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How’d They Make That 2 May 11, 2009

Posted by laptoppartsexpert in AC Adapter, DC Jack.
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After discussing the makeup of a battery, I thought I would do the same with AC Adapters. Unlike batteries, AC Adapters are very straightforward in that there are only a few different types. Usually, you will see a fixed voltage of 15V, 16V, 19V, 20V or 24V. Sure, there are a few odd ones like 15.6V for Panasonic or 18.5V for some Compaq/HP or 19.5V for Dell or Sony. The formula for AC power is simple:

Voltage x Amperage = Wattage

Now, let’s talk about why this is important. You must use an adapter with your laptop or netbook that is +/- 1V from the recommended voltage on your unit. In addition, the minimum amperage required for the laptop to get power at the specified voltage is the amperage the laptop will pull from the adapter. For example, if you have a laptop that is 19V, 3.42A, a 65W requirement, and you use the corresponding adapter, the laptop will get the power that it needs. If you use a 90W, 19V, 4.7A, the laptop will pull 3.42A of the 4.7A available. There are some manufacturers like Acer that offer the 90W because they say it is a rapid charger for the battery. Other manufacturers like Toshiba offer a 90W adapter because they have sold out of the older 75W version. However, if you have a 90W laptop that requires 4.7A of power and you only give it 3.42A, the laptop will pull 4.7A out of the available 3.42A and the adapter will burn up over time.

Over the years, I have seen HP ship a 90W adapter for a laptop that needs a 135W and the result is a bad adapter after a few months. Some laptops have a safety feature that will not allow the laptop to turn on if it does not have the proper power available.

The next step in matching an adapter is to confirm the polarity of the tip, usually center positive and match the pin size of the adapter to the DC Jack you plug it into. It is important to note that since DC Jacks have become available, many people have replaced jacks that have the same footprint as the old jack but have a different size center pin. This means that you may try to get a replacement adapter that will not match. In this case, you have to measure the pin size to get a match.

One more warning. If you have get a universal adapter, you need to make sure it has a fixed voltage for your laptop. Many of the major brand universal adapters go from 15V-24V and have a tip that regulates the voltage based on the laptop you are plugging it into. However, if the tip goes bad, you end up with 24V shooting into your laptop which will do major damage to your laptop. If you need an adapter custom made and you have the voltage, amperage, polarity and pin size, we can usually have it made in a couple days. You can email us at info@laptoppartsexpert.com.

Sony AC Adapter and Jack Issue April 29, 2009

Posted by laptoppartsexpert in AC Adapter, DC Jack.
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I got an email from a customer today that said he was returning an AC Adapter to us because it did not fit in his laptop. Well, there is only one pin size for 99.9% of all Sony models made and the part we sent matched the part number it was supposed to be. The customer told me that it was loose fitting and I realized the problem. The DC Jack was cracked. A very common problem in Sony laptops.

When you look at a Sony DC Jack, you should see a bulls-eye, in black or yellow. Here is an example of a surface mount version:Sony DC Jack front view
If you do not see this and instead see two wires sticking out or just a crack down the center, it means that the center ring is cracked and the jack need to be replaced. If it is not replaced and the adapter does not make the proper connection with the jack, you can short the board. If you need to find someone in your area that can replace the jack, we can offer you a local service center. Just email us at info@laptoppartsexpert.com. You can also find the jack for your Sony at http://www.laptoppartsexpert.com/c-43789-vaio.html