3. Resistors

• What is a resistor?
• Working principle
• Types of resistors
• Carbon resistor
• Metal film resistor
• SMD resistor
• Variable resistor / potentiometer
• Resistor colour code
• SMD resistor markings
• Resistance measurement
• Resistor failure modes
• Pull-up resistor
• Pull-down resistor
• Current limiting resistor
• Voltage divider

4. Capacitors

• What is a capacitor?
• Working principle
• Capacitance
• Unit: pF, nF, µF
• Ceramic capacitor
• Electrolytic capacitor
• Tantalum capacitor
• SMD capacitor
• Polymer capacitor
• Polarized vs non-polarized capacitor
• Capacitor charging and discharging
• Filtering
• Decoupling
• Coupling
• Capacitor failure
• Shorted capacitor
• Leaking capacitor
• ESR concept

5. Inductors / Coils

• What is an inductor?
• Working principle
• Inductance
• Unit: Henry
• SMD coils
• Power inductors
• Chokes
• Ferrite beads
• EMI filtering
• Coil failure
• Open coil vs shorted coil

6. Diodes

• What is a diode?
• PN junction concept
• Forward bias
• Reverse bias
• Diode working principle
• Rectifier diode
• Schottky diode
• Zener diode
• TVS diode
• LED
• SMD diode identification
• Diode-mode testing
• Shorted diode
• Open diode

7. Transistors

• What is a transistor?
• BJT
• NPN
• PNP
• MOSFET
• N-Channel MOSFET
• P-Channel MOSFET
• Gate, Drain and Source
• MOSFET working principle
• MOSFET as a switch
• High-side MOSFET
• Low-side MOSFET
• MOSFET testing
• Common MOSFET failures

8. Voltage Regulation Components

• Voltage regulator concept
• Linear regulator
• LDO
• Switching regulator
• Buck converter
• Boost converter
• Buck-boost converter
• PWM controller
• Feedback circuit
• Reference voltage
• Enable signal

9. ICs

• What is an IC?
• Types of IC packages
• SMD IC identification
• Controller IC
• Power IC
• Charging IC
• Audio IC
• BIOS/Flash IC
• Embedded Controller
• Super I/O
• PWM IC
• PCH / chipset
• CPU/GPU basics

10. Transformers

• Transformer working principle
• Primary and secondary
• Step-up
• Step-down
• Isolation transformer
• SMPS transformer
• Transformer testing

11. How Electronic Circuits Work

Students should learn to follow a circuit logically:

Input → Protection → Switching → Regulation → Filtering → Load

Topics:

• Current path
• Voltage path
• Ground path
• Signal path
• Power rail
• Feedback
• Switching
• Regulation
• Filtering
• Protection circuits

Important concepts

• Pull-up / Pull-down
• Voltage divider
• Current limiting
• RC circuit
• LC filter
• Diode protection
• MOSFET switching
• Feedback circuit
• Enable signal
• Power-good signal
• Reset signal

12. Semiconductor Basics

• Conductor
• Insulator
• Semiconductor
• Silicon
• P-type semiconductor
• N-type semiconductor
• PN junction
• Electron and hole
• Doping
• Depletion region
• Forward bias
• Reverse bias

13. Transistor & MOSFET Theory

• Semiconductor switching
• BJT operation
• MOSFET operation
• Gate control
• Threshold voltage
• Drain-source resistance
• Body diode
• MOSFET switching losses
• MOSFET protection

This is very important for chip-level servicing.

