The Your Tech Weblog (whose author really needs to provide some bio information) recently served up this mini-rant, which I found courtesy of Ernest Miller at Corante:
My current tech pet peeve: gadget power adapters that aren’t properly labeled.
An iRiver AC adapter, for instance, should read “iRiver” somewhere on its surface so it’s more easily associated with an iRiver music player. For tech journalists or geeks with multiple gadgets, this is a potentially nightmarish situation.
PalmOne, for shame; Sony-Ericsson, kudos; etc.
I understand how this happens. Cost-conscious hardware makers buy generic power supplies from low-cost providers. If they have the same power supplies custom made, including the company name and logo, the price goes up. A company that is struggling to be profitable or to avoid losses is going to be tempted to shave 50 cents off the cost of every device as a way to keep its bottom line under control.
The rest of this item contains a solution to this problem, a piece of troubleshooting advice that can help you match a generic power supply to its device, and a bonus tip that might help you reduce the number of power supplies you have to deal with.
Solution: Add your own labels to power supplies. When I get a new device that includes its own AC adapter, I slap a small sticker on it and use a Sharpie to write the device name. (The small labels for file folders usually work well for this purpose.) Update: The PC Doctor notes that the adapter block can get hot and cause the adhesive on the label to give up; he recommends attaching the sticker to the power cord instead.
Troubleshooting advice: Every AC adapter has to be labeled with some key information, which can help you sort out which device it goes with. You may need a bright light and a magnifying glass to read this information, but it’s there. Look for the following data points:
- Input voltage. Most devices manufactured today for worldwide markets accept 110-240V AC, 50/60Hz, which means they can be used in just about any country with the proper plug adapter.
- Output voltage. This will be expressed as a measurement in volts DC. The adapters for my Audiovox SMT5600 phone, my iRiver H120 music player, and my wife’s Creative Zen Micro all put out 5V DC. The battery charger for my Canon S500 digital camera puts out 4.2V DC.
- Output current. This will be expressed in amperes or milliamperes (typically abbreviated A and mA, respectively). The labels on the adapters for the four devices I listed above show output currents of 1A, 2A, 1000mA, and 0.7A, respectively. (Note that 1A is the same as 1000mA, and 0.7mA could also be expressed as 700mA.)
Update: The PC Doctor recommends checking the polarity of the output jack as well. He has a good diagram here.
Armed with that information, I can check the technical specifications section of the manual for my device (Look it up online if you can’t find the printed manual) and find out what its input power requirements are. Those requirements, not surprisingly, should be a perfect match for the output of the power supply. When you find a generic power supply whose power output specs match your device’s input requirements, with a plug that is compatible with the jack on the device, you’ve got a winner. Slap a label on it.
Caution: Don’t assume that any AC-to-DC power converter with a matching plug will work in your portable device. Plugging in a mismatched converter is the surest way I know of to destroy a valuable device.
Bonus Tip: Don’t carry around multiple power supplies if you don’t need them. My wife’s Creative Zen Micro and my Audiovox SMT5600 Smartphone have custom power adapters that carry the company’s logo. But each one has absolutely identical power output specs (5V at 1000mA) and identical USB connectors. I can plug the music player into the phone’s power supply, or vice-versa.
Likewise, the adapters for my iRiver music player and my Creative Labs portable speakers are functionally identical. So, on my recent trip to Europe I carried only two power supplies for these four devices. After the music player was fully charged, I unplugged it and plugged in the phone. That simple step cut the hassle of carrying adapters (and constantly plugging/unplugging them) in half.
Ed Bott 
I’ve been mostly pleased with my iGo adapter that will charge my laptop and cellphone (or camera) simultaneously. They sell “tips” for most common devices, so it is a matter of selecting the right size from the guide. When I travel I only have to carry one power adapter since it AC/DC and works 110 – 240.
With regards to your tip #1, I’ve found that silver colored Sharpie’s work well for writing on the black plastic of the power adapter. Putting the label on the wire is a very short term solution — after a few days in a laptop bag and the labels tends to disappear. These days the first thing I do with a new “wall wart” is label it with the device that it services.
Help!!!, i just bought a super pc with these components:
M/B: MSI P4N SLI-FI
Processor: Pentium D 830 Dual Core 3.0 Ghz
2 Ghz (2 x 1 Gb) Ram DDR2 667 Mhz Corsair
Graphics card: eVGA eGeForce 7900 Gtx 512mb
Hard Drive: WD sata 250Gb 16mb buffer
and a Thermaltake Armor Full tower chassis.
So here´s the problem: for this enormous pc i got a 800w Agiler Power supply and when i was running Age of Empires III in full graphics it just turned off!!!. the pc won´t start again. Not really convinced of what it was i bought the same PSU and it turns out that failed again, my pc doesn´t turn on and now i have 2 burnt PSU, so the question is: ¿how can i fix this?????