Chip Level Laptop Repairs: Understanding 3.3 & 5Volt Circuit

The 3.3 and 5V circuits are the fundamental components of a laptop's power structure. These voltages are generated by the motherboard as soon as the charger or battery is connected. These power supplies provide the voltage required to power various components such as the EC, Chipset reset power, power button (3.3v), bios chip (3.3v), charging communication (3.3v), and other s5 or voltages that remain active even when the laptop is turned off.

If there is a fault in the 3.3 and 5V circuits, the laptop will not function at all, including not charging or lighting up any LED indicators. It's important to note that this power architecture is used in all laptop devices, including major brands such as HP, Dell, Lenovo, and MacBook laptops.

Therefore, having a thorough understanding of these circuits and how they function will enable you to repair all laptop motherboards.

From the perspective of repairing, there are 2 known types of 3.3 and 5V circuits.

1. Single power supply

2. Separated power supply

Single power supply is the type of circuit where both 3.3 and 5V are made from one chip, well as separated is when each voltage has its own separate chip. This is very common in recent new laptops.

Identifying the 3.3 and 5 volts circuits on a laptop motherboard is crucial for effective diagnosis and repair. There are three methods to identify the 3.3 volt circuits:

• Identifying 3.3 and 5 Volts coils

Firstly, you can identify the 3.3 and 5 volts coils on the motherboard. Every coil on the motherboard is connected to the power supply and provides power to different sections of the motherboard. Typically, the coils are placed near the components they are powering. However, since the 3.3 and 5 volt circuits do not power a single component, they are usually independent and located near each other. By closely examining the motherboard, you can easily identify these coils.

• Checking the schematics diagrams

Secondly, you can check the schematics diagrams to identify the coils connected to the 3.3 and 5 volts circuits. If the coils are not easily identifiable, you can use the schematics diagrams to locate them on the motherboard. To learn more about reading and using schematics diagrams for laptop repairs, you can refer to a schematics course available on your account courses page.

• Measuring with a multimeter

Finally, if the laptop is still turning on or not short on the 19V rail, you can use a multimeter to measure and identify which coil is connected to the 3.3 and 5 volts circuits.

The 3.3 and 5 volts circuit on a laptop motherboard consists of five main components.

These components are:

Control chip:

This is responsible for regulating the voltage and ensuring that the circuit functions properly.

Coil:

The coil is responsible for converting the high voltage from the power supply into the lower voltage needed for the circuit.

Smoothing capacitors:

These are used to smooth out any fluctuations in the voltage and ensure that the circuit receives a consistent power supply.

Resistors:

These are used to limit the flow of electricity in the circuit and prevent damage to other components.

MOSFETs:

These are used to switch the circuit on and off and regulate the flow of electricity.

In some newer laptops, the MOSFETs are embedded in one chip, while in other motherboards, the MOSFETs are entirely embedded in the control chip

On a motherboard, there are different types of 3.3 and 5 volts that power various components such as the hard drive and USB ports. Specifically, the 3.3 and 5 volts chip generates four types of voltage:

• 3.3 Volts LDO,

• 3.3 Volts SO,

• 5 Volts LDO, and

• 5 Volts SO.

When power is supplied to the chip from the charger or battery, the chip releases 3.3 and 5V LDO. The 3.3 LDO voltage powers the EC and Chipset reset circuit. After pressing the power button, the EC sends a signal to the chip to start generating 3.3 and 5 SO volts. However, if the chip does not receive an enable signal, it will not generate SO voltages.

Once all the voltages are successfully generated, the chip sends a power good signal to the EC. If the EC does not receive this signal within the first few seconds after sending the enable signal, it may suspect a problem with the motherboard and turn off or repeatedly turn on and off the laptop or turn off the laptop completely.

The chip contains internal controllers that switch on and off two MOSFETs at a high speed to regulate the voltage output on the coil. To control the output voltage, the internal controller sends a pulse width modulation (PWM) signal to the MOSFET gates.

