Tech OverView

Hello world in Java

2013-02-13T11:00:00.001-08:00

Under Construction:

After installing BlueJ a Java SDK you are ready to start.

Open BlueJ.

New life

2013-02-13T10:58:00.001-08:00

As a computer technician I realise the world is changing, and since I've got to update myself as a worker, I decided to develop my knowledge in computer engenering.
Since the normal way to grow this kind of knowledge is to get a degree in computer engenering, I decided to share the way I getting this knowlegde to people o can't have access to this means.

For a starter, I will create a pratical java toturial, explaning the way things are for everyone who doesn't understand any thing about computer programming.

For the first lesson, I advise everyone to start with a basic java compilator like BlueJ.
The reason for using such compilator it's easy. The best way to lear something is to start with the one thing that makes understand the basics of the language, and when using IDE like netbeans or eclipse you lose a lot of habits that will prevent erros in the future.

Allways have in mind that the easy way it's not allways the best way.

So, the second step is to get Java SDK.
Install both BlueJ and SDK and you are ready to go.

Toshiba Tecra R840

2012-04-14T04:09:00.001-07:00

A tech overview on Toshiba Tecra R840.
Better than Satellite line, the tetra product line is designed for the user who looks for quality in the extras that a notebook can have.

The best in R840:

The hard disk is silent and more importantly, is powered to prevent the head read / write to create damage to the disk in case of sudden movements
The matte LCD screen has no glare and, as such, is much less tiring for the eyes
The heatsink and heat pipes are constructed in copper, which is good for cooling the machine. It's own chassis directs the air sucked by the fan into the machine, causing the air to circulate in the area of the chipset
The hinges are solid and well attached to the chassis. Is therefore expected that these do not create problems during the life of the machine
The power connector is not soldered on the mother which prevents problems and allows an easier replacement.

The medium in R840:

The base of the keypad has no holes, but rests on a chassis area with a set of holes through which liquid may enter. Tecra previous segments are better protected in this aspect

Toshiba Satellite L750/755

2012-03-19T17:43:00.001-07:00

A tech overview on Toshiba Satellite L750/755.
Not the top of Toshiba's product line, but it is a notebook that offers excellent price / quality ratio

The best in Satellite L750/755:

The user can easily replace the "CD player", the hard drive, wireless card, and even the battery on the motherboard. However, as usual in the Toshibas, the CPU and the cooler is not easily accessible. To enable the maintenance of these two components is always necessary to disassemble the equipment until we reach the motherboard.
The keyboard has several points of attachment, including screws which ensures that the keyboard is locked and is not floating.
The plate on which the keyboard settles has no slots or holes which reduces the possibility of dirt and liquid passage into the machine.
The motherboard has its top surface laminated, which is also ideal to prevent damage from liquids.
The cables are well secured by gutters which prevents their displacement.
The power connector (also known as DCjack) is connected to a cable to avoid problems of breaking welds.

The medium quality in Satellite L750/755:

The copper heatpipes are generous and well fixed to the bases that remove heat from the CPU and GPU. But it would be preferable, that the radiator by the fan, were also made of copper instead of aluminum
The bases and the hinges are made entirely of metal, but it was preferable that the bases were larger, to better disperse the forces they are subjected.
The memory modules are of different brands and capacities, which, in extreme situations, can harm long-term stability.

The worst in Satellite L750/755:

The chipset has no dedicated heat sink, which may cause overheating problems.

The final verdict (1-5):

Strength ====>3
Quality of manufacture ====>4.5
Maintenance / Upgrade ====>4
Materials ====>4

Although the chassis is built entirely in plastic, Toshiba found solutions to make this series of Satellite solid enough, especially thanks to the many screws and structural attachment points. The weakest point is the screen, since it does not appear to bear big load - cap yields easily creating pressure on the LCD. The care with cables and protection against spills of liquids are higher than is common in a segment of this type.

So in my opinion, for the price it costs and if it has everything you look to in a notebook, you should severely include this model in the list of your choices.

Cisco releases AIRONET 3600

2012-03-19T04:41:00.003-07:00

It is the major release of Cisco this year when it comes to solutions for private clients. It's called Aironet 3600 Series Access Point and has as its slogan a 30% increase in speed of access to Wi-Fi networks. CISCO states that the new access point is a pioneer in the implementation of three "spatial streams", featuring a fourth antenna (4x4: 3). The Aironet 3600 is ready to connect to any device that operates mobile networks. The brand indicates that this access point will be sold with technologies ClenAir and ClientLink 2.0, which improves performance and monitor the spectrum available.

Awesomeness

2012-03-01T20:10:00.000-08:00

No words to describe this:

Recover Dual boot after windows reinstallation

2012-02-27T18:37:00.000-08:00

As everyone knows, when you reinstall Windows you lose boot of Linux, be it Grub or Lilo. This is because Windows writes a new table in the MBR and Microsoft simply ignores the presence of Linux (so it forces the user to give Linux). But today let's ignore Microsoft and recover Linux after installing Windows.

