No matter how careful you might be, chances are, at one time or another, you will find your computer infected with a virus. If you are a frequent Internet user and you often download videos, music and other files from online, the chances of you picking up a trojan, worm, or other virus are almost assured. Thankfully, there are many great virus protection programs on the market today that can instantly vanquish even the toughest viruses, but that doesn’t mean you shouldn’t have an idea of some of the common computer viruses that are currently going around.
1. Encrypted Viruses – The encrypted virus is probably the most difficult kind of bug to detect and the most difficult to stop. You may accidentally have downloaded one of these bugs and before you know it, your entire computer can be infected. Many top virus protection programs miss encrypted viruses because these bugs use a different form of encryption every time. When the bug wants to run wild, it decrypts itself. In most cases, your virus protection can then identify it and stop it.
2. Secret Viruses – These types of viruses will make changes to files on your computer, or completely replace files, but then try to trick your computer and your anti virus program into thinking that the originals are being used. Most advanced virus protection programs can stop these common computer viruses dead in their tracks.
3. Time Delay Viruses – These types of viruses take a much slower, more disciplined path towards ruining your computer. Instead of instantly trying to take over your computer the moment you download them, they will wait and slowly infect files bit by bit. You may not have been online for days but then suddenly find yourself with an infection. These common computer viruses are the reason why you should run your virus protection every few days, just in case.
4. The Anti-Virus Virus – Believe it or not, there are viruses out there that do nothing more than attack your pre-installed anti virus program in hopes of disabling it so other viruses can then be downloaded. This is why many people have a virus protection program as well as a separate anti-spyware or anti-malware program on their computer.
5. The Multi-Headed Virus – This is one of the most nefarious bugs on the whole Internet. Not only are there parts of this virus that will attach themselves to .exe files on your computer, but it will also affect your computer’s start up so that you begin running the virus every time you turn your computer on automatically.
6. The Misdirection Virus – This type of virus is downright scary. It has a built in subprogram that is made to give false readings to your virus protection software. You think you have a bug in one directory, when, in fact, the virus is busy harming your computer in a whole other area.
7. A Cloning Virus – The cloning virus is an old fashioned type of bug. When you download it, it will quickly create duplicates for .exe files you have on your computer, hoping that you’ll click on it when you really mean to click on a healthy program you already have.
8. The Author Virus – When you download a virus, it usually attaches itself to a program and then runs when you run that program. The Author Virus, on the other hand, finds an .exe file and actually deletes and rewrites code so that the program is changed. Few common computer viruses run this way since the level of virus needs to be so sophisticated.
9. The Bad Penny Virus – The very first computer virus to ever hit the Internet was a Bad Penny virus. This is a bug that automatically passes itself on to everyone on a network or on the Internet unless something stops it. This was the whole reason why firewalls were invented.
10. When most of us think of viruses, we think of PC’s running Windows software. However, there are a handful of bugs out there for the Mac.
11. Rewriting Virus – This bug made a habit out of rewriting some of your most needed files, as well as filling up your hard drive with all sorts of invisible files you couldn’t normally see.
12. The Melissa Virus – This was a bug that hit everyone, both PC users and Mac users. It would automatically email itself to other people without permission. It can be extra harmful if you use a private mail server at your place of employment. The Melissa virus has gone down in history as one of the most common computer viruses of all time.
Showing posts with label Laptoptips. Show all posts
Showing posts with label Laptoptips. Show all posts
Power Connector
Replacing or re-soldering the DC power jack is not an easy job too. It usually takes two to three hours depending on the damage and the model of the laptop. To reach the power jack, the laptop has to be completely disassembled and the motherboard taken out. Then if the board around the dislodged pin is badly burned, the power jack has to be un-soldered and the board has to be patched. After that a different power jack has to be installed, attached to the case of the laptop and connected with wires to the motherboard, as the patched board wouldn’t be strong enough to support the original type of power jack that was soldered directly to the board.On most laptops the DC power jack is soldered directly to the motherboard and there are only three or four small pins holding it in place. Unfortunately that makes the power jack quite weak. Any sideways pulling of the DC power cord while attached to the laptop will usually dislodge at least one of these pins, breaking the solder around it. Modern laptops use quite a lot of power, from about 70W to 120W or even more. The bad electrical connection from the dislodged pin will cause sparks and heating that will eventually burn a hole through the motherboard and can even be a fire hazard. The usual signs of that are:
A common weak spot on most laptops is the DC power jack. If someone trips on the wire while you have the power adaptor plugged into your laptop, chances are that the power jack will get damaged.- The battery is not charging properly or stays at half charge despite that you have been using the power adaptor.
- The screen flickers (the brightness is changing) while the power cord is plugged in. This is caused by the laptop switching between DC power (screen is brighter) and battery power (screen is dimmer).
- The DC plug gets hot after a few minutes of use and may even smell of burning.
- There are “scratching” sounds coming from the DC jack.
There are several models of laptops that are resistant to this problem. All older Dell laptops that use the three pin DC power jack are usually not affected, probably because the power cord pops out easier. Also some older Sony Vaio models, and 1-2 Toshiba models where the DC jack is attached to the case away from the motherboard and all new Apple laptops, where the DC power cord is magnetically attached to prevent any damage to the laptop if someone trips on it.
To test for broken power jack:
- Remove the battery
- Plug in the power cord
- Start the laptop
- Gently wiggle the DC power plug on the back of the laptop
Heat and Dust
The most important part of your laptop that needs to be clean is… the heatsink. Yes, heat is the “cause of death” for most laptops. The heat not only causes all components to expand and contract a little (as you turn it on and off), but will also reach dangerously high levels and make your laptop crash or shut down if the fan(s) and the heatsink(s) are clogged with dust.
