Analyzing and Understanding the Motherboard:
Understanding, a laptop motherboard is divided by some sectors that we identified by switching sources, we will see in this forum each one of them, how to know which source is defective and which component needs to be replaced for the board to reconnect.When analyzing a defective laptop on the motherboard you should not blindly measure component by component. This would take time to repair and you would probably get lost.
The most efficient strategy for a quick analysis and diagnosis is to measure the voltage outputs (through the inductors) of the switched sources on the motherboard with the aid of the electrical schematic (Example: 3V, 5V, etc.).
Assuming that one of the motherboard sources is missing its voltage, then it will be necessary to analyze only the circuit of that source, thus speeding up the repair.
At that time, the analysis of the terminals of the source PWM IC starts to know if it is working. If it is ok, then we start with the other components that make up that source.
Maybe you are a little confused now, but don't worry, we will analyze each one of these items in more depth later on.
Finding a defect is a process that is quick most of the time, but it can sometimes take a little patience too.
Schematic Diagram:
If you could have a map that will guide you to find any defect in a laptop in minutes, would it be good?Yes, this map exists and we call it the Schematic Diagram (Electrical Scheme), and through the use of it this becomes possible.
This is perhaps one of the most important parts I wrote in this e-book, because his subject is one of the main divisors of water for those who want to work with laptop maintenance.
So pay special attention to it, until you assimilate all the content well.
Well, after all, what is a Schematic Diagram?
Electrical schematic or electrical diagram or schematic diagram is nothing more than the graphical representation of all circuits on the laptop's motherboard.
In a very practical way it is a PDP file that contains information about the operation of a particular laptop.
It is through the analysis of the electrical schematic that the technician can quickly reach the solution of a defect.
Without it, it becomes very difficult and time-consuming in most cases.
Here are some benefits of working with the wiring diagram:
1. Circuits are separated by pages, facilitating analysis through measurements at strategic points.
2. The main components used on the motherboard of the schematic in question are listed on a single page (block diagram) (Super IO, North Bridge, BIOS IC, PWM ICs, etc.).
3. Page with the summarized sequence of operation of the laptop (step by step, voltage by voltage that must appear on the motherboard for it to work).
How to get the Schematic Diagram?
When repair a laptop motherboard, this basic laptop motherboard information you must know and what’s their purpose to use it.
General Information about laptop motherboard:
Brand and Model Number:
Identifying the correct laptop brand, series, model number, screen size and resolution is essential to finding the correct part for your laptop. The laptop series is typically more prominently displayed as part of the branding of your laptop, typically on the top cover, or on the keyboard area or display panel area of your laptop when you open it up.
OEM Laptop motherboard:
OEM or original equipment manufacturer, all branded laptop computer like Apple, Acer, Dell, HP, Lenovo and etc, they are not manufacture their laptop motherboard. All of them are using the third party company design laptop motherboard to build their own brand laptop.
The popular OEM Company is Compal, QUANTA, Wistron, Inventec and Pegatron.
These OEM Company have a huge market percentage on production of laptop motherboard.
The second line OEM manufacturer like: MITAC, Clevo, FIC, MSI, ECS, Flextronics, Foxconn, Topstar and etc.
List of some OEM (Original Equipment Manufacturers)
Quanta are probably the biggest laptop manufacturer, followed by Compal and Pegatron. Compal and Pegatron probably have the best quality overall. Information about the manufacturer and motherboard model laptop very important to us, you might need to know model number motherboard’s model for a number of reasons as stated below:
- Looking for motherboard BIOS file or the need to update the BIOS of motherboard.
- Looking for a motherboard schematic.
- Need to update the drivers of hardware as audio drivers.
How to get the schematic diagram?
The easiest way to look for the schematic diagram in the internet is by using the laptop reference, for example: Acer Aspire 1300, Hp pavilion DV5-1000us etc. In case you don't find the schematic using the laptop reference you can use the ODM. To look for the motherboard schematic using the ODM method look for a reference printed in the motherboard and use it to search for the schematic, below is an example of those references for ODMsFind the Motherboard ODMs (Original Equipment Manufacturer)
This is usually printed on the motherboard, but can be located in several possible locations, for example, it may be printed near the RAM slots, near the CPU socket, or between the PCI slots. There will be a lot of writing on the motherboard, but the model number is usually written in the largest text (Motherboard model numbers are typically a collection of numbers and letters).Look for your motherboard schematic online:
Go to a search engine of your choice (Google) then type in your model number (ODM) followed by the word "Schematic or Diagram" and press entre, this will bring up a list of matching schematic motherboard models.Carefully review the search results. Watch in particular for results in PDF format, as most manufacturers that do list their schematics online will do so in PDF (Adobe Acrobat) format.
We need to understand what it is and how the components of a laptop (capacitor, resistor, diode, etc.) work before starting to
analyze and interpret a schematic. The electrical schematics may seem complex at first, however, in a short time, you
will see how simple they are to interpret, as they are only a graphical representation, that is, drawings of the laptop circuits, where symbols that represent the various components that are on the motherboard.
Symbol and Screen Printing:
One of the main problems faced by those who begin to read electrical schematics is the identification of components and also of symbol.
The various letters and symbols (which may even vary according to the design they are applied to) sometimes become one of the biggest difficulties that technicians usually face when repairing their first laptops.
Every laptop motherboard is manufactured with letters on its surface that are located next to each component or region of a circuit, and that allow the technician to quickly identify what that component is about. They call it motherboard screen printing.
If you take a motherboard from a laptop you will notice that in addition to the description of the motherboard model, all components, be it resistor, diode, etc., have an identification that serves to help locate them in the wiring diagram.
Each component name found on the motherboard wiring diagram and screen must be unique. Ex: capacitor C1, C2, C3 and so on.
The following tables list some the main components used on a laptop's motherboard:
Just as screen printing is important for the motherboard, the symbol is for the electrical schematic.
Below are the main symbols used in the schematics of laptop:
