0.00 → 0.15A+
No Power
DC draw → main rails → PMIC → reset → clock → CPU/storage handshake.
OPEN FLOW →
ANDROID TECHNICIAN CENTER
Diagnose the board.
Diagnose the board.
Follow the evidence.
Android hardware, storage and firmware diagnostics organized around what a technician actually sees: current draw, rails, USB modes, boot stage, storage identity, chipset family and partition state.
LIVE DIAGNOSTIC MAP
signal path
measurement point
state transition
01 — DIAGNOSTICS
Start from the fault symptom
Each category opens into a measurement-driven decision tree, not a generic article.
USB-C
BAT
Charging
VBUS → CC → USB switch/PHY → charge IC → battery ID/NTC → system rail.
OPEN FLOW →
S0S1S2OS
Boot / Restart
Boot stages, watchdogs, storage access, AVB, slots, kernel and thermal/sensor causes.
OPEN FLOW →
RF
MODEM
Network
SIM detect → modem power → RF rails → clocks → baseband communication → RF front-end.
OPEN FLOW →Display / Touch
Panel rails, reset, MIPI, touch bus, backlight and connector diode/reference values.
OPEN FLOW →
SOC
UFS
UFS / eMMC
Power, CLK/CMD/DAT, link startup, identity, health, LUN/boot areas and firmware evidence.
OPEN FLOW →
02 — STORAGE INTELLIGENCE
UFS / eMMC diagnostic map
Separate electrical health, protocol identity, firmware requirement and donor-compatibility evidence.
1Power railsVCC • VCCQ • VCCQ2
2Bus / linkCLK • CMD/DAT • M-PHY
3IdentityCID • descriptor • vendor • model
4HealthLifetime • pre-EOL • errors
5Firmware evidenceRequirement • host ceiling • device-keyed support
03 — CHIPSET WORKFLOWS
Five SoC families. Five different service architectures.
Select the actual chipset family before interpreting USB mode, loader state, storage initialization, security or recovery behavior.
Q
Qualcomm
PBL • EDL 9008 • Sahara • Firehose • Storage • GPT • AVB.
PBLSAHARAFIREHOSE
OPEN QUALCOMM →
M
MediaTek
BROM • Preloader • Auth • DA • EMI/DRAM • Storage • Scatter.
BROMDAEMI
OPEN MEDIATEK →
U
Unisoc
BootROM • FDL1 • DRAM • FDL2 • Storage • PAC • NV.
ROMFDL1FDL2
OPEN UNISOC →
E
Samsung Exynos
Boot chain • Download Mode • Odin • PIT • KG/Knox • CP/Baseband.
BOOTODINPIT
OPEN EXYNOS →
T
Google Tensor
Bootloader • Fastboot • AVB • A/B • Fastbootd • Dynamic Super.
FASTBOOTAVBSUPER
OPEN TENSOR →
04 — SERVICE MODES
EDL • BROM • FDL • Odin • Fastbootd
The port or service mode tells you how far the boot chain progressed. It does not by itself identify the failed component.
QUALCOMM
PBLBootROM stage
Saharaprogrammer handshake
Firehosestorage / GPT operations
MEDIATEK
BROMhardware BootROM
Preloader / DAauth + loader
EMI / StorageDRAM + storage init
UNISOC
BootROMinitial download state
FDL1internal SRAM loader
FDL2DRAM + storage operations
SAMSUNG EXYNOS
Boot ChainBL stages
Download ModeSamsung service state
Odin / PITsigned package + layout
GOOGLE TENSOR
Fastbootbootloader service
AVB / A-Bverification + slots
Fastbootddynamic partitions
05 — FIRMWARE & DYNAMIC PARTITIONS
Understand the image before you flash it
Dynamic partitions, AVB and slot state can turn a “successful flash” into a non-booting device.
super
systemvendorproductsystem_ext
Dynamic Partitions
Inspect super metadata, groups, partition sizes, slots and lpmake constraints.
OPEN DYNAMIC PARTITIONS →
vbmeta✓system✓vendor
AVB / vbmeta
Track verification relationships and mismatched image state before recovery attempts.
OPEN AVB / VBMETA →
A↔B
A/B Slot Health
Current slot, retry count, successful/unbootable state and slot-aware partition writing.
OPEN A/B SLOT INTELLIGENCE →
06 — REPAIR CASES
Bench evidence → conclusion
Case records should preserve measurements and failed assumptions, not only the final fix.
Dead board diagnostic case
0.012A→storage removed→USB mode appears→next rail test
View case archive →
Storage identity & health case
ID→health→boot areas→compatibility evidence
View case archive →
Boot / super / AVB case
slot→super→vbmeta→boot result
View case archive →