1) start the machine with a live cd either. If you choose a live cd as Kurumin, Ubuntu, Dreamlinux and others, will open a graphical environment that can be Gnome, KDE, XFCE, Ximian among others.

2) press Ctrl + Alt + F2 to go to the shell - as a live cd, it will be as super-user. Basically we do the following: mount your root partition, change the root to this directory and reinstall lilo or grub.

3) create a directory to mount its root:

# Cd / mnt
# Mkdir root

4) mount your root partition, I'll use the default of most machines dual boot here, where: sda1 (sda1) = Windows
hda2 (sda2) = SWAP
hda3 (sda3) = EXT3, ReiserFS, XFS, AMONG OTHERS (ROOT)

Note: We will rely on a ext3 partition, but can be any type of partition for root.

5) we mount root:

# Mount-t ext3 / dev/hda3 / mnt / root

6) we will change the root directory of the live cd to the directory that we set:

# Chroot / mnt / root

Okay, your prompt changes at this time. If you give a cd / always goes to / mnt / root, but appears as /. At this time you're on your Linux. All configuration files are now the Linux on your machine and no longer the livecd.

7) Now let's reconfigure grub and / or lilo. To reconfigure lilo just type:
# lilo

Ready: The lilo will now open the next time you restart!

8) to grub should do the following:

# Grub-install hd0

Where: = hd0 hda
hd1 = hdb

or:

# Grub-install / dev / hda

This variation on the grub command will depend on the version installed on the system, the most accept the two new commands and so on.

Okay, now grub will open at the restart type:

# exit

to return to the root directory of livecd type:

# Umount / mnt / root

to unmount the partition and restart the machine. Get the livecd and voila! Already have the option to choose to boot Windows or Linux.

If your previous installation had only Linux, it will give the option of opening only Linux. Do not despair, the Grub edit / boot / grub / menu.lst:

$ Sudo kate / boot / grub / menu.lst

Change kate by your favorite editor (vi, ... mcedit). If you're using a distro that does not use sudo, do the command as follows:

$ Su-c 'vi / boot / grub / menu.lst "

But graphics editors will not work, so only the text as vi, vim, mcedit. At the end of the file add the following line:
title         Windows 95/98/NT/2000/XP/Vista
root          (hd0,0)
makeactive
chainloader   +1

Where: Title = a label that will appear
root = hd and partition (hd0 = hda, hda1 = 0)
makeactive = mark as active (only for non-Linux partitions)
chainloader +1 = boot rule (always keep +1 for Windows)

Save the file and exit. Okay, just restart.

If you are using lilo, edit / etc / lilo.conf and add at end of file the following lines:
other = /dev/hda1
label = "Windows95/98/NT/2000/XP/Vista(hda1)"

Where: other = partition that should be initiated;
label = name that will appear.

Save the file and exit. Now enter the command:

# lilo

This command will write the MBR lilo again. Remember, other than grub, lilo must be written in the MBR whenever you have changes to lilo.conf. Okay, just restart.

Android development

2012-02-23T16:38:00.002-08:00

A good toturial for developers:

http://www.youtube.com/playlist?list=PL34F010EEF9D45FB8

How to change a mac screen

2012-02-21T17:05:00.002-08:00

This is a complicated thing to do without the correct material.
this is how I do it:

You may do it at home with an hairdryer and some homemade "tools", but be very carefull

BIOS configuration jumper

2012-02-17T14:38:00.001-08:00

The jumper block three-pin BIOS enables all board configurations to be made in the BIOS setup program.

The following text describes the settings of the BIOS jumper block:

Normal (default) (1-2)

BIOS uses current configuration and passwords to run at startup.

Set (2-3)

After the beginning of the POST (Power-On Self-Test) is executed, the BIOS displays the maintenance menu

Recovery (none)

BIOS recovers data in case there is a BIOS update fails.

Quick Start feature
Quick Boot BIOS is a feature that can help reduce the time required for booting Intel ® Desktop Boards.

The quick startup optimization option has three settings that allow general, USB, USB and video optimization is turned on or off separately. By default, all Fast startup options are disabled.

Bios and reinstalling windows

2012-02-16T19:02:00.002-08:00

Some times, your computer is not configured to boot by cd, pen or other device rather then the hard disk.

In BIOS you can configure the booting order. So, if you need to reinstall windows you should acess your BIOS and change the boot order to the device you want to boot from.
So, if you want to install windows on your computer you should change it to boot by cd so the computer can have the instalation program loaded in to memory and then proced the instalation.

