Published by admin, on Dec 04 2010, in the categories: General info
The 10BASE-T (10MB per second) baseband is an implementation of Ethernet which allows stations to connect via twisted pair cable. The 10BASE-T uses UTP cable to connect computers. Both 3.4 and 5 UTP twisted cable is used to actuate the network. The 10BASE-T networks are in general configured in a star pattern. However, its logical topology is that of a bus.
The 10BASE-T name refers to several aspects of the physical medium. The number 10 comes from the 10MB per second transmission speed. The BASE stands for baseband. Therefore, only one Ethernet signal is present on the send or/and receive pair. Furthermore, the multiplexing process lacks form broadband transmissions. The T stands for twisted pair, which identifies the type of cable used in this transmission.
The nominal segment length for a 10BASE-T cable is 100 meters, a substantial improvement from 10 meters found on 1000BASE-T and 100BASE-T. The minimum cable length between computers is eight feet. The maximum number of nodes that can exist on the 10BASE-T network is 1024.
Although previous Ethernet standards, such as 10BASE2 and 10BASE5, specify the exact type of wiring to be used, the 10BASE-T standard lacks this specification. However, this was done in anticipation of using 10BASE-T in existing twisted pair wiring systems that could not conform to any specific wiring standard. Further on, the 10BASE-T wiring includes a specific set of characteristics. Every 10BASE-T link segment must conform to the following set of characteristics that includes specifications, such as timing jitter, attenuation, propagation delay, characteristic impedance, and several distinctive types of noises. These characteristics are expected to be met by 100 meters of 24 gauge unshielded twisted pair cable.
Similar to several other standards, the 10BASE-T standard uses the RJ-45 jacks. The RJ-45 jacks are either wired to the TIA-568B standard or wired to the TIA-568A standard. In the wiring process only the second and third pairs are used, represented in colors by green and orange. The TIA-568A standard directs pair two – orange on pins 3 and 6, pair three – green on pins 1 and 2. The TIA-568B standard puts pair two – orange on pins 1 and 2, pair three – green on pins 1 and 2.
The hub of the 10BASE-T networks acts as a multiport repeater. Each computer is connected to the end point of a cable that is connected to the hub. This can be done by transmitting on pins 1 and 2, and receiving on pins 3 and 6, while a 10BASE-T node transmits on pins 3 and 6 and receives on pins 1 and 2. If the wiring standard is identical on both ends the segment is a patch cable suitable for transmission between a switch, a hub and a patch panel and a node. However, when the wiring standards are reversed on either end of the segment there is a crossover cable suitable for connecting a node to a node or a switch/hub to another switch/hub. The 10BASE-T standard is at its core a StarLAN-10 with the addition of the link-beat.
Located in the OSI model, the 10BASE-T is found at the physical layer. In the OSI model, the 10BASE-T is one of the several physical layer standards for Ethernet. Other standard for Ethernet are 10BASE5, 100BASE-TX, and 10BASE2. Ethernet encompasses both addressing at the data link layer and a number of physical layer implementations. The Internet Protocol (which is a network layer protocol) doesn’t usually know whether it is hosted on 10BASE-T or not, even if it known it is being hosted over Ethernet.
- Maximum segment length of 100 Meters;
- Hub to Hub or repeater to repeater links limited to 100 Meters.
- Star topology;
- 4 repeater/5 segment rule of 10Base5 is retained;
- Only two nodes per segment are allowed.
- RJ-45 Connectors;
- Category 3 UTP minimum, preferably Category 5.
Difficult for a first PC to reach the level of finishing of a model two times more expensive. The plastics used are clearly low-end, especially the buttons above the keyboard and below the touchpad. Good point regarding the screens enclosures and chassis, since the coatings are dull and do not take fingerprints. Instead, the cover of the screen is completely brilliant and gets dirty very quickly. The whole gives an impression of strength, especially as the hinges of the screen appear strong.
The keyboard could not be more classic. It has the merit of integrating a number pad, a rarity on the 15.6-inch models. Unfortunately, the Fn key is in place of the “Ctrl”, which is problematic to use. This could still be satisfactory if the adjustments were good. Alas, the top of the keyboard is not secured properly, it moves and causes unpleasant clatter. Maybe it is just an error during assembly on this specific item. That said, our copy is a new model, which still leaves suggests a defect in the product verification at the factory.
