boardrepair.me · Schematic reference
MacBook Pro A1989
Files are provided for diagnostic and repair purposes only. Use
/schematic 820-01700 / 820-00850 in the Telegram bot to download automatically.
Download files
| File | Type | Access |
|---|---|---|
| ⊞ a1989_schematic_1.brd | BoardView (.brd) | Open in browser / download |
| 📄 a1989_schematic_2.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 13" Touch Bar (2018–2019), board number 820-01700. Intel 8th generation Whiskey Lake (Core i5/i7). Fully USB-C design with 4 × CD3217 controllers. Apple T2 chip (T8012) handles SMC, SSD encryption, and boot security. ISL9239C fast-charge controller. Includes BoardView (.brd) and PDF schematic.
CPU / GPU
Intel Core i5/i7 8th gen (Whiskey Lake)
PMU / Charger
ISL9239C (charger), T8012 (T2 SMC)
Connectivity
CD3217 × 4
Schematic ref.
820-01700 / 820-00850
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 | Main bus rail from ISL9239 or battery. First measurement point. No PPBUS = no boot, no charging possible. |
PP3V3_G3H |
3.3 V | Always-on 3.3 V derived from PPBUS. Powers T2 and standby logic even when 'off'. |
SMC_BC_ACOK |
3.3 V | Adapter detected signal. Generated by ISL9239, received by T2/SMC. Critical for initiating charge sequence. |
PP3V3_S5 |
3.3 V | T2-generated standby rail. Absent = T2 not alive. Check PP3V3_G3H to T2 input. |
PP5V_S5 |
5.0 V | Standby 5 V. Powers USB-C VCONN when machine is sleeping. |
PP5V_S0 |
5.0 V | Active 5 V. Requires T2 S0 enable. Feeds Touch Bar, Touch ID, USB-C. |
PP3V3_S0 |
3.3 V | Active 3.3 V. Gated by T2. PCIe, NVMe, peripherals. |
PP1V8_S0 |
1.8 V | Active 1.8 V. CPU I/O, LP8557 backlight logic, display controller. |
Common failure zones
Most likely failures first. Each entry gives a symptom and the immediate diagnostic action.
No charging on any USB-C port
Measure PPBUS_G3H first. If present, test SMC_BC_ACOK with known-good cable+charger. Dead ISL9239 or T2 power domain fault.
No charging on one or two USB-C ports
CD3217 controller on affected side. Check CC lines. Very common after liquid ingress near left port cluster.
No power — PPBUS present, dead
T2 not initialising PP3V3_S5. Check PP3V3_G3H delivery to T2. Check T2 reset line. Liquid damage under T2 area.
Touch Bar not working
Touch Bar has separate power rails and serial communication. Check PPVDD_TOUCHBAR. Also check SPI/I2C bus from T2 to Touch Bar.
Backlight failure
LP8557 boost IC. Measure BLEN signal, PPBUS_G3H into LP8557. Check F9700-equivalent backlight fuse on A1989.