In recent computers, there is often a recover function that can be activated in BIOS also. Since it depends on the computers brand you have to look for the option "Disk-to-Disk Recover" or something similar to "Recover option" and change it to "enable". When you restart the computer again you should press the recover button before starting to load windows.

Here is a list of some "recover key" often used by brands:

ASUS - F9
TOSHIBA - F8
ACER - ALT + F10 or F10
HP - F11
PACKARD BELL - ALT + F10 or F10
SONY VAIO - F9
INSYS - F8
FUJITSU SIEMENS - F10
COMPAQ - F11
this is the most often used key, but it can change in some models

Here is a list of boot menu shorcut key (used to change the boot device just for that particular boot):
ASUS - ESQ
TOSHIBA - F12
ACER - F12
HP - F9
PACKARD BELL - F12
SONY VAIO - F12
INSYS - F12
FUJITSU SIEMENS - F12
COMPAQ - F9
this is the most often used key, but it can change in some models
this option may not be activated in BIOS. To activate it, look for "%the key% Boot mode" option.

Loading Default Values - Bios

2012-02-16T03:11:00.003-08:00

One thing that can solve some problems is to do a BIOS reset.
Given that the BIOS does control all the components (as described in this previous post), if it happens a hardware conflict or a BIOS misconfiguration can cause all sorts of trouble.

There are two ways to do this process:
1 - Accessing BIOS and doing "load default values."
2 - Removing BIOS battery

1-

Press the HOME button

Press the F5 button

The first is quite easy to make and difficult to describe because the BIOS changes from computer to computer.
Here are two pictures of two different BIOS settings but the same brand.
At the bottom of the screen should appear an option that says "setup defaults", "load default values", "set default values" or something similar. Choose this option by pressing the indicated button.

After this, repeat the same operation for the option "save and exit", "Save changes and Exit" or some thing similar.

2 - The second form is quite complicated if we are talking about notebooks / netbooks.

DESKTOP CMOS/BIOS BATTERY


LAPTOP CMOS/BIOS BATTERY

LAPTOP CMOS/BIOS BATTERY

You have to open the computer and look for the BIOS battery, and remove it. Then, with the computer unplugged press the on/off button for 20 seconds. Place the battery again and restart the computer.

If not solved the problem, look for other posts with the specific description of your problem to have more detail.

Bios

2012-02-12T16:40:00.000-08:00

Bios is the Basic Input / Output System. The BIOS is a software construction that determines what a computer can do without accessing programs from a disk. In PCs, the BIOS contains the code required to control keyboard, display screen, disk drivers, communication and large number of other functions.The BIOS is usually stored in a ROM chip (Read Only Memory) that comes with your computer. This ensures that the BIOS will always be available and will not suffer damage with disk failures. Current models of PCs are equipped with BIOS stored in flash memory (nonvolatile memory that can be erased and rewritten) that can be updated if necessary.

Updating Bios Can be very important in some cases since it can solve a few hardware conflits.
Be aware that a BIOS update is a very dangerous thing to do if it's not done correctly.
In the next days i'll start explaning what is important in BIOS for you to know when repairing your computer.

Memory vs Diagnosting hardware problems

2012-02-09T14:21:00.000-08:00

By the fact that many computer problems manifest themselves as memory problems, makes the diagnosis of the real problem rather difficult. For example, one problem with the motherboard or with a specific software can generate a memory error message.

Since

Common memory problems:

When you have a problem in memory, it is caused usually by one of three causes:

Improper Setup: The memory model is not correct for your system or not followed the rules for setting the correct way.

Improper Installation: It may not have fitted well into the slot, the slot may be damaged or the groove may have to be clean.

Defective Hardware: The memory module may be a manufacturing defect.

So, in order to have a good hardware diagnost it's important to first rule out memory problems assuming that they can be any of the described above.

So, first you should check if the memories supported by the motherboard, and althought the slot fit differs between type of memory, it still may occur compatability problems. Some motherboards (for exemple the early version of Acer Aspire One boards) don't support more than 1gb or don't support more than 553 Mhz. In that case the upgrade of memory can not excede the 1gb by slot.
So garantie that the second problems doesn't occurs you should simply clean the memory with the correct products.

I normally use this spray and a

rubber to clean every electric

component on any computer

(including the slot, and the memory):

To be shore that the problem is not related to a defective memory you to try a new one.
If the problem persists, it's problably related to another component or Motherboard (that can include the board slots).

Rebaling vs Rework

2012-02-07T12:33:00.000-08:00

The rework of a graphic card on a notebook can solve the problem of a blank screen on most of times, but it's only a temporary solution to the problem. Most of the times, the gpu reheats and even with newer heat more efecientes solutions you will have the same problem in a matter of months.

So, even thought it's more expensive to do a reballing, it can be a better way to ensure that the repairment will have a long-term effect.

Here is a video that can clarify what is the reballing concept.