The internal controller is powered by 5 volts connected to VBST or Boot pins on the chip. If there is no power to VBST, the internal controller will not send gate signals, and there will be no voltage on the coils, even if enable signals are present.

In order for the MOSFETs to generate output voltage, there must be 19V on the drain of the high-side MOSFET and no short circuit present.

On a motherboard, there are different types of 3.3 and 5 volts that power various components such as the hard drive and USB ports. Specifically, the 3.3 and 5 volts chip generates four types of voltage:

• 3.3 Volts LDO,

• 3.3 Volts SO,

• 5 Volts LDO, and

• 5 Volts SO.

When power is supplied to the chip from the charger or battery, the chip releases 3.3 and 5V LDO. The 3.3 LDO voltage powers the EC and Chipset reset circuit. After pressing the power button, the EC sends a signal to the chip to start generating 3.3 and 5 SO volts. However, if the chip does not receive an enable signal, it will not generate SO voltages.

Once all the voltages are successfully generated, the chip sends a power good signal to the EC. If the EC does not receive this signal within the first few seconds after sending the enable signal, it may suspect a problem with the motherboard and turn off or repeatedly turn on and off the laptop or turn off the laptop completely.

The chip contains internal controllers that switch on and off two MOSFETs at a high speed to regulate the voltage output on the coil. To control the output voltage, the internal controller sends a pulse width modulation (PWM) signal to the MOSFET gates.

The internal controller is powered by 5 volts connected to VBST or Boot pins on the chip. If there is no power to VBST, the internal controller will not send gate signals, and there will be no voltage on the coils, even if enable signals are present.

In order for the MOSFETs to generate output voltage, there must be 19V on the drain of the high-side MOSFET and no short circuit present.

On a motherboard, there are different types of 3.3 and 5 volts that power various components such as the hard drive and USB ports. Specifically, the 3.3 and 5 volts chip generates four types of voltage:

• 3.3 Volts LDO,

• 3.3 Volts SO,

• 5 Volts LDO, and

• 5 Volts SO.

When power is supplied to the chip from the charger or battery, the chip releases 3.3 and 5V LDO. The 3.3 LDO voltage powers the EC and Chipset reset circuit. After pressing the power button, the EC sends a signal to the chip to start generating 3.3 and 5 SO volts. However, if the chip does not receive an enable signal, it will not generate SO voltages.

Once all the voltages are successfully generated, the chip sends a power good signal to the EC. If the EC does not receive this signal within the first few seconds after sending the enable signal, it may suspect a problem with the motherboard and turn off or repeatedly turn on and off the laptop or turn off the laptop completely.

The chip contains internal controllers that switch on and off two MOSFETs at a high speed to regulate the voltage output on the coil. To control the output voltage, the internal controller sends a pulse width modulation (PWM) signal to the MOSFET gates.

The internal controller is powered by 5 volts connected to VBST or Boot pins on the chip. If there is no power to VBST, the internal controller will not send gate signals, and there will be no voltage on the coils, even if enable signals are present.

In order for the MOSFETs to generate output voltage, there must be 19V on the drain of the high-side MOSFET and no short circuit present.

The main difference between a single 3.3 and 5 volts chip and separated 3.3 and 5 volts chips is that the single chip has both 3.3 and 5 volts integrated into one chip, whereas the separated chips have separate chips for each voltage. However, the operation and function of both single and separated chips are otherwise the same.

On a motherboard, there are different types of 3.3 and 5 volts that power various components such as the hard drive and USB ports. Specifically, the 3.3 and 5 volts chip generates four types of voltage:

• 3.3 Volts LDO,

• 3.3 Volts SO,

• 5 Volts LDO, and

• 5 Volts SO.

