TCS Pune

820-01814 – Bench Power & Signal Checklist

Board-specific bench checklist derived from supplied schematic source(s) for 820-01814 1.0.0. Only signals located in the supplied schematic text were added automatically; missing thresholds or values remain technician-verified rather than guessed.

V4.7 · REVISION SAFETY

820-01814 · Rev 1.0.0

Verify the physical motherboard revision before using this checklist. Measurements, component values and power circuitry can change between revisions.

Only one published revision is currently stored for this board. Verify the silkscreen before proceeding.

🔌 820-01814Expert⏱ 60-180 minutes📋 5 steps

Compatible models: SAFFORO / 051-02888

⚠ Safety: Disconnect battery before resistance/diode checks. Use current limiting for injection. Never inject voltage into an unknown rail until its safe voltage/current limit and isolation path are confirmed. Verify board/revision before using reference values.

🛠 Required Tools

  • Digital multimeter Oscilloscope with x10 probe Bench power supply with current limit Thermal camera / freeze spray as required SPI programmer where firmware diagnosis is required
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Schematic-derived bench record

Bench Manual & Source Coverage

Source coverage: High. Values and thresholds must still be verified against the exact schematic/datasheet.

Source PDF(s): 820-01814 (SAFFORO) Circuit diagram.pdf | 820-01814 Location map en.pdf | 820-01814 Physical scanning image .pdf

Board profile

Power & Control Architecture

Platform / ODMApple MLB
CPU / SoCIntel Skylake-H platform
PCH / ChipsetIntel PCH
MemoryDDR4
EC / SIOApple SMC
GPUDiscrete GPU platform
Table A

Chronological Power Sequence

Follow upstream to downstream. A missing later signal may simply be the result of an earlier missing prerequisite.

#StageSignal / RailFrom -> ToRefStateExpectedDMMOscilloscope
1DC InputAdapter / DC-IN main railInput connector / protection pathSchematic p.50Follow chronological sequenceBoard-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.
2Always-On3V always-on / S5 railAlways-on 3V railSchematic p.9Follow chronological sequenceNominal rail voltage indicated by schematic rail name; verify tolerance from source.Measure at rail coil/capacitor to ground.Clean startup and stable DC.
3EC / SMC32.768 kHz RTC / EC clockRTC / EC low-frequency clockSchematic p.74Follow chronological sequenceStable low-frequency oscillation where the board exposes/measures it.Oscilloscope with high-impedance probe; avoid loading crystal nodes.~32.768 kHz waveform when applicable.
4ResetRSMRST#EC/SMC/PCH reset pathSchematic p.9Follow chronological sequenceMust 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.
5Power ButtonPWRBTN# / power switchButton -> EC/SMC/PCHSchematic p.9Follow chronological sequenceExpected active transition according to board polarity.Observe logic transition while pressing the button.Clean pulse on press/release.
6Sleep StateSLP_S5#PCH/SoC sleep stateSchematic p.9Follow chronological sequenceMust transition according to the board power-state sequence.Measure logic state during attempted power-up.Clean state transition.
7Sleep StateSLP_S4#PCH/SoC sleep stateSchematic p.9Follow chronological sequenceMust transition according to the board power-state sequence.Measure logic state during attempted power-up.Clean state transition.
8Sleep StateSLP_S3#PCH/SoC sleep stateSchematic p.9Follow chronological sequenceMust transition before dependent S0 rails are expected.Measure logic state during attempted power-up.Clean state transition.
9MemoryMemory VDD / VDDQMemory powerSchematic p.5Follow chronological sequenceNominal board-specific memory rail voltage for installed memory generation.Measure rail voltage at memory coil/capacitors.Stable DC with normal ramp.
10CPU / SoCVR_ON / CPU VR enableEC/SMC/SoC -> CPU VRSchematic p.66Follow chronological sequenceBoard-specific active logic state when CPU core power is requested.Measure enable logic at VR controller.Clean assertion before core rail rise.
11CPU / SoCCPU VCORECPU core regulator outputSchematic p.7Follow chronological sequenceDynamic 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.
12CPU / SoCCPU VR power-good / VR_RDYCPU VR -> platform logicSchematic p.90Follow chronological sequenceAsserted only after the VR output is within regulation; exact polarity/name is board specific.Measure logic after core rail starts.Clean delayed assertion.
13Power GoodSYS_PWROK / ALL_SYS_PWRGDAggregate power-good logicSchematic p.9Follow chronological sequenceAsserted only after required platform rails/power-good inputs are valid.Measure logic after required rails are stable.Clean delayed assertion.
14ResetPLTRST# / platform resetPCH/SoC -> platform devicesSchematic p.9Follow chronological sequenceReleased only after clocks, firmware and power-good prerequisites are satisfied.Measure logic level and startup transition.Clean reset release.
15BIOS / SPIBIOS / SPI flash supplySPI flash supplySchematic p.12Follow chronological sequenceUse 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.
16BIOS / SPISPI chip-selectController -> SPI flashSchematic p.9Follow chronological sequenceIdle/inactive with access pulses when firmware is being read.Oscilloscope during power-on/reset release.Chip-select pulse bursts.
17BIOS / SPISPI clockController -> SPI flashSchematic p.9Follow chronological sequenceClock bursts during flash access.Oscilloscope during firmware access.High-frequency clock bursts.
18DisplayLCD / eDP panel powerPanel power switch -> connectorSchematic p.12Follow chronological sequenceBoard-specific panel logic supply as shown in schematic.Measure at panel connector/fuse/load switch.Stable DC after panel enable.
19DisplayeDP HPDPanel -> GPU/PCH/SoCSchematic p.12Follow chronological sequenceValid board-specific HPD state when panel is detected.Measure HPD logic with panel connected and powered.Clean logic level/transition.
20DisplayeDP AUXGPU/PCH/SoC panelSchematic p.2Follow chronological sequenceAUX transactions during panel detection/EDID/link setup.Use oscilloscope/differential method suitable for AUX; avoid loading the bus.Bidirectional AUX activity during display initialization.
21DisplayBacklight enableEC/PCH/GPU -> backlight pathSchematic p.12Follow chronological sequenceBoard-specific active state after panel initialization.Measure enable logic when image/backlight should be active.Clean assertion.
22DisplayBacklight PWMEC/PCH/GPU -> backlight controllerSchematic p.78Follow chronological sequencePWM activity when brightness is nonzero; exact frequency/duty is platform specific.Use oscilloscope; measure duty/frequency.Stable PWM waveform.
23USB-C / PDUSB-C CC1 / CC2USB-C port -> PD controllerSchematic p.29Follow chronological sequenceValid CC attachment/orientation state; exact voltage depends on source/sink role and Rp/Rd.Measure CC states according to Type-C/PD controller datasheet and port orientation.Observe attach/orientation changes.
24USB-C / PDPD negotiation / contractUSB-C PD controllerSchematic p.90Follow chronological sequenceContract may be 5/9/15/20 V or PPS depending platform/source; do not assume 20 V.Verify 5 V default VBUS first, then observe negotiation and final contract.PD communication / VBUS transition when negotiation succeeds.
Table B

Bench Reading & Fault Isolation

Enter the actual DMM reading and scope/logic observation. Select PASS, FAIL or N/A, then tick Checked when that row is complete.

0 / 24 checked
Checked#Signal / RailMeasuredObserved Waveform / LogicResultFailure Isolation HintTechnician Notes
1Adapter / DC-IN main railSchematic p.50No input: inspect adapter/port, fuse, protection MOSFETs and shorted PBUS/system rail.
Additional readings
Technician evidence
23V always-on / S5 railSchematic p.9Missing: inspect always-on controller enable/input, shorted load and power-good prerequisites.
Additional readings
Technician evidence
332.768 kHz RTC / EC clockSchematic p.74Absent clock: verify oscillator supply, crystal network and controller state.
Additional readings
Technician evidence
4RSMRST#Schematic p.9Held reset: work backward through always-on rails, RTC/clock, EC/SMC and PCH/SoC prerequisites.
Additional readings
Technician evidence
5PWRBTN# / power switchSchematic p.9No transition: inspect button, connector, pull-up and EC/SMC input path.
Additional readings
Technician evidence
6SLP_S5#Schematic p.9No transition: verify RSMRST#, firmware state, EC/SMC handshake and PCH/SoC prerequisites.
Additional readings
Technician evidence
7SLP_S4#Schematic p.9If missing, work backward through S5 prerequisites and firmware/EC handoff.
Additional readings
Technician evidence
8SLP_S3#Schematic p.9If missing, check upstream sleep-state logic, EC/SMC and platform power-good.
Additional readings
Technician evidence
9Memory VDD / VDDQSchematic p.5Missing/low: inspect memory VR enable, short/load and power-state prerequisite.
Additional readings
Technician evidence
10VR_ON / CPU VR enableSchematic p.66Missing: do not condemn VR controller; trace upstream sleep/power-good/EC logic.
Additional readings
Technician evidence
11CPU VCORESchematic p.70 V with valid enable: inspect VR input, controller, phases, current limit and rail resistance.
Additional readings
Technician evidence
12CPU VR power-good / VR_RDYSchematic p.90Missing: investigate VR feedback/phase faults/overcurrent and rail stability.
Additional readings
Technician evidence
13SYS_PWROK / ALL_SYS_PWRGDSchematic p.9Missing: identify the upstream rail or PGOOD that has not completed.
Additional readings
Technician evidence
14PLTRST# / platform resetSchematic p.9Held reset: verify firmware/SPI activity, clocks, SoC/PCH rails and PWROK chain.
Additional readings
Technician evidence
15BIOS / SPI flash supplySchematic p.12Wrong/missing supply: inspect flash power switch/rail and shorts before programming.
Additional readings
Technician evidence
16SPI chip-selectSchematic p.9No activity: sequence may not have reached firmware fetch; verify upstream reset/clock/power first.
Additional readings
Technician evidence
17SPI clockSchematic p.9CS activity without clock suggests bus/controller issue; no bus activity may be upstream sequencing.
Additional readings
Technician evidence
18LCD / eDP panel powerSchematic p.12Missing: inspect panel enable, fuse/load switch, shorted cable/panel and upstream display prerequisites.
Additional readings
Technician evidence
19eDP HPDSchematic p.12Missing: inspect panel power, cable/connector and HPD path.
Additional readings
Technician evidence
20eDP AUXSchematic p.2No AUX with power/HPD valid: inspect cable, panel and source path; do not infer GPU fault from one reading.
Additional readings
Technician evidence
21Backlight enableSchematic p.12Missing: inspect lid/Hall state, display initialization, firmware and control path.
Additional readings
Technician evidence
22Backlight PWMSchematic p.78Missing PWM with enable present: inspect brightness control source and firmware/EC path.
Additional readings
Technician evidence
23USB-C CC1 / CC2Schematic p.29Abnormal state: inspect port, ESD/protection, pull networks and PD controller supply before IC replacement.
Additional readings
Technician evidence
24PD negotiation / contractSchematic p.90No contract: verify CC state, controller supply, dead-battery path, firmware and source/cable compatibility.
Additional readings
Technician evidence
V4.0 · BOARD COMPONENT INTELLIGENCE

Component Index

Select a board component to see its function, related rails/signals, enable and power-good dependencies, input/output path, matching checklist tests and identical fitted ICs found on other board checklists. Unknown values are left unknown rather than guessed.