This is an advanced technique, so it is not advisable to try it without the correct materials / machines.

Thermical Mass

2012-02-07T10:03:00.000-08:00

introduction

For most beginners, this is without doubt a subject to be explored and so is this article even here, taking also into account that the newbies often ask what good thermal mass, or when it is applied and why.

Which one to choose?

There are currently various brands of thermal mass starting with the most well known of the Arctic Silver which has different types of thermal mass each with a slightly different composition, to Cooler as marks, OCZ among others. The choice of the thermal mass should be made as appropriate. If for example you want to use thermal paste in memory or in some chip that has no mounting holes, must choose between one of the folders and thermal adhesive preferably opt for a non-conductive paste, lest any chance of placing. If you want thermal mass to the CPU, you can either opt for conductive and non conductive mass, but agree to have some aspects in mind such as the fact that AMD void the warranty on your cpu used when a conductive thermal mass. If you want a thermal mass for the gpu of your graphics then use a mass preferably non-conductive but good quality.

Avoid at all costs to use that white thermal mass, which usually comes with the fans, given that mass is of poor quality. Overclocking In more worth spending some money on a good thermal mass that want to save at all costs, due to the need to dissipate existing.

What is?

Any metal surface is uneven to a certain scale that does not need to know and one of the objectives of the thermal mass is to eliminate the most of these micro irregularities. The other cause is of course there is greater contact between the base surface of the cooler and the CPU, which is only achieved by using a thin layer of a thermally conductive component, in this specific case we speak of thermal mass.

When should it be used?

When mounting a heatsink, this cooler is for memories, for the Northbridge, Chips, CPU, GPU and the like. When not using thermal mass, more specifically the GPU and CPU is running a relatively high risk of burning your component in question and all is not what we want. If you care to choose a good thermal mass can earn about 5 ° temperature at full load compared to the thermal masses of inferior quality.

The thermal mass to have an overall performance must be applied in very thin bed, recommended by manufacturers of thermal mass is anything to 1 mm (roughly the thickness of a sheet of paper). The fact that weight loading in excess will cause the cooler pressure exerted to move the mass and do create irregularities in its application. This is valid for any component or CPU, the only difference to be applied for example in a thermal P4 or an AMD is the fact that in the P4 core Tues Hetspreader which facilitates the application of mass, while the lack heatspreader amd so that the pulp has to be applied directly to the CPU core.

Note: Allways clean the cooler and the CPU before aplying

Aplying the thermal mass:

The thermal mass to have an overall performance must be applied to a bed rather The best way to apply the thermal mass is pour some of the same one end of the core or heatspreader and then spreads it with a blade, but when they have more experience can pour the batter in the center which will have no difficulty in spreading it. To know if you apply the right amount of mass must (when you have mass spread around the cpu) for making a little more pressure to feel the blade touching the cpu obviously should not push for that to happen constantly , but must pass the blade slightly so that it is only a thin layer.

To spread the batter can for example use an x-acto blade of a departure to some extent, will spread as in the previous image, if they have mass in excess will apply the cleaning blade to remove the excess.

In the case of the mass to be conductive and even not being one must be careful when making the application so as not to put weight in non-payable. Before making the application must clear the cpu core or Heatspeader with acetone to remove the mass before or other impurities. A finger mark or a bit of dust in the place where they will be applied to mass can affect the final result.

It should also clean the bottom of the cooler, even with acetone or sanding water and acetone, and applying a small amount of mass.

Then clean up the base of the cooler with a cloth that leaves no unwanted particles in a straight circular

The purpose of this step is to improve the surface of the cooler, because as everyone knows the surface of whatever is seen in the microscope is imperfect and this method is the thermal mass housing on the micro-cooler failures making the surface more perfect and consequently perform better with the CPU.

Black Screen problem

2012-02-06T17:19:00.000-08:00

The first thing to do is to eliminate any static electricity on the computer, doing as shown in the video above.

Note: the problem is not solved as it is explained in the video, but it helps prevent other problems during the repairment.

After the first step you are ready to start the repairment and you only need to follow the next video indications.

Wifi best channel solution

2012-02-06T09:17:00.000-08:00

In order to get a wifi network with better performence, it is necessary to take into account several parameters, such as the antenna, wifi mode, the conditions of the site, building materials, and also the channel where the wifi network is to be issued.

Today we will talk about how it is possible to improve by simply changing the channel to be issued:

First step:

Meet the networks that are in the field of action that we intend to improve.
To do this, we run a program that will indicate which channels are used by the networks with more power signal in range.

inssider

Second step:
Install the program, and run it.

Thrid step:
Observe the channels that all networks send and check which one (between 1 and 13) is free or with less used by other networks.

Fourth step:

Access your wifi router and look for the wireless configurations.
Change the channel to the least used