is a good place to buy chargers in the US? My friend is a regular at Amazon and I came across this unit:
http://www.amazon.com/Extra-Adapter...-3&keywords=k55vm&refinements=p_72:1248879011

I also did a search and ended up at Newegg with this:
http://www.newegg.com/Product/Produ...JR8957&cm_re=k55vm-_-9SIA3E41JR8957-_-Product

Now I have absolutely no idea about these aftermarket charger brands - anyone here who can recommend what's trustworthy? I know my charger is rated for 125W, but I think I'll get by with a 90W charger if I don't plug in my battery (I'm assuming a significant portion of the power is used to charge it while sustaining heavy loads). The Newegg charger is 65W so definitely planning to avoid that (I wonder why they specifically decided to specify K55VM-SX086D, my exact laptop model number, when the charger is rated for half the power.)

Thus I plan to use the old charger when plugging in the battery/gaming, and use the newer one for everything else.
 

myocardia

Diamond Member
Jun 21, 2003
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A 90w charger should be plenty, especially if you aren't trying to charge the battery while you put the CPU under full load. And the charger you want to use while gaming is the new one, not the old one. Let the battery fully charge first, then start the game, or remove the battery before you start gaming. I wouldn't use the $9 one being sold through newegg, if you gave it to me for free (newegg is NOT selling that one, nor are they guaranteeing it will work at all with your laptop, btw).
 

ads295

Member
Sep 25, 2015
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Thank you! I'll mostly go for the Amazon charger instead. If anyone else has comments to make otherwise, please do!