Category Archives: laptop accessories

How to Choose a Laptop Screen for Replacement

Posted by on July 26, 2012 No comments

We used to agonize about different grades of LCD screens, but you can assume that Active Matrix laptop screen is a better version of LCD compared to Passive Matrix. LCD screens are perfectly flat, about half an inch thick, and use less power than old CRT screens. The reason for the main power drag on the LCD is the delay to run a backlight firstly then to illuminate the display. On top of that, the backlight has to shine through the screen and illuminate even when you are viewing a dark screen. Until there’s an alternative such as a self-illuminating screen, we are stuck with lighting up a backlight. That’s the way it is.

Laptop Size
Clearly, a laptop with a 15.4″ diagonal screen is going to be physically larger than one with a 14″ or 12″ or screen. The actual size of the laptop has been increased in order to hold the larger screen. So, choose wisely if you want a big screen–you may not be happy with a laptop that is poorly portable. If you want a giant desktop replacement laptop, you can get a screen as big as you like. But it’s still worth a second thought. As we find two hands are needed for an average man carrying a 15″screen to a different room, not mention the larger-sized ones. If you want a “normal”-sized laptop, we highly recommend the 13″ or 14″ screen. It would be a decent compromise between size and heft.

Widescreen vs. Standard Aspect Ratio
Although you can still find them here and there, standard aspect screens (4×3 aspect ratio) are starting to disappear. That’s kind of a rip-off, as regular aspect ratio screens are bigger than wide screens, with 16×9 ratios. Now that there’s a widescreen craze with big TVs, the little screens are following, and we will probably be in an all-widescreen world pretty soon; so, we won’t worry about it too much. The LCD makers have geared their factories towards the wide screens, and that means cheaper wide screens.

Screen resolution
Resolution refers to the amount of pixels across by the amount of pixels up and down. Usually, bigger screens mean bigger resolutions. Also, cheaper screens of the same size have less resolution. You may want to upgrade to the “+” version of the screen you are thinking about if you have good near vision. It will give you more room to move things around and you can see more stuff at once. If you want to see big text, you may want to consider sticking with the standard screen, or even looking for a cheaper model with a lower resolution. We are getting closer to a time where font size and screen resolution won’t matter, but we aren’t there yet. You may want to go and look at different screens at a local computer or electronics store to figure out what size and resolution you like. As time goes on, larger screens keep getting cheaper, and instead of increasing screen size too much, laptop prices have come down. If you are aiming for a very small notebook, you will most probably end up with a 12″ screen.

Here’s a range of laptop screen sizes and the resolutions that are often displayed on the screen. To give you an idea of how much you can see on the screen we include megapixel values for each screen size:

 

Screen Resolutions (in pixels)

Possible LCD Sizes (diagonal)

Viewable Megapixels

800×600 (SVGA – standard)

12″

0.48

1024×768 (XGA – standard)

12″, 13.3″, 14″, 15″

0.79

1280×800 (WXGA – wide)

15.4″, 14.1″, 13.3, 12.1″

1.02

1440×900 (WXGA+ – wide)

14″

1.30

1280×1024 (SXGA – standard)

14″, 15″, 15.7″

1.31

1400×1050 (SXGA+ – standard)

12.1″, 14″, 15″

1.47

1680×1050 (WSXGA+ – wide)

15.4″

1.76

1600×1200 (UXGA – standard)

14″, 15″, 16″

1.92

1920×1200 (WUXGA – wide)

17″, 15.4″

2.30

 

Ewoomall now has an abundant supply of laptop screens. In order to choose a compatible screen, besides several basic rules mentioned above, you may also need to know the model number of your screen. You can check it immediately on the stickers on your screen.

Blow is a list of LCD screen manufacturers with their abbreviations:
Acer – L
AU Optronics – B
Chi Me – N
Chunghwa – CLAA
HannStar – HSD
Hitachi – TX
IBM ( IDTech) – IT or IA
LG Philips – LP
LG Display – LP
Matsushita – ED
Mitsubishi – AA
NEC – NL
Quanta – QD
Samsung – LT or LTN
Sharp – LQ or LM
Sanyo / Torisan – TM or LMJK
Toshiba – LTM or LTD
Unipac – UB

We are here providing more than 2000 kinds of laptop screens, including Samsung, LG, Dell, HP, ASUS, etc. You can choose yours from here. We have monthly Specials, which you can check from time to time if you have a tight budget. If you still have problem finding the right replacement LCD screen, please contact our customer service with following information like the laptop model, P/N, former screen model, etc. Email: support@ewoomall.com

The Most Common Laptop Battery Problems

Posted by on September 2, 2011 No comments

Laptop batteries can often be expensive because the laptop manufacturer is the only one who makes a battery to fit their particular laptop. This is done so the manufacturer will have control of the market when you need a new battery. Often this is done to encourage you to buy a new laptop instead of replacing the battery. In many cases there is little difference in the price, which is what the manufacturer intended.