V4.3 Bench PSU Current Profile

Board Current Sequence

Record current draw in amperes at each observable stage. Historical comparison uses successful repairs of this exact board checklist. A different reading is a clue, not a component diagnosis.

Current sequence: No readings yet
No successful-repair baseline yet
No successful-repair baseline yet
No successful-repair baseline yet
No successful-repair baseline yet
No successful-repair baseline yet
No successful-repair baseline yet

Tip: enter only stages you actually observed. For boards that never reach a later stage, leave that stage blank rather than entering a guessed value.

V4.4 Board Knowledge

Previous Solved Cases

Historical cases are diagnostic references only. Confirm readings on the board in front of you before replacing parts.

Live match: Mark a bench signal FAIL to check previous solved cases for 820-01814.

No structured solved-repair knowledge has been collected for this board yet. New V4.4 solved cases will build it automatically.

V4.5 · SIMILAR BOARD / PLATFORM MATCHING

Reference Boards

Reference only: The boards below share one or more stored platform attributes with this motherboard. Their voltages, component locations, designators, sequence details and repair findings are not automatically treated as facts for the current board. Verify against the current board schematic, boardview and measurements before use.

Reference-board matches are discovery aids only. Missing information on this board is deliberately left unknown and is not filled from a similar board.

V4.9 Diagnostic Timeline

Repair Timeline

Bench actions are recorded in sequence for training, QC and future troubleshooting. Signal result changes remain in history even after a failed stage later passes.

    The final solved forum case receives the complete timeline for this bench session. Manual actions should describe what was actually done, not a suspected cause.

    GUIDED BIOS DIAGNOSTICS · V5.1

    BIOS / SPI Flash Diagnostic Record

    Record only measurements observed on this board. The workflow does not assume a flash voltage, logic level or firmware fault from a single reading.

    Original BIOS dump

    The first uploaded original is locked to this diagnostic session and cannot be overwritten by this workflow.

    Repaired BIOS dump

    Stored as a separate attachment. Uploading it never modifies the original dump.

    Final diagnostic decision

    Is the problem solved?

    Complete the applicable checklist and bench rows first. If solved, the completed diagnostic flow is converted into a resolved Repair Forum post automatically.

    V5.0 Repair Case Intelligence

    Board Repair Dashboard

    Aggregate repair patterns for 820-01814 · Rev 1.0.0. Historical patterns are references, not proof of the current fault.

    0Recorded repairs
    0.0%Solved
    Not enough timeline dataAverage diagnosis time
    0Rework cases

    Common symptoms

    No structured data yet.

    Frequently failed rails / signals

    No structured data yet.

    Frequently replaced / repaired ICs

    No structured data yet.

    Common root causes

    No structured data yet.

    Diagnosis time is calculated from V4.9 timeline evidence when available. Only server-recorded board-linked repair cases are counted; unsaved local bench sessions are excluded. Technician performance is never exposed on this board dashboard.

    USB-C / PD DIAGNOSTICS · V5.2

    USB-C Power Delivery Diagnostic Record

    Record observed behavior on this board and adapter. Contract voltage and controller behavior vary by platform; this module does not assume that a higher-voltage PD contract must always be present.

    USB-C port fault checklist

    Check only what was actually inspected. A failed item is a diagnostic clue, not an automatic component diagnosis.

    DISPLAY / NO-DISPLAY DIAGNOSTICS · V5.3

    Internal & External Display Diagnostic Record

    Record board-specific observations. Missing display signals are clues only; expected voltage, polarity and timing must be verified from the schematic, panel specification or known-good board.

    Internal vs external display decision tree

    Complete the checks in order. The guidance below narrows the next area to inspect but does not declare a component faulty.

    Record the internal and external display results to show decision guidance.
    💰

    Estimated repair cost at TCS Pune

    ₹4,000 – ₹15,000

    Final price confirmed after free device inspection. Includes 6-month warranty.

    Get exact quote ↗
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