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Download files

File Type Access
820-01949_schematic_1.brd BoardView (.brd) Open in browser / download
📄 820-01949_schematic_2.pdf PDF Schematic Open in browser / download
📄 820-01949_schematic_3.pdf PDF Schematic Open in browser / download
BoardView files (.brd) — open with OpenBoardView (free, Windows/Linux) for interactive component location. PDF schematics open in any PDF viewer.

Board overview

MacBook Pro 16" (2019), board number 820-01949. Intel Core i7/i9 9th generation (Coffee Lake-H) with AMD Radeon Pro 5300M or 5500M discrete GPU (Navi architecture). The Apple T2 security chip (T8012) handles SMC, storage encryption and boot security. Includes 3 files: 1 BoardView (.brd) and 2 PDF schematics.

CPU / GPU
Intel Core i7/i9 9th gen (Coffee Lake-H)
PMU / Charger
ISL9239C charger, T8012 (T2)
Connectivity
CD3217 × 4
Schematic ref.
820-01949

Power rails reference

Rails listed in measurement priority order — start at the top. Each rail must be present before the next can be generated.

Rail name Voltage Notes & fault hints
PPBUS_G3H 12.6 V Primary bus. From ISL9239 (adapter) or battery. Measure first — must be present for any boot.
PP3V3_G3H 3.3 V Always-on 3.3 V derived from PPBUS_G3H. Present whenever a battery is connected.
PP5V_S5 5.0 V S5 5V standby. SMC-generated. Absent = SMC fault or enable missing.
PP3V3_S5 3.3 V S5 3.3 V standby. First programmable rail from SMC.
SMC_BC_ACOK 3.3 V Adapter OK signal from ISL9239 to SMC. Absence = charger not detected.
PP5V_S0 5.0 V Active-state 5 V. Requires SMC S0 state. Feeds USB-C and peripherals.
PP3V3_S0 3.3 V Active 3.3 V. Used by PCIe, NVMe, peripheral ICs.
PP1V8_S0 1.8 V Active 1.8 V. CPU I/O, LP8557 backlight, display logic.

Common failure zones

Most likely failures first. Each entry gives a symptom and the immediate diagnostic action.

No charging — no SMC_BC_ACOK
ISL9239C charger IC or surrounding passives. Check VBUS on USB-C, then CD3217 CC communication.
AMD GPU artefacts / no display
Radeon Pro 5300M/5500M failure. Measure AVDD, MVDD GPU rails. Reflow rarely successful — reballing required.
No power — PPBUS_G3H absent
Check battery voltage directly. If battery OK, ISL9239 or upstream fuse. Measure fuse continuity near barrel area.
T2 related boot failure
T8012 T2 handles NVMe encryption. No boot without T2. Check T2 power rails first (PP3V3_G3H to T2).
Backlight failure
LP8557 boost IC or PPBUS to backlight. Measure BLEN, CABC signals from GPU. Check backlight fuse.