Apple iPod photo classic 4th Generation White (20 GB)



- YHYZ Precision Tweezer ESD-12
- JRready ACT WN10 Wire Cutters Precision Flush Pliers 5 inch Precision Extensions for Hand Tool
- Uxcell Non-magnetic Curved Tip Tweezer Anti-static Stainless Steel Precision Multifunctional
- Economic long Round Nose Pliers
- Chrome Screw Driver

Use the Wire Cutter to pry up against the plastic front panel and release five retaining tabs

Headphone Jack and Hold Switch(820-1635-A)
Standard 3.5mm headphone jack. The material used for the headphone jack was typically metal, which provided durability and good electrical conductivity.

Hold Switch

Headphone Jack & Hold Switch Flex Cable(632-0260)
Flat Ribbon Cable: flat ribbon cable, which consists of multiple thin conductive wires sandwiched between layers of insulating material. The insulating material is made of a flexible plastic.
Connectors: At each end of the flex cable, there were connectors or plugs made of plastic or metal. These connectors allowed for the cable to be connected to the headphone jack and hold switch on one end and the main logic board on the other end.
Insulation: The cable also had insulating material to protect the conductive wires and prevent short circuits. This insulation was made of a flexible, durable plastic.

Hold button (plastic)
Plastic: Plastic is lightweight, durable, and can be molded into various shapes and sizes.

Hold button

White Plastic Dock Bezel

Rear case (stainless steel)

Hard drive cable

TUSHIBA hard drive MK2004GAL
Toshiba MK2004GAL 20GB UDMA/100 ATA-5 4200RPM 1.8″ Inch Mini Hard Drive
Hybrid (HDD/SSD)
DMA/ATA-100 (Ultra)
- Toshiba 20GB 1.8-inch Mini Hard Drive General Features: 20GB formatted capacity UDMA/100 transfer ratio.
- ATA-5 interface 2 MB buffer 4200 RPM spindle speed 7.14 ms average latency 15 ms average seek time.
- 1.8-inch form factor Low-power consumption Power Specifications: DC 3.3V 500mA Regulatory Approvals.

Logic board

Logic board and display


Apple 820-1535-A Logic Board
Fiberglass or PCB Material: The main substrate or base of the logic board is usually made of a fiberglass-reinforced epoxy laminate material, commonly referred to as a Printed Circuit Board (PCB).
Copper Traces: Conductive traces on the PCB are typically made of copper.
Solder: Solder is used to attach electronic components to the PCB. It typically contains a mixture of metals, including tin and lead.
Silicon Chips: The logic board houses various silicon chips, including the CPU (Central Processing Unit), GPU (Graphics Processing Unit), memory chips, and other integrated circuits. These chips are made from silicon.
Connectors and Ports: Connectors and ports on the logic board may be made from various materials, including plastic and metal.

LCD Display (F-51824FNF-SLM-AD)
(Looks like there’s some screen fluid leaking)
Plastic Front Cover: touch-sensitive surface for user interaction.
Liquid Crystal Layer: The core of the LCD screen is the liquid crystal layer, which is made of organic molecules that can change their orientation in response to an electric current. This layer is responsible for controlling the passage of light through the screen and creating the images and colors you see.
Backlight: LCD screens require the liquid crystal layer. The backlight is typically made up of small LEDs (Light Emitting Diodes). Include semiconductors and various types of plastics or glass for housing and diffusion.
Thin-Film Transistors (TFTs): TFTs are used to control the individual pixels on the LCD screen. (semiconductor materials, such as silicon)
Color Filters: To produce full-color displays, color filters are used in LCD screens.

LCD Display back

White Front Faceplate
Covered the front of the device and housed the screen, Click Wheel for navigation, and other controls.

Battery(616-0198)
Lithium-Ion Cells: The core of the Li-ion battery is the lithium-ion cell.
Anode (Negative Electrode): The anode in a Li-ion battery is made of carbon or graphite materials.
Cathode (Positive Electrode): The cathode is made of a lithium-based material, such as lithium cobalt oxide (LiCoO2) or other variations.
Electrolyte: The electrolyte is a crucial component that allows lithium ions to move between the anode and cathode during charge and discharge.
Separator: A separator is used to keep the anode and cathode from coming into direct. The separator is a porous material, such as a polymer.
Protection Circuit: Many replacement Li-ion batteries, especially for consumer electronics like iPods, include a protection circuit board (PCB).
Connectors: The battery often includes connectors for easy installation and connection to the device.


Front panel


Click wheel(657-0230)
The click wheel operates by sensing user input through its touch-sensitive ring, which can execute multiple commands thanks to four mechanical buttons positioned beneath it.
The primary technology at play in the click wheel is capacitive sensing technology. When an electrical voltage is applied across two conductors situated closely but not in direct contact, it results in the storage of energy in the form of an electric field. Even after the voltage is removed, the stored charge remains, illustrating how capacitors gather and retain energy.
In the case of the click wheel, this property of capacitors is harnessed to detect the position of the user’s finger due to the capacitance between the human body and the conductive film beneath the plastic cover of the click wheel.

Flex Cable( Foxconn 2604)
Connect the click wheel and logic board
Design elements that interest:
- Click Wheel: I appreciate the Click Wheel’s efficient scrolling and tactile feedback, which even includes a satisfying sound when pressed. It allows me to swiftly locate and choose what I want without the need for excessive button presses. When I try other music players for the first time, I often find that clicking their buttons can be uncomfortable and strain my fingers.
- iPod switch button:The switch button is a feature I frequently utilize on all Apple devices, although it functions differently on iPods compared to iPhones or iPads. iPods are more prone to accidental touches, but the switch button effectively addresses this issue. It simplifies the process of locking the screen and the wheel. Whether I place it in my pocket or any other location, it doesn’t negatively impact my user experience.