All computers work a little bit like vacuum cleaners – sucking air form one side and blowing it out from the other. Unfortunately they don’t come with filter bags to catch all the dust and debris. After just a few months the fans and heatsinks are well coated with dust. If not cleaned, their effectiveness quickly drops and eventually goes down to zero when the heatsinks get fully clogged.
For desktop PCs this process is somehow slower and less noticeable as there is a lot of air circulating inside the case, hopefully with both intake and exhaust fans pushing it through. Also the CPU heatsink and fan are quite bigger and more powerful. There are also fans on the power supply, on the video card and probably on the chipset, for a total count of up to six fans making sure your PC stays cool. However laptops usually have just one or two smaller fans that have to do it all.
I would suggest a little experiment. Look around you for a lamp with an ordinary 100W light bulb. Now turn it on for five minutes and hold your hand about an inch away from it (be careful not to touch the bulb, it will scorch you!). Do you feel it? Yes, that is the heat generated inside that shiny new powerful laptop you just bought.
The cure? It’s easy: get yourself a can of compressed air and blow away the dust off the fan and heatsink. This has to be done every couple of months or after about 50 – 60 days of using your laptop. The compressed air is quite handy for the keyboard too, blowing away all the debris from between the keys. This is not a very well known fact, but it is the most important part of maintaining your laptop.
However if the heatsink has already been clogged, this won’t help. The compressed air will not be enough to unclog it. If you have never cleaned the heatsink and you had used your laptop for over a year, chances are that both the fan and the heatsink are clogged with dust and debris. The solution in this case is to remove the heatsink, clean it and install it back. This is best done in a laptop repair shop, as it takes quite a lot of experience and dexterity. One slip of the screwdriver may kill the laptop!
Some newer laptops have a special removable cover on the back for easy access to the heatsink. But most laptops have to be disassembled to reach it. Another problem is that the thermal paste between the heatsink and the CPU hardens with higher temperature, so if the laptop has been overheating, chances are that the heatsink is stuck solid to the CPU, making it very hard to remove. The process also includes removal of the old thermal paste from both the CPU and the heatsink and applying a small dab of fresh thermal paste, preferably silver filled for better heat transfer.
Another good overheating prevention is to ensure that the rubber feet on the bottom of the laptop are intact. Unfortunately they are usually just glued to the plastic and tend to fall off quite easy. They are very easy to replace and are available as spare parts for most laptops.
And lastly – don’t use your laptop while it’s on a soft surface, like bed cover or sofa. That will block the fan and the laptop will overheat. Try using something with a hard surface under the laptop, like a large hardcover book or a tray.
Simply put, heat is the biggest enemy of all laptops. By maintaining the cooling of your laptop at peak efficiency, you are doubling its lifespan
All computers work a little bit like vacuum cleaners – sucking air form one side and blowing it out from the other. Unfortunately they don’t come with filter bags to catch all the dust and debris. After just a few months the fans and heatsinks are well coated with dust. If not cleaned, their effectiveness quickly drops and eventually goes down to zero when the heatsinks get fully clogged.
For desktop PCs this process is somehow slower and less noticeable as there is a lot of air circulating inside the case, hopefully with both intake and exhaust fans pushing it through. Also the CPU heatsink and fan are quite bigger and more powerful. There are also fans on the power supply, on the video card and probably on the chipset, for a total count of up to six fans making sure your PC stays cool. However laptops usually have just one or two smaller fans that have to do it all.
I would suggest a little experiment. Look around you for a lamp with an ordinary 100W light bulb. Now turn it on for five minutes and hold your hand about an inch away from it (be careful not to touch the bulb, it will scorch you!). Do you feel it? Yes, that is the heat generated inside that shiny new powerful laptop you just bought.
The cure? It’s easy: get yourself a can of compressed air and blow away the dust off the fan and heatsink. This has to be done every couple of months or after about 50 – 60 days of using your laptop. The compressed air is quite handy for the keyboard too, blowing away all the debris from between the keys. This is not a very well known fact, but it is the most important part of maintaining your laptop.
However if the heatsink has already been clogged, this won’t help. The compressed air will not be enough to unclog it. If you have never cleaned the heatsink and you had used your laptop for over a year, chances are that both the fan and the heatsink are clogged with dust and debris. The solution in this case is to remove the heatsink, clean it and install it back. This is best done in a laptop repair shop, as it takes quite a lot of experience and dexterity. One slip of the screwdriver may kill the laptop!Some newer laptops have a special removable cover on the back for easy access to the heatsink. But most laptops have to be disassembled to reach it. Another problem is that the thermal paste between the heatsink and the CPU hardens with higher temperature, so if the laptop has been overheating, chances are that the heatsink is stuck solid to the CPU, making it very hard to remove. The process also includes removal of the old thermal paste from both the CPU and the heatsink and applying a small dab of fresh thermal paste, preferably silver filled for better heat transfer.
Another good overheating prevention is to ensure that the rubber feet on the bottom of the laptop are intact. Unfortunately they are usually just glued to the plastic and tend to fall off quite easy. They are very easy to replace and are available as spare parts for most laptops.
And lastly – don’t use your laptop while it’s on a soft surface, like bed cover or sofa. That will block the fan and the laptop will overheat. Try using something with a hard surface under the laptop, like a large hardcover book or a tray.
Simply put, heat is the biggest enemy of all laptops. By maintaining the cooling of your laptop at peak efficiency, you are doubling its lifespan
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