14. SMPS Fundamentals

• What is SMPS?
• AC input
• Rectification
• Filtering
• Switching
• Transformer
• Secondary rectification
• Feedback
• Output filtering

Desktop SMPS

• AC input section
• Fuse
• MOV
• NTC
• Bridge rectifier
• Bulk capacitor
• PWM controller
• MOSFET
• Transformer
• Secondary diode
• Output capacitor
• Feedback circuit

Laptop Adapter

• Input section
• Primary side
• Secondary side
• Output voltage
• Protection
• Adapter identification

15. Desktop Motherboard Architecture

• Motherboard overview
• CPU section
• RAM section
• Chipset/PCH
• BIOS
• VRM
• PCIe
• USB
• SATA
• Audio
• LAN
• Display output
• Clock circuits
• Reset circuits
• Power sequencing

16. Laptop Motherboard Architecture

• Laptop motherboard overview
• DC-in section
• Charging section
• Battery circuit
• 3.3V / 5V rails
• CPU power
• RAM power
• BIOS
• EC/KBC
• PCH
• USB
• HDMI/DisplayPort
• Audio
• Wi-Fi
• Keyboard/touchpad
• Power button circuit

17. Understanding Motherboard Power Rails

Students should learn names such as:

• VIN
• B+
• +3VALW
• +5VALW
• +3VS
• +5VS
• CPU VCORE
• VCCSA
• VCCIO
• DDR voltage
• PCH voltage

Learn:

• What is a power rail?
• Always-on voltage
• Standby voltage
• Switching voltage
• CPU voltage
• RAM voltage
• Power sequencing
• Voltage enable signals
• Power-good signals

MODULE 9 — BIOS, EC/KBC & Firmware

18. BIOS

• What is BIOS?
• BIOS vs UEFI
• SPI Flash ROM
• BIOS chip identification
• BIOS power supply
• BIOS communication
• BIOS corruption
• BIOS programming
• BIOS backup
• BIOS flashing
• BIOS verification

19. EC / KBC

• What is Embedded Controller?
• KBC
• Keyboard controller
• Power button communication
• Battery management
• Fan control
• Charging control
• Power sequencing
• EC firmware basics

20. Schematic Reading

• What is a schematic?
• Component symbols
• Reference designators
• Net names
• Power rails
• Ground symbols
• IC pin numbers
• Connector identification
• Signal tracing
• Page-to-page connections
• Block diagrams
• Datasheet reference

Common reference designators

• R = Resistor
• C = Capacitor
• L = Inductor
• D = Diode
• Q = Transistor/MOSFET
• U = IC
• J = Connector
• F = Fuse
• Y = Crystal/Oscillator

21. Boardview

• What is Boardview?
• Component location
• Board coordinates
• Net tracing
• Finding components
• Finding power rails
• Finding ground
• Comparing schematic and boardview
• Tracing a fault from IC → component → rail

22. PCB Understanding

• What is PCB?
• Single-layer PCB
• Double-layer PCB
• Multilayer PCB
• Copper layers
• Ground plane
• Power plane
• Signal layer
• Vias
• Through-hole
• Blind via
• Buried via
• PCB traces
• Pads
• Test points

23. Soldering Fundamentals

• Soldering iron
• Solder wire
• Flux
• Solder paste
• Solder wick
• Solder sucker
• Tip selection
• Temperature control
• Through-hole soldering
• SMD soldering

24. Hot Air Rework

• Hot air station
• Temperature
• Airflow
• Nozzle selection
• Component removal
• Component replacement
• Avoiding PCB damage
• Avoiding lifted pads

25. Advanced Rework

• SMD component replacement
• MOSFET replacement
• IC replacement
• Connector replacement
• BIOS IC replacement
• Jumper work
• Pad repair
• Trace repair
• Via repair
• Jumper wire techniques

26. Practical Multimeter Diagnosis

• Voltage mode
• Resistance mode
• Continuity mode
• Diode mode
• Measuring capacitors
• Measuring coils
• Testing MOSFETs
• Testing diodes
• Checking short circuits
• Checking power rails

Important practical exercises

• Find short to ground
• Find shorted capacitor
• Find shorted MOSFET
• Check voltage rail
• Check resistance to ground
• Check diode-mode readings
• Compare good vs faulty board

27. Bench Power Supply

• What is a DC bench power supply?
• Voltage setting
• Current limit
• Current consumption
• Connecting motherboard safely
• Current draw analysis

Current consumption patterns

• 0.000A
• Very low current
• High current
• Pulsing current
• Current jumping up/down
• Current immediately hitting limit

Students learn how these patterns can indicate different fault areas.