When power is supplied to the chip from the charger or battery, the chip releases 3.3 and 5V LDO. The 3.3 LDO voltage powers the EC and Chipset reset circuit. After pressing the power button, the EC sends a signal to the chip to start generating 3.3 and 5 SO volts. However, if the chip does not receive an enable signal, it will not generate SO voltages.

Once all the voltages are successfully generated, the chip sends a power good signal to the EC. If the EC does not receive this signal within the first few seconds after sending the enable signal, it may suspect a problem with the motherboard and turn off or repeatedly turn on and off the laptop or turn off the laptop completely.

The chip contains internal controllers that switch on and off two MOSFETs at a high speed to regulate the voltage output on the coil. To control the output voltage, the internal controller sends a pulse width modulation (PWM) signal to the MOSFET gates.

The internal controller is powered by 5 volts connected to VBST or Boot pins on the chip. If there is no power to VBST, the internal controller will not send gate signals, and there will be no voltage on the coils, even if enable signals are present.

In order for the MOSFETs to generate output voltage, there must be 19V on the drain of the high-side MOSFET and no short circuit present.

In this session, you will learn about the design of 3.3 and 5 volts circuits in different laptop brands. Most laptops use Intel processors, and the Intel chipset dictates the design of their motherboards. When Intel releases a new CPU, they provide engineers with datasheets and design guide documents containing recommendations and guidelines for designing motherboards that use their processors.

Manufacturers like HP, Dell, Asus, and others must follow these recommendations to ensure the processor works perfectly. As a result, different motherboards from different manufacturers may have the same components as long as they are of the same generation. This session will help you understand the relationship between Intel processors and laptop motherboard design, and how different manufacturers create their own unique 3.3 and 5 volts circuit designs while adhering to Intel's guidelines.

Attached are some of the Intel design guides and datasheet documents that you can download and take a look

In this session, you'll discover that MacBook motherboards that use Intel processors have many similarities with motherboards from other brands that use the same processor and generation. This is because the design of these motherboards is guided by Intel's chipset requirements.

In addition to following Intel's design guidelines, the principles of electronics also contribute to the similarities between these motherboards. As you delve deeper into the course, you'll gain a better understanding of how these factors come together to create motherboards that are similar across different brands, including MacBooks.

In this video, you'll learn about the common signs of a faulty 3.3 and 5 volts circuit in a laptop motherboard. These signs include:

• No life at all:

If the 3.3 and 5 volts circuit is faulty, the laptop will not turn on or show any signs of life, even when plugged in or charged.

• Charge but not turning on:

When the 3.3 and 5 volts chip can't make SO volts, the laptop will charge but won't turn on.

• Charger light going off:

If the 3.3 and 5 volts chip is short to ground, the adapter light will turn off when plugged into the laptop.

• Heating chip:

When the 3.3 and 5 volts chip has output short components, it will heat up when the charger is plugged in.

It's important to note that these symptoms can also be caused by other issues, so proper diagnosis is necessary before coming to a conclusion. In this upcoming videos, you'll gain the skills and knowledge needed to properly diagnose and repair faulty 3.3 and 5 volts circuits in laptop motherboards.

In this video, you'll explore the critical role that datasheets play in diagnosing and repairing faulty 3.3 and 5 volts circuits in laptop motherboards.

Datasheets are comprehensive technical documents that provide detailed information about the specifications, operation, and performance of electronic components, including chips used in laptop motherboards. By analyzing datasheets, you'll gain valuable insights into how chips work and the specific characteristics of each pin.

As you know not all motherboards have schematics diagrams datasheet help us to fix motherboard issues without schematics diagrams.

By studying the datasheet for the 3.3 and 5 volts chip, you'll learn about the various pins and functions, including the input and output voltages, current ratings, and timing requirements. You'll also discover the specific processes and stages involved in powering up the chip and other components on the motherboard.

When working with 3.3 and 5-volt chips like the TPS51225, it's important to understand the different pin functions. This understanding will enable you to fix various chips. Here are the most common pin functions:

• VIN: This pin powers up the chip by connecting it to a 19-volt power source.