Some laptop batteries, such as the Ni-Cad, will suffer from a problem which is commonly called the memory effect. This is caused when you continually recharge the battery without letting it discharge entirely. After a time the battery will forget that it has unused capacity and it will discharge much faster each time it is used. The best way to avoid this laptops batteries problem is to allow your battery to completely discharge at least once each month. This allows the battery to retain its original memory and provides longer usage.

When your laptop is not in use for an extended period of time it is best to remove the battery. The battery will continue to slowly discharge during the time it is not in use. If this discharge takes place inside the laptop you may not be able to get your laptop to recognize the battery the next time it is recharged.

You can also experience battery problems if you allow your battery to completely discharge outside the laptop. You should check the battery while it in storage so it will not be allowed to completely discharge. This could also prevent the laptop from accepting the battery when you place it back into the computer.

If your laptop batteries become hot to the touch you will need to remove the battery and allow it to cool off. If this problem continues when you replace the battery in the laptop, you will probably have a defective battery. It is best to remove the battery and replace it since a defective battery could cause extensive damage to the laptop.

Temperatures have an effect on laptops batteries. If you are experiencing extremely hot temperatures you will need to keep the battery in as cool an area as possible. Extreme heat can cause the battery to discharge prematurely and can eventually lead to battery damage.

Last year Toshiba recalled about 430,000 laptop batteries because they continued to lose power prematurely. Toshiba also reports that although these batteries were giving problems by losing power, there were no reports of the batteries overheating and there were no reported injuries as a result of the defective batteries.

Before the Toshiba recall, Dell and Apple had a battery recall because Sony had produced a defective batch of batteries. These batteries were known to overheat and some of them even produced fires. All of these batteries were replaced free of charge but the company did suffer some financial damage as a result of the recall.

Panasonic also had a laptop battery recall because the latches were defective. This was causing a mechanical problem with the batteries because they were not properly latched in. In many cases these batteries overheated but there were not reported injuries.

How to Choose An AC/DC Adapter?

Posted by on August 30, 2011 No comments

With an increasing number of new electronic gadgets – phones, music players, PDAs, handheld games and other toys – comes an increasing number of AC Adapters needed to charge and power those gadgets. Often the adapteris lost or broken, and choosing a replacement can be confusing because of the variety of selections available

1.    Determine the desired output specifications of the AC adapter.

This can usually be found on the old adapter, the electronic device, or the instruction manual of the electronic device. There are two components to this: the voltage, measured in volts, and the current, usually measured in milliamps (ma). When selecting an adapter, you will want to match these as closely as possible.

If an exact match is not available, it is better to err on the side of the new adapter having a lower voltage and higher current than the specifications require. For example, if the device calls for 6 volts at 500 ma, it is preferable for the new adapter to provide 5 volts at 600 ma (lower voltage, higher current) than it would be for the new adapter to provide 9 volts at 333 ma (higher voltage, lower current), as the excess voltage could damage the electronic device.

2.   Determine whether the adapter should be regulated or unregulated.

Simply put, an unregulated adapter does not always produce the rated voltage while a regulated adapter does. Because of this, regulated AC adapters are also generally more expensive than unregulated ones.

It is possible to substitute a regulated adapter for an unregulated one (the downside being added cost), but it is not advisable to substitute an unregulated adapter in place of a regulated adapter as this could cause the electronic device being powered to fail.

3. Determine the polarity of the adapter, which will either be positive or negative.

The following image shows how polarity is usually represented.

Polarity determines the direction that current flows; if the current from the adapter flows the wrong way for the intended electronic device, the device may be damaged. It is important to be sure that the polarity of the adapter and the device match.

4.  Determine the size of the adapter plug.

Plug sizes are normally measured in millimeters. If the plug size is the only thing wrong with an adapter, meaning that its voltage and current ratings, whether it is regulated or unregulated, and its polarity all match, it is possible to splice a new plug onto the adapter, as many electronics stores do sell just the plug in different sizes. However, care must be taken to ensure that the new plug maintains the same polarity as the old one, meaning that the wire that connected to the outside surface of the old plug still connects to the outside of the new plug, and that the wire that connected to the inside surface of the old plug still connects to the inside surface of the new plug

5. When finding your laptop ac adapter on ewoomall.com, you can simply put the model no or P/N in the tab on the left top and search. We name adapters by model or P/N in the title.

If you still have problem finding the right one, please provide as much information as possible, including the laptop model, P/N, output specifications on the old adapter, etc, and contact our customer service. Email: support@ewoomall.com