Understanding First
Understand the circuit before you touch the board
Instruments linked to reviewed real circuit diagrams -- choose a device, trace a path by its real name, place the probes where they belong, and watch how a diagnosis is actually built. Training for understanding, not a measurement tool on real hardware.
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Need a 10k resistor? Which board has one?
New at YallaMobile: a schematic index of resistors, capacitors and inductors. Search a value or reference to find the board, connections and related IC before choosing a donor.
Daily review of additions · Every value linked to its source
How the experience works
- 01
Choose a device
Start from the reviewed catalog of devices and circuits -- not every phone, only the ones with documented source coverage.
- 02
Trace a named path
Every net in the Circuit Lab keeps its real name from the source diagram -- trace it visually exactly as it appears on the original board.
- 03
Place the probes
Use the linked multimeter or oscilloscope to place probes on recorded points, with their original label and value -- nominal vs. measured, never blurred.
- 04
Learn the diagnosis
Follow the Phone Startup or charging-circuit sequence to see how a fault hypothesis is built from evidence -- with no promise of a guaranteed diagnosis.
See the signal. Understand the story.
From communication pulses to power switching: three oscilloscope views from the lab. These are adjustable teaching simulations, not live phone measurements.
I²C · Clock meets data
Read clock and data together. Follow the start of a message, its byte and the ACK response.
Buck · Before the output inductor
See the SW node before the inductor and distinguish it from the filtered output voltage.
Boost · Under light load
Recognize the switch-on interval, inductor discharge and ringing in this discontinuous-conduction example.
Real screenshots from inside the Academy
What's inside today
The catalog exposes only the reviewed teaching scope. Coverage per device is bounded strictly by its reviewed sources -- never more.
Source boundaries (mainboard vs. subboard) and the distinction between nominal and measured values survive unchanged from the source, with no simplification.
Four ways to understand the board
Component index
Search resistors, capacitors and inductors by value or reference. Find donor candidates across reviewed boards.
Devices & Circuits
Browse the available devices and every documented circuit inside them, with its real status.
Circuit Lab
An interactive component and path map, with a multimeter and oscilloscope linked to the source diagram.
Phone Startup
A teaching sequence through the boot stages, from base power to the display, built strictly from reviewed evidence.