• EN: This pin turns on the chip to start producing voltage. If there is no voltage on this pin, the chip will not produce voltage. Some chips have two enable pins: one for turning on the LDO voltage and another for SO. In other chips, this pin is called "ON."

• VBST: This pin powers the internal voltage controller that controls the turning on and off of the MOSFETs to make output voltage. This chip should have 5 volts as long as 19 volts is connected and LDO has no short circuit. This pin is sometimes called VBS or BOOT in other chips.

• LDO: This pin produces the LDO voltage, which is the first voltage to turn on when the 19-volt power source is connected to the chip. Some chips have a separate enable pin specifically for LDO voltage, which should have 3.3 volts for the LDO voltage to turn up. In other chips, this pin is called VREG.

• PG: This pin sends a power good signal to the EC to inform it that the 3.3 and 5 volts have successfully turned on. This is the last pin to turn on and will release 3.3 volts when all the voltages are up.

• PHASE: This pin is connected to the coil and is sometimes called LX and SW in other chips.

• DRVH: This pin is connected to the gate of the high-side MOSFET, which is the MOSFET connected to the 19-volt power source. This pin is not available in chips that have integrated MOSFETs.

• DRVL: This pin is connected to the gate of the low-side MOSFET, which is the MOSFET connected to the ground. This pin is not available in chips that have integrated MOSFETs.

• SKIPSEL: This pin determines the current limit for the SO voltage. It is connected to a resistor with a specific value that should not deviate. This pin is sometimes referred to as ILIM, which stands for Current Limit, where "I" represents current in Ohm's Law. In other chips, it may be labeled as CS, which stands for Current Sensor.

• VFB: Voltage Feedback is the pin that informs the chip's 3.3V and 5V rails that the SO voltage has successfully turned on. The output voltage is divided by a series resistor combination and fed back to the chip. This pin may be labeled as OUT or FF in other chips.

• GND: This pin is connected to the motherboard's ground.

When working with 3.3 and 5-volt chips like the TPS51225, it's important to understand the different pin functions. This understanding will enable you to fix various chips. Here are the most common pin functions:

• VIN: This pin powers up the chip by connecting it to a 19-volt power source.

• EN: This pin turns on the chip to start producing voltage. If there is no voltage on this pin, the chip will not produce voltage. Some chips have two enable pins: one for turning on the LDO voltage and another for SO. In other chips, this pin is called "ON."

• VBST: This pin powers the internal voltage controller that controls the turning on and off of the MOSFETs to make output voltage. This chip should have 5 volts as long as 19 volts is connected and LDO has no short circuit. This pin is sometimes called VBS or BOOT in other chips.

• LDO: This pin produces the LDO voltage, which is the first voltage to turn on when the 19-volt power source is connected to the chip. Some chips have a separate enable pin specifically for LDO voltage, which should have 3.3 volts for the LDO voltage to turn up. In other chips, this pin is called VREG.

• PG: This pin sends a power good signal to the EC to inform it that the 3.3 and 5 volts have successfully turned on. This is the last pin to turn on and will release 3.3 volts when all the voltages are up.

• PHASE: This pin is connected to the coil and is sometimes called LX and SW in other chips.

• DRVH: This pin is connected to the gate of the high-side MOSFET, which is the MOSFET connected to the 19-volt power source. This pin is not available in chips that have integrated MOSFETs.

• DRVL: This pin is connected to the gate of the low-side MOSFET, which is the MOSFET connected to the ground. This pin is not available in chips that have integrated MOSFETs.

• SKIPSEL: This pin determines the current limit for the SO voltage. It is connected to a resistor with a specific value that should not deviate. This pin is sometimes referred to as ILIM, which stands for Current Limit, where "I" represents current in Ohm's Law. In other chips, it may be labeled as CS, which stands for Current Sensor.

