Fault · Power
No power
No display and no response to the power button. Check stage by stage, from the battery to the CPU.
View the guide steps online with your BoarDray account.
Covered on 180 models
- Samsung94With guide
- iPad43With guide
- iPhone43With guide
How to approach it
The battery powers the main line (VDD_MAIN) through the charger IC and its MOSFET. VDD_MAIN feeds the PMU, which first generates the always-on rails (ALWAYS and S4) and, when you press power, brings up the S2 (memory and I/O), S1 (CPU idle) and S0 (CPU, GPU and NAND) stages in order; then it releases reset and the CPU boots on its 24 MHz clock. Measure in that order: first unpowered (diode mode, looking for shorts), then with the power supply.
Other faults in Power
- Constant current draw, short or overheatingView fault
- Restarts or shuts downView fault
Where to find it
- By modelEach model lists the guides that apply to it.
- By familySamsung, iPad, and iPhone already have the guide.
Models where it is covered
Samsung · 94 models
iPad · 43 models
iPhone · 43 models
See inside every board
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