Worst luck or something more troubling?

July 18, 2011 4:37 PM

Is there something causing my laptop's power supply to fail?

I have a fujitsu convertible laptop and about two weeks ago the power supply just died. I got a new one (third party) and all seemed right as rain until today when the new one died. The company is shipping me a new (supposedly better) one toute suite, but I just dont want to go in circles if the power supply is not the real problem. Do I have just incredible bad luck or is there a problem with the laptop? Will provide more information if requested. Suggestions on fixes would be appreciated as mr. Boobjob is a computer wiz (though currently at work, driving me to query the hivemind).

posted by boobjob to Computers & Internet (6 answers total)

Does the power cord work if it's jiggled around a bit? Does the converter box get warm when it's plugged in? From my experience with laptop power supplies, these are where the connection fails, most often right where the cord plugs into the laptop. If that's bent too much, the connection fails. You could try taping up the cord near the laptop connection point, to strengthen the cord in this area and increase it's life.
posted by filthy light thief at 4:45 PM on July 18, 2011

It is highly unlikely that the laptop is somehow causing the power bricks to fail. They're probably just badly made. I suppose you could have a power issue; have all three failed at the same outlet?
posted by goblinbox at 4:47 PM on July 18, 2011

There could be an external problem. There's one outlet in my apartment that I dubbed "the outlet of death"--my power adapters would always die after a few months until I stopped using that outlet to charge the laptop. I assume that outlet was just getting power surges (the electric wiring in our 90-year-old building isn't that great). Maybe consider a good surge protector?
posted by phoenixy at 4:47 PM on July 18, 2011

Response by poster: So the reason I believe it is the power supply rather than the connection is that the led on the brick began to turn on and then go dim and then dark and now it will not light at all. No finagling with the connection to the laptop has had any effect (I mean nothing, no millisecond long flashes). I use a lot of outlets in a lot of places so I couldn't really say if one of them is doing it. I will say that the exact outlet I was using the first time it went bad is not the same one as today's failure and is not even in the same house. However, I'm not sure if this is the kind of thing that wouldn't take effect right away, in which case the outlets were the same: time 1 I had been using this outlet for several hours and then supply died, time 2 computer was charging at this outlet for a while, I unplugged, drove to new location and within minutes the supply started to die.
posted by boobjob at 5:08 PM on July 18, 2011

A laptop battery with a shorted cell can kill power bricks. A badly soldered connection to the motherboard, behind the female power supply jack, can cause no power to be transferred from the power supply to the machine. A bad DC-to-DC converter module on the motherboard can pull excess power from the power brick, causing it to fail.

The definitive test for the power supply is to unplug from the laptop, plug it into the wall, and check that it outputs its rated voltage with a DC volt meter. Then connect it to the laptop, and see if it is supplying rated current to the laptop, using a DC ammeter. Many local computer repair shops make a little test jig with resistors that does both load tests at once, and will check out your power supply independently for free.
posted by paulsc at 5:23 PM on July 18, 2011 [1 favorite]

The third-party power supplies for a lot of laptops are *crap*. I have gone through *seven* for my netbook. Fortunately, the seven cheap ones have in fact cost less than *one* of the brand name, and the brand name one only lasted a year (and the seven's been over the two years since) so I feel like I'm doing pretty okay.

Not that there can't be internal problems, but the companies that make the knockoffs just don't make them very well.
posted by gracedissolved at 7:22 PM on July 18, 2011