• VFB: Voltage Feedback is the pin that informs the chip's 3.3V and 5V rails that the SO voltage has successfully turned on. The output voltage is divided by a series resistor combination and fed back to the chip. This pin may be labeled as OUT or FF in other chips.

• GND: This pin is connected to the motherboard's ground.

When diagnosing short 3.3 and 5 volts chip issues on a motherboard, there are several steps you can take to efficiently troubleshoot the issue. Here are the steps in order:

• Measure voltage starting from the output coil, 19V vin input, LDO output, Enable pins, VBST pins and current pins.

• Measure for continuity starting from the coil, 19V vin input, LDO output, VBST pins and MOSFET gates.

• Measure all pins in continuity mode while referencing the schematics or datasheet to determine which pin is short to ground.

• Use the isolation method to separate the output and use voltage injections to identify which component is short to ground.

• If necessary, refer to my short circuit course for more detailed information.

Here are the steps broken down in more detail:

1. Check for voltage on the output coil. If you see 3.3 and 5 volts, that means the chip is working. If not, move on to step 2.

2. Measure voltage on the vin pin. You should get 19 volts. If you don't get 19V on this pin, disconnect the charger and measure the pin in continuity mode. If you hear a beeping sound, that indicates a 19V rail short circuit. If not, check the charger socket and input MOSFETs.

3. Measure the LDO pins - Check the voltage on the LDO pins. If you get the expected 3.3 and 5 volts, the LDO is working correctly. If not, move to the next step.

4. Remove the charger and measure LDO pins in continuity mode - Disconnect the charger and check for continuity using a multimeter. If you get a beeping sound, this indicates a short circuit. If there is no continuity, move to the next step.

5. Measure enable pin voltage - Check the voltage on the enable pins. If you do not get 3.3 volts on the LDO pins, this indicates that the chip is not being commanded to turn on. Check the source of the enable signal. If you do get 3.3 volts on the enable pin but no output, move to the next step.

6. Check VBST voltage - Check the voltage on the VBST pin. If you get voltage on the VBST pin, this is a good sign. If you do not get voltage, it may indicate a faulty chip. However, before coming to any conclusion, move to the next step.

7. Disconnect outputs and measure pins again - Disconnect the outputs such as the coil and LDO pins and check the voltage on the pins again. If nothing changes, move to the next step.

8. Use the power supply voltage injection method - Inject an appropriate voltage using the power supply voltage injection method and monitor the current being drawn. The output that consumes more current has a short component. Look for the component that is heating up more than others, as it may be the faulty component.

When diagnosing no short 3.3 and 5 volts chip issues on a motherboard, these are the steps to follow

1. Check for voltage on the output coil. If you see 3.3 and 5 volts, that means the chip is working. If not, move on to step 2.

2. Measure voltage on the vin pin. You should get 19 volts. If you don't get 19V on this pin, disconnect the charger and measure the pin in continuity mode. If you hear a beeping sound, that indicates a 19V rail short circuit. If not, check the charger socket and input MOSFETs.

3. Measure the LDO pins - Check the voltage on the LDO pins. If you get the expected 3.3 and 5 volts, the LDO is working correctly. If not, move to the next step.

4. Remove the charger and measure LDO pins in continuity mode - Disconnect the charger and check for continuity using a multimeter. If you get a beeping sound, this indicates a short circuit. If there is no continuity, move to the next step.

5. Measure enable pin voltage - Check the voltage on the enable pins. If you do not get 3.3 volts on the LDO pins, this indicates that the chip is not being commanded to turn on. Check the source of the enable signal. If you do get 3.3 volts on the enable pin but no output, move to the next step.

6. Check VBST voltage - Check the voltage on the VBST pin. If you get voltage on the VBST pin, this is a good sign. If you do not get voltage, it may indicate a faulty chip. However, before coming to any conclusion, move to the next step.