The multi-touch touchpad is good size. Its matte surface provides a comfortable glide and accuracy is the rendezvous. Clicks located below are assembled, if not aesthetic. Asus UL80V webcamlive webcam is just correct. The burned areas are overexposed and she needs a high enough brightness to function properly. The fluidity is good. The microphone is unfortunately positioned right of the keyboard, which causes noise during operation if one writes the keyboard. The breakdown of the machine is relatively quiet for the category. Although the fan emits a continuous regular breathing. The noise is amplified during intensive treatments (photo editing, video encoding, etc..).
The connection is complete despite the position of entry level machine. The DVD burner is located on the left edge, next to the breakdown. Right side, there is a USB port, a memory card reader 10 in 1, and the headphone and microphone. Finally, at the rear of the machine are three USB 2.0 ports, 1 VGA and 1 HDMI, 1 RJ45 (Gigabit Ethernet) and an RJ11, the electrical outlet and lock. Wi-Fi N is also present. On the device, 3 hatches give access to all components of the machine, which is very convenient.
Calculations: dual-core assures a minimum of comfort
Index Windows 7: 4.9. Details: Processor 4.9 – 5.4 RAM – 4.9 Graphics – Graphics Gaming 5.9 – 5.6 Primary Hard Disk.
The Intel Celeron Dual Core T1400 that this team ASRock M15 is an entry-level model. However, its two cores allow it to ensure comfort of use, despite a low overall index of 34.11
Summary of program and problem concerned
* This program is designed to offer assistance to customers who own laptops may be affected by a problem related to components of a third party supplier of Toshiba, defined below.
* This program will allow users to eliminate the problem by replacing the memory module (“component of origin”) delivered to Toshiba by third-party vendor. No other component is replaced.
* This problem affects only certain laptops, whose models are listed below. No other product or hardware is involved.
* The laptops currently manufactured by Toshiba are not affected.
In certain circumstances, the original component, provided to Toshiba by third-party and installed on specific models produced a defining moment, and used in combination with certain other components, may lead to the presence Notebook Screen blue, intermittent crashes, or corruption undetected memory data. However, the risk of encountering these problems is extremely small.
As part of its commitment to customer satisfaction, Toshiba launched, from 1 November 2004, a voluntary program of sharing components worldwide, for customers with laptops include the original component implicated. List of models of laptops equipped with the original component involved.
If your laptop model is listed, Toshiba has developed a utility that will help you determine if your computer can be affected by the problem described above.
Description of the exchange program for laptops equipped with the original component involved
Under the exchange program:
All customers who own Toshiba laptops that could be affected by the problem described above, have the opportunity to receive a free replacement memory module (“component replacement”). They can install it themselves, or they will be asked, according to the ease of installation and / or geographic area, to return their laptop to Toshiba or Authorized Service Centers listed for free installation component replacement.
What if the utility indicates that your laptop has an original component covered by this exchange program.
Toshiba has developed a utility that will help you determine if your laptop has an original component can be affected by the problem described above, and if your computer is covered by this program. In this case, you will be asked to follow the instructions displayed by the utility to order a replacement component to Toshiba, free.
If the utility tells you that you must return your notebook to Toshiba or an authorized service center, follow the instructions displayed by the utility that will explain how to return your computer. The shipping the laptop, the replacement component and its installation will not be charged.
We are launching this program voluntary exchange as a preventive measure in the context of our commitment to customer satisfaction. We are concerned for the smooth running of your business and we sincerely apologize for any inconvenience this may cause.
Contact Toshiba: For questions, please contact your local Toshiba representative or authorized service center.11
In order to spend you’re money wisely and choose the best Toshiba laptop battery for you,here is some info on this subject. Choosing the brands of batteries, especially not to buy the cheap batteries imported directly from China, they can be extremely dangerous because they will suffer very little control of manufacture, or none! So beware, they can be very dangerous!
Do not exceed the discharge current specified by the manufacturer of the battery (eg if marked 4400mAh so it will not pull more than 4.4 A for one hour) for fear of damaging it considerably. Clearly, it is recommended to use your battery to power other machines.
A very important announcement above: never fall below 10% load. In general the OS whatsoever, directly puts the computer to sleep when it is more than 15% of remaining charge.You can really lose 20% capacity in one fell swoop, I personally lost 10% capacity of a sudden wanting to try …
* Allow the battery to charge quietly without using it. Rest assured, when you recharge your battery power cord divides his power part is then to charge your battery, the other is used for the operation of your laptop, so your battery is not used for this time.
Calibration: this operation is to “reframe” the full charge your battery. To do this, when the battery is discharged at the maximum (not below 10% but when the OS puts the laptop in standby) it needs recharging completely without interruption. It actually allows your battery to undergo a full discharge followed by a full charge, which maintains it. It is advisable to do this manipulation 1 to 2 times per month.
