Original BIOS dump
The first uploaded original is locked to this diagnostic session and cannot be overwritten by this workflow.
TCS Pune
820-02536 – Bench Power & Signal Checklist
Component & Signal Cross-Reference
Search existing schematic component references and nets, then jump to the corresponding bench measurement. References are extracted from the checklist, not independently verified against the schematic.
8 measurement rows · 0 component references · 8 signal labels
BoardView link unavailable for this board/revision. Link a matching BoardView through the existing integration to enable direct viewing.
| Step | Signal / net | Component | Expected | Links |
|---|
Board-specific bench checklist derived from 2 supplied source PDF(s). Source coverage: Limited. Verify exact thresholds, pin numbers and rail tolerances against the source schematic and component datasheets before component replacement or voltage injection.
⚠ 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. Use a short ground spring for high-speed oscilloscope probing.
🛠 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
0 / 5 done
Progress saved in browser.
Schematic-derived bench record
Bench Manual & Source Coverage
Source coverage: Limited. Values and thresholds must still be verified against the exact schematic/datasheet.
Source PDF(s): 820-02536.pdf | MLB 820-02536-09 (Silkscreen).pdf
Board profile
Power & Control Architecture
CPU / SoCApple platform
Table A
Chronological Power Sequence
Follow upstream to downstream. A missing later signal may simply be the result of an earlier missing prerequisite.
| # | Stage | Signal / Rail | From -> To | Ref | State | Expected | DMM | Oscilloscope |
|---|---|---|---|---|---|---|---|---|
| 1 | DC Input | Adapter / DC-IN main rail | Adapter/battery input path | Schematic p.23 | Follow chronological sequence | 19-20 V typical for barrel adapters; USB-C depends on PD contract | Measure to ground at input connector/fuse | Flat DC; inspect ripple only if unstable |
| 2 | Battery | Battery positive / system battery rail | Battery connector -> charger/system | Schematic p.23 | Follow chronological sequence | Pack voltage appropriate to cell count and state of charge | DMM DC at battery positive to pack ground | Flat DC; no excessive ripple |
| 3 | EC / SIO | 32.768 kHz RTC / EC clock | Crystal/oscillator -> EC/PCH | Schematic p.40 | Follow chronological sequence | Stable 32.768 kHz where external low-frequency clock is used | DMM not reliable; use scope | Stable low-amplitude sine/square waveform near 32.768 kHz |
| 4 | Memory | DDR VDD / VDDQ | Memory regulator -> DIMM/SoC | Schematic p.3 | Follow chronological sequence | DDR generation-specific rail; verify schematic and memory generation | DMM DC at memory inductor | Flat DC; low ripple |
| 5 | BIOS / SPI | SPI_CLK | PCH/SoC/EC -> SPI flash | Schematic p.23 | Follow chronological sequence | Clock bursts during firmware access | DMM not diagnostic; use scope | High-frequency clock bursts |
| 6 | Display | Backlight enable | EC/PCH/GPU -> panel/backlight | Schematic p.77 | Follow chronological sequence | Active logic level when backlight should turn on | DMM logic level | Clean assertion after panel power |
| 7 | Display | Backlight PWM | EC/PCH/GPU -> backlight driver | Schematic p.9 | Follow chronological sequence | PWM duty cycle controls brightness; amplitude board-specific | DMM may show averaged voltage; scope preferred | PWM waveform with variable duty cycle |
| 8 | USB-C / PD | USB-C VBUS | USB-C port -> system power path | Schematic p.28 | Follow chronological sequence | 5 V default; 9/15/20 V or other profiles after valid PD contract | DMM DC | Flat negotiated DC; scope for transients only |
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 / 8 checked
| Checked | # | Signal / Rail | Measured | Observed Waveform / Logic | Result | Failure Isolation Hint | Technician Notes |
|---|---|---|---|---|---|---|---|
| 1 | Adapter / DC-IN main railSchematic p.23 | No rail: inspect adapter, jack, fuse, protection MOSFETsAdditional readings | Technician evidence | ||||
| 2 | Battery positive / system battery railSchematic p.23 | Abnormal: verify pack, connector, BATFET and charger pathAdditional readings | Technician evidence | ||||
| 3 | 32.768 kHz RTC / EC clockSchematic p.40 | No clock: inspect crystal, load capacitors, supply and oscillator pinsAdditional readings | Technician evidence | ||||
| 4 | DDR VDD / VDDQSchematic p.3 | Missing: check enable from S4/S3 logic and resistance to groundAdditional readings | Technician evidence | ||||
| 5 | SPI_CLKSchematic p.23 | CS toggles but no clock: inspect controller/bus; no bus activity: trace sequence firstAdditional readings | Technician evidence | ||||
| 6 | Backlight enableSchematic p.77 | Missing: lid/Hall state, graphics sequence, panel detection or firmwareAdditional readings | Technician evidence | ||||
| 7 | Backlight PWMSchematic p.9 | Enable present but no PWM: brightness/graphics/EC control path issueAdditional readings | Technician evidence | ||||
| 8 | USB-C VBUSSchematic p.28 | Stuck at 5 V/no VBUS: inspect CC negotiation, PD controller and power-path FETsAdditional readings | Technician evidence |
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 820-02536.
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.
No sufficiently identified reference boards yet.
Matching becomes available when published board records contain exact charger IC, EC/SIO, CPU model, CPU VR controller or Platform/ODM metadata.
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.
Repaired BIOS dump
Stored as a separate attachment. Uploading it never modifies the original dump.
V6.4 · Repair Case Compare
820-02536 - Compare Solved Cases
Select two or more solved cases from this board. Comparison is for diagnostic reference only; different revisions can behave differently.
At least two solved cases are needed before a comparison can be created for this board.
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.
Repair QC & Final VerificationRequired before solved publication
Every item must be PASS, or N/A with a reason. Any FAIL reopens the repair and blocks the solved forum post.
This report uses the QC selections currently on this page. It does not mark the repair solved or modify existing reports.
V5.0 Repair Case Intelligence
Board Repair Dashboard
Aggregate repair patterns for 820-02536. 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.
820-02536 Diagnostic Patterns
Patterns are derived only from structured solved-case evidence for this board. Select a known failed signal below, or mark a bench row FAIL to open its matching history automatically.
No structured solved cases exist for this board yet. V6.9 will build patterns automatically as solved repairs are recorded.
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.
Next Measurement Assistant
Enter the actual reading and select PASS or FAIL in the bench table. The assistant follows the 820-02536 power sequence and V6.9 solved-case patterns to suggest what to measure next.
WAITING FOR READINGComplete a bench measurement
As you record actual readings, the next recommended test will appear here.
Next measurement—
Expected—
Power state—
Component / path—
Diagnostic aid: recommendations are based on checklist order and recorded repair history. Verify the exact board revision, measurement method and power state. A suggested test is not a declaration that a component is faulty.
BIOS / EC / ME Knowledge
Board-specific firmware reference for 820-02536. Verify board revision, flash voltage/capacity, EC/ME requirements and checksum before programming.
Known-good files
No V7.3 known-good file is stored for this exact board/revision.
Dump history
No V5.1 BIOS diagnostic dumps recorded for this board yet.
Verified repair references
No BIOS/EC/ME solved-case reference has been identified for this exact board yet.
Safety: Compatibility is evidence, not permission to flash. Preserve the original dump and verify voltage, capacity, EC/ME region requirements, board revision and SHA-256.