7. Disconnect outputs and measure pins again - Disconnect the outputs such as the coil and LDO pins and check the voltage on the pins again. If nothing changes, move to the next step.

8. Use the power supply voltage injection method - Inject an appropriate voltage using the power supply voltage injection method and monitor the current being drawn. The output that consumes more current has a short component. Look for the component that is heating up more than others, as it may be the faulty component.

When troubleshooting 3.3 and 5 volts chip issues, one of the common problems is missing 19 volts. There are three methods that can be used to trace the missing voltage:

• Check for Short

Short circuits are a common cause of missing voltage. When there is a short in the rail, the voltage will be dropped to zero. Therefore, the first step should be to measure the rail in continuity mode and ensure there are no short circuits.

• Broken Connections

Broken pads can also cause missing 19 volts. If any part of the rail is broken, the voltage will not reach its destination. In such a situation, one should observe the rail's condition and measure it in continuity mode to confirm that there is still a connection between the power source and the chip. The power source could be any component that supplies voltage to the chip, such as a diode or MOSFET.

• Broken Fuse

Blown fuses are another common problem on motherboards. Some fuses get blown due to age, while others are due to high currents or short circuits. It is always important to check the working state of the fuse connected to the 19V rail.

While tracing for 19 volts, one can follow the rails, measure them in continuity to determine where they are connected or use schematics to identify where the voltage comes from. To diagnose this issue faster, it is recommended to diagnose going backward. If the voltage is missing, one should check where it is meant to come from. By following these methods, you can easily identify and fix the problem of missing 19 volts on 3.3 and 5 volts chip

Enable signals can be turned on in two ways:

1. Voltage divider resistor combination - This type of enable voltage is common in LDO enable signals. By closely following the enable rail on the motherboard or in the schematics, you can discover the source of the signal.

2. EC (Embedded Controller) - After being powered on by the LDO volts, the EC will send an enable voltage. In some motherboards, the SO (System on) enable turns on automatically while in others, it turns on after pressing the power button.

To fix an enable signal issue, the following steps can be taken:

1. Trace the enable signal from its source - This will help determine where the issue is originating.

2. Check for any shorts - Make sure that the line carrying the enable signal has no short.

3. Check the source - Ensure that the source of the enable signal is powered on and in good condition to send the enable signal.

4. Check for rapid on-off cycles - In rare cases, the enable signal may turn on and off very quickly. To observe this, connect a multimeter and monitor its screen while pressing the power button or plugging in the charger.

The VBST pin serves as the power source for the internal controller that is responsible for turning the MOSFETs on and off. Typically, this voltage is 5 volts, and it will turn on immediately once 19V input voltage is plugged in.

However, there are conditions where VBST may fail to turn on, and one of these conditions is when there is a short circuit on the LDO output. If there is a short circuit on the LDO output, it can cause the LDO to shut down, which will, in turn, cause VBST not to turn on. It is important to identify and rectify any short circuit issues on the LDO output to ensure that VBST can turn on and power the internal controller.

When diagnosing issues with the 3.3 and 5v chips, the goal is to restore the laptop to its working condition. If you have successfully diagnosed the chip and confirmed that it is faulty, the next step is to find a replacement chip and replace it.

There are various ways to obtain a replacement chip, but two methods are commonly used. One approach is to source replacement chips from donor boards, which is fast and cost-effective. However, the challenge lies in collecting relevant donor boards. The best way to obtain these boards is by purchasing or asking failed boards from customers or fellow technicians. Donor boards can also be bought from online websites.

When searching for a replacement chip from donor boards, it's essential to consider the processor type and generation. Most laptop motherboards with the same processor generation tend to have similar chips. To determine compatible chips, it's best to compare the chip ID number. This method works well as the first chip number is always the chip ID. However, some new chips have hidden IDs, making it necessary to get their true ID from schematic diagrams. An efficient method is to search for replacement chips from the donor board schematic diagrams since looking at the motherboard takes time.

