| 1 | DC Input | Adapter / DC-IN main rail | Input connector / protection path | Schematic p.43 | Follow chronological sequence | Board-specific adapter/input voltage; verify source/PD contract and schematic. | Measure DC to ground at the adapter/input protection path. | Flat DC; investigate collapse or excessive ripple. |
| 2 | Charger | ACOK / ACIN | Charger -> EC/SMC | Schematic p.43 | Follow chronological sequence | Valid adapter-present logic state when the source is accepted; polarity is board/IC specific. | Measure logic level and observe insertion/removal transition. | Clean state transition on adapter insertion/removal. |
| 3 | Always-On | 3V always-on / S5 rail | Always-on 3V rail | Schematic p.2 | Follow chronological sequence | Nominal rail voltage indicated by schematic rail name; verify tolerance from source. | Measure at rail coil/capacitor to ground. | Clean startup and stable DC. |
| 4 | Always-On | 5V always-on / S5 rail | Always-on 5V rail | Schematic p.2 | Follow chronological sequence | Nominal rail voltage indicated by schematic rail name; verify tolerance from source. | Measure at rail coil/capacitor to ground. | Clean startup and stable DC. |
| 5 | EC / SMC | EC / SMC supply | EC/KBC/SMC power | Schematic p.24 | Follow chronological sequence | Board-specific EC/SMC supply must be valid and stable. | Measure EC/SMC supply rails before expecting sequence outputs. | Flat DC; no repeated collapse. |
| 6 | EC / SMC | 32.768 kHz RTC / EC clock | RTC / EC low-frequency clock | Schematic p.24 | Follow chronological sequence | Stable low-frequency oscillation where the board exposes/measures it. | Oscilloscope with high-impedance probe; avoid loading crystal nodes. | ~32.768 kHz waveform when applicable. |
| 7 | Reset | RSMRST# | EC/SMC/PCH reset path | Schematic p.17 | Follow chronological sequence | Must release only after required standby power/clock conditions are met; polarity by signal suffix. | Measure logic level and transition during standby sequence. | Clean reset release. |
| 8 | Power Button | PWRBTN# / power switch | Button -> EC/SMC/PCH | Schematic p.17 | Follow chronological sequence | Expected active transition according to board polarity. | Observe logic transition while pressing the button. | Clean pulse on press/release. |
| 9 | Sleep State | SLP_S5# | PCH/SoC sleep state | Schematic p.17 | Follow chronological sequence | Must transition according to the board power-state sequence. | Measure logic state during attempted power-up. | Clean state transition. |
| 10 | Sleep State | SLP_S4# | PCH/SoC sleep state | Schematic p.17 | Follow chronological sequence | Must transition according to the board power-state sequence. | Measure logic state during attempted power-up. | Clean state transition. |
| 11 | Sleep State | SLP_S3# | PCH/SoC sleep state | Schematic p.17 | Follow chronological sequence | Must transition before dependent S0 rails are expected. | Measure logic state during attempted power-up. | Clean state transition. |
| 12 | Memory | Memory VDD / VDDQ | Memory power | Schematic p.2 | Follow chronological sequence | Nominal board-specific memory rail voltage for installed memory generation. | Measure rail voltage at memory coil/capacitors. | Stable DC with normal ramp. |
| 13 | CPU / SoC | VR_ON / CPU VR enable | EC/SMC/SoC -> CPU VR | Schematic p.46 | Follow chronological sequence | Board-specific active logic state when CPU core power is requested. | Measure enable logic at VR controller. | Clean assertion before core rail rise. |
| 14 | CPU / SoC | CPU VCORE | CPU core regulator output | Schematic p.2 | Follow chronological sequence | Dynamic CPU core voltage; exact value depends on platform and operating state. | Measure at CPU core inductor/output capacitors. | Observe controlled ramp; scope ripple if unstable. |
| 15 | CPU / SoC | CPU VR power-good / VR_RDY | CPU VR -> platform logic | Schematic p.46 | Follow chronological sequence | Asserted only after the VR output is within regulation; exact polarity/name is board specific. | Measure logic after core rail starts. | Clean delayed assertion. |
| 16 | CPU / SoC | SVID clock/data | CPU/SoC VR controller | Schematic p.7 | Follow chronological sequence | Digital activity during CPU voltage negotiation when supported. | Use oscilloscope; DMM is not diagnostic for bus activity. | Bursting clock/data activity. |
| 17 | Power Good | SYS_PWROK / ALL_SYS_PWRGD | Aggregate power-good logic | Schematic p.17 | Follow chronological sequence | Asserted only after required platform rails/power-good inputs are valid. | Measure logic after required rails are stable. | Clean delayed assertion. |
| 18 | Reset | PLTRST# / platform reset | PCH/SoC -> platform devices | Schematic p.17 | Follow chronological sequence | Released only after clocks, firmware and power-good prerequisites are satisfied. | Measure logic level and startup transition. | Clean reset release. |
| 19 | BIOS / SPI | BIOS / SPI flash supply | SPI flash supply | Schematic p.2 | Follow chronological sequence | Use exact flash marking/datasheet; commonly 1.8 V or 3.3 V but never assume. | Identify exact flash device first, then measure VCC. | Stable DC. |
| 20 | BIOS / SPI | SPI chip-select | Controller -> SPI flash | Schematic p.18 | Follow chronological sequence | Idle/inactive with access pulses when firmware is being read. | Oscilloscope during power-on/reset release. | Chip-select pulse bursts. |
| 21 | BIOS / SPI | SPI clock | Controller -> SPI flash | Schematic p.18 | Follow chronological sequence | Clock bursts during flash access. | Oscilloscope during firmware access. | High-frequency clock bursts. |
| 22 | Display | LCD / eDP panel power | Panel power switch -> connector | Schematic p.8 | Follow chronological sequence | Board-specific panel logic supply as shown in schematic. | Measure at panel connector/fuse/load switch. | Stable DC after panel enable. |
| 23 | Display | eDP HPD | Panel -> GPU/PCH/SoC | Schematic p.8 | Follow chronological sequence | Valid board-specific HPD state when panel is detected. | Measure HPD logic with panel connected and powered. | Clean logic level/transition. |
| 24 | Display | eDP AUX | GPU/PCH/SoC panel | Schematic p.8 | Follow chronological sequence | AUX transactions during panel detection/EDID/link setup. | Use oscilloscope/differential method suitable for AUX; avoid loading the bus. | Bidirectional AUX activity during display initialization. |
| 25 | Display | Backlight enable | EC/PCH/GPU -> backlight path | Schematic p.8 | Follow chronological sequence | Board-specific active state after panel initialization. | Measure enable logic when image/backlight should be active. | Clean assertion. |
| 26 | Display | Backlight PWM | EC/PCH/GPU -> backlight controller | Schematic p.24 | Follow chronological sequence | PWM activity when brightness is nonzero; exact frequency/duty is platform specific. | Use oscilloscope; measure duty/frequency. | Stable PWM waveform. |
| 27 | Battery | Battery SMBus | EC/charger battery | Schematic p.43 | Follow chronological sequence | Pulled-high idle with transaction bursts when battery is queried. | Use oscilloscope for clock/data activity; confirm pull-up rail. | I2C/SMBus clock/data bursts. |