Identify the bus relationship
I2C uses data and clock signals commonly labelled SDA and SCL. A bus can connect multiple devices. Start by tracing those nets on a matching schematic rather than guessing function from a component’s physical position on the board.
Make an annotated device list
For a training exercise, list the devices connected to the two nets and identify their supply domains from documentation. Note any referenced pull-ups. This paper task helps reveal why a complaint associated with one device may require checking a shared path.
Separate identification from testing
Locating SDA and SCL does not establish that data is being exchanged correctly. Static readings have limits; timing and protocol interpretation may require appropriate equipment and expertise. Do not attach a generic adapter or force a signal onto an unfamiliar board. Ask the instructor what evidence would support the next diagnostic decision.
Several devices share the same nets
A shared-bus drawing helps explain why the apparent symptom may involve more than one participant. Keep every connected device in the annotated list. Locating a shared line does not establish which device or connection caused a failure.
Your practice record
- SDA and SCL traced
- Connected devices listed
- Supply and pull-up references
- Test limitations recorded
Sources and further reading
Manufacturer and technical references for the checks discussed in this guide. Follow the instructions for your exact device and equipment.
Repair procedures involve heat, electricity, fragile parts and customer data. Practise under qualified supervision and work only on devices you are authorized to service.