Another option to get a replacement chip is to buy one from suppliers. There are online websites like eBay, Amazon, AliExpress, Mouser, and many others where you can buy these chips. However, some chips may not be available on the internet, making donor boards the best option in such situations.

Getting replacement chips can be challenging, but it is made impossible by the companies that manufacture laptops. These companies dislike the fact that laptops are repaired, and sometimes they make it challenging for technicians to repair them. Regardless, we are here to fix laptops, and we will continue to do our best.

When obtaining replacement chips from donor boards, it's essential to test them before unsoldering them. Doing so will save time and effort because if you extract and replace a chip and find out that the replacement is also faulty, it can be frustrating.

To test the chip, there are a few methods to follow. Firstly, check for a short circuit in continuity mode using a multimeter and test the output coil, 19V VIN input pin, LDO output pins, VBST, and MOSFET gates.

Next, disconnect the output from the chip by unsoldering the coil and LDO jumpers. Connect 19V to the VIN pin; this should make the LDO output and VBST voltage appear, indicating that the chip is working. Remember to check for Enable, and if the LDO has an enable pin, connect the 3.3 volts for the LDO voltage to come up.

Finally, check the MOSFETs by testing their gates in continuity mode to ensure that there is no short circuit. By following these methods, you can verify that the replacement chip from the donor board is working correctly before soldering it onto the motherboard.

When replacing the 3.3 and 5-volt chips on a motherboard, there are a few things to keep in mind to ensure a successful repair. Firstly, it is crucial to consider the quality of the soldering station being used, as a substandard one can create a mess of the experience.

Next, the temperature of the soldering station is also essential. Most good soldering stations are within 500W and have the option to set the temperature up to 500 degrees Celsius. The size of the chip being replaced is also a factor to consider, as it will determine the temperature setting required. Small and medium-sized chips can be unsoldered easily between 330 to 370 degrees Celsius.

Another thing to consider is the output air of the soldering station, as it is the hot air that heats up the motherboard and melts the solder to enable the chip to be removed or attached. Most soldering stations have an air setting scale from 1 to 8, and based on experience, setting the air to the maximum with a temperature of 340 Celsius works well when soldering 3.3 and 5-volt chips.

The size of the nozzle used in the soldering station also determines how much temperature and air to set. For beginners, it is recommended to use the medium-sized nozzle, which projects heat in a concentrated area without burning other plastic connectors on the motherboard. After gaining some experience, one may remove the nozzle.

When soldering, it is good to apply flux to lubricate the chip and motherboard and enable the solder to dissolve well with the chip pins. During soldering, the nozzle should be wiggled and rotated around the chip for at least 1 minute after realizing that the nearby area has heated up. Then, focus more on the chip for 30 seconds and try to lift it off. If it is still hard, wiggle around the chip for another minute and focus on the chip again for 30 seconds before trying to lift it up. Repeat this process until the chip comes off. If the chip fails to come off, increasing the temperature and getting the nozzle closer to the chip may help.

It is essential to remember to reapply flux whenever it dries up. Another option to consider is using a preheater that distributes temperature from the bottom side of the motherboard. The preheater is suitable for delicate or big motherboard components, but it takes more time to do a simple thing that can be done quickly with a soldering station.

When replacing a chip, it's a good idea to use low melt solder on both the chip pins and the motherboard pins. This type of solder has a lower melting point, which means it will melt faster and make the process easier.

Lastly, soldering is a skill that takes time to master, and it is only mastered as a result of practice.

In this video, we will demonstrate how to diagnose and repair a faulty laptop by identifying and replacing a damaged chip. By following the schematic diagrams and techniques we have previously learned, you can apply this same knowledge to any other chip on the motherboard. We highly recommend watching this video closely and possibly reviewing it again to gain a thorough understanding of each step and action taken during the repair process. By doing so, you will be better equipped to tackle similar issues with confidence.