28. Charging Section

• DC jack
• Input protection
• Fuse
• TVS
• Input MOSFET
• Charger IC
• Battery MOSFET
• ACOK
• Adapter detection
• Charging current
• Battery voltage
• Charging voltage
• Battery communication
• Charging faults

29. Power Sequence Troubleshooting

Teach the student to diagnose:

Adapter → Input Voltage → Protection → Charger IC → Standby Rails → EC → Power Button → BIOS → PCH/CPU → RAM → Display

Students should learn:

• Where voltage should appear
• What signal should appear
• What happens if a signal is missing
• How to identify the missing stage
• How to isolate the faulty circuit

30. No Power

• No charging
• No standby voltage
• Short circuit
• Faulty MOSFET
• Faulty charger IC
• BIOS problem
• EC problem
• Power button problem

31. No Display

• RAM
• BIOS
• CPU/GPU
• Display power
• Backlight
• LCD connector
• HDMI/eDP
• Display signals

32. Power On → Shutdown

• CPU power
• RAM power
• BIOS
• overheating
• short circuit
• power sequencing

33. Charging Problems

• Not charging
• Adapter not detected
• Battery not detected
• Charging stops
• Overcharging
• No battery power

34. Desktop Faults

• No power
• No POST
• No display
• Continuous restart
• RAM detection problem
• CPU power problem
• USB failure
• LAN failure
• Audio failure
• BIOS failure

35. Desktop VRM

• CPU VRM
• MOSFETs
• PWM controller
• Inductors
• Driver IC
• VCORE
• Phase configuration
• VRM troubleshooting

36. BGA Fundamentals

• What is BGA?
• BGA package
• Solder balls
• BGA failure
• Reflow vs reballing
• BGA removal
• BGA cleaning
• Reballing
• BGA replacement
• Risks of reflow

37. CPU / PCH / GPU

• Basic architecture
• Power requirements
• Clock
• Reset
• Communication
• CPU power rails
• PCH power rails
• GPU power rails
• Diagnosing CPU/PCH-related faults

38. Short-Circuit Finding

• Resistance method
• Diode-mode method
• Voltage injection
• Current injection
• Thermal detection
• IPA method
• Thermal camera
• Finding the heating component
• Isolating the short

39. Oscilloscope Basics

I strongly recommend including this in an advanced course.

• What is an oscilloscope?
• Voltage waveform
• Frequency
• Period
• Duty cycle
• Ripple
• Clock signal
• Reset signal
• PWM signal
• Checking crystal oscillator
• Checking power supply ripple

Students can gradually learn:

• Digital multimeter
• DC bench power supply
• Soldering station
• Hot air station
• Microscope
• LCR meter
• ESR meter
• Oscilloscope
• Thermal camera
• BIOS programmer
• SPI programmer
• BGA rework station

This should be the final stage of your course.

Give students faulty boards and make them follow a fixed troubleshooting procedure.

Practical 1

Dead Laptop

Student must identify:

1. DC input
2. Input fuse
3. MOSFET
4. Charger IC
5. 3.3V/5V standby
6. EC
7. BIOS
8. Power button
9. Power sequence

Practical 2

Short Circuit

Student must:

1. Check resistance
2. Check diode mode
3. Identify affected rail
4. Inject voltage safely
5. Find heating component
6. Replace component
7. Verify rail

Practical 3

No Display

Trace:

Power → BIOS → RAM → CPU/PCH → Display power → Display signal

Practical 4

Charging Fault

Trace:

DC Jack → Protection → MOSFET → Charger IC → Battery

Practical 5

No POST

Check:

Standby → Power sequence → CPU VRM → RAM → BIOS → Reset/Clock