Another important point also is that it is unnecessary to remove the battery from the computer when not in use and the PC is connected to the mains, simply because all current laptops or the batteries themselves are equipped with electronic circuits that avoid using the battery when it is charged and the laptop is connected to the mains. By cons are advised to unplug the power cord to a laptop when it is turned off to avoid any unnecessary burden micro-battery.
It seems that Sony flange charging batteries of their new laptops to 80% for the wear limit, so do not worry. It is normal if you can see on a Sony laptop.
Do not forget: a battery does not throw in the trash but recycled and wears even when not in use.11
In this article we are going to go though the basics of Dell laptop monitor replacement. Since everyone is looking in our days to so the laptop repairs themselves at home, we though such an explanation would be useful for some of our readers. When it comes to Dell laptop monitor replacement, it’s difficult to explain the process for every laptop model so we have decided to focus on a specific model. Most laptop manuals explain how to take apart a laptop. It’s sometimes better to consult the manual that came with your laptop or the ones which are available online from Dell as they are particularized for all the laptop models available on the market in this moment. We are going to go though the steps of removing the screen on a Dell Latitude laptop.
The first step when taking apart any electronic gadget is to make sure there is no electricity running though the gizmo because nobody wants to have unfortunate accidents at home. Take out the laptop’s battery and the power adapter from the unit before doing anything else. Look closely at the screen’s bezel and you will notice screws which are normally located on all the four corners of the display. Very often, these screws are hidden by rubber covers and you need to remove them with a sharp needle in order to gain access to the screws.
To remove the screws, you are going to need a Philips head screwdriver. These screws secure the plastic bezel and after they have been removed, the bezel has to be unsnapped from the rest of the lid with great caution because applying force can cause cracks or damages in the bezel. You could start from the right corner and then gently remove the bezel by going to the middle and then to the left side of the screen. There are latches made out of plastic that need to be unlocked. When the tabs are hidden, you could try and find them with a screwdriver. Just use the screwdriver between the bezel and the rest of the lid and move it around in there until you find the obstacle. Then you can press the bezel at that point and the latches should release.
After you remove the bezel, the screen will still be attached to the rest of the lid as there are some more steps which you must follow. There are four screws which need to be removed in this next step. After you’ve done that, carefully place the screen on the keyboard (put a towel between the two if you don’t want the LCD to get scratched) as there are still cables connecting the display to the back of the lid. There is a video cable which looks like a ribbon. It is used for delivering digital video signals to the display.
There is a push together connector which can be removed with a simple grasp right at the connector. Then you can pull it out carefully. Now you have to take care of the inverter connector. The inverted circuit is used to power the backlight of this Dell. The CCFL (which stands for Cold Cathode Fluorescent Lamp) requires high voltage in order to strike plasma. This kind of tube has a better life expectancy than the usual inverter and this is why most techs are going to replace the inverter before messing around and removing the backlight.
The next step will require removing that grey metal structure which keeps securing the display to the back light assembly. There are a dozen metal tabs which are bent into the depressions of that white plastic holder. They can easily be removed with the help of a small screwdriver. Dell has taped together the units on the top and bottom. This LCD uses a translucent light panel which comes in addition to the backlight. The light panel helps spread the back light evenly so there won’t be any differences of light between different parts of the screen.
The CCFL backlight is secured in a special channel with the help of a strip of copper tape. You can use the tape again or you can replace it. When you expose the CCFL you can then pull back those rubber insulators located on the ends and unsolder it. This CCFL tube is soldered to the inverter on both ends. Removing this back light is only necessary if this is the actual problem with the LCD, it does not have to be removed if you simply want to replace the screen with a new one.
When you have removed the ribbon tape, then you can remove the LCD and ignore the other steps presented afterwards. If you want to replace the monitor and put a new one in your Dell Latitude laptop, you have to reverse the process and put the display assembly back together. Connect the video cable again and hold the LCD back in its place until you put back all the screws to put the grey metal structure back in its place.
After that, put the screen bezel back but snapping it back into those latches which you had to locate with the help of the screwdriver. When the bezel is back in its place, you have o put the 4 screws back together. Make sure you hide them again using the rubber covers which you removed in the first place. It should be easier to put the rubber covers together as you noticed that Dell did a pretty good job in putting them in there. They were really difficult to remove. Then put the battery back in the laptop or connect the power adapter and turn on the laptop to check if the new display works.
As you can see, the process is pretty simple and you don’t need any exceptional tech knowledge to remove and replace the screen by yourself. If your laptop is still in the warranty period, we recommend you take it to a special computer service as you may void the warranty if you mess around inside the laptop.11