PapaRayRay
New member
Intake Condition
- Liquid damage (customer spill).
- On bench: most ports negotiated 5 V ~0.30 A, one port showed amp “bouncing” (unstable current).
- Ultrasonic clean (proper dry-out).
→ Behavior changed to boot-then-die loop: negotiates 20 V, fans spin for a few seconds till 2.5 A, hard-off to 0 A (20 V holds), then current ramps again (>3 A peak) but won’t relatch without pressing power or replugging. - Set aside a few days. On revisit: stuck at 5 V ~0.30 A, amp-bouncing port symptom gone.
- Heated the previously suspect CD3217 on that bouncing port.
→ Boot-then-die loop returns (same as #1). That made me suspect that CD3217/BGA. - Replaced the suspect CD3217 (side-correct part).
→ No change: still boot-then-die loop as in #1. Can’t force DFU/Revive even using board DFU pads. - Found a clearly burnt/open 0 Ω link: RA602 (between PPBUS_HS_GPU ↔ PPVIN_GPU_COREREG_VIN).
→ Replaced RA602 with proper 0 Ω jumper. No change to symptoms. - Thermal camera during attempts: only the typical region on the back-side of CPU creeps to ~50 °C; no localized hot spots on SSD, PMU/T2 LDO area, USB-C controllers, or GPU VRM caps/FETs.
- Plug USB-C (known-good charger/cable): negotiates 20 V.
- Press power: fans spin, no chime/no image, a few seconds later 0 A (20 V persists), then amps climb again as if it’ll start, but it won’t restart without another power press or replug.
- SMC reset inconclusive; PRAM reset inconclusive.
- DFU won’t assert (even shorting DFU pads); Configurator on host Mac won’t see it.
- CD3217: replaced the controller on the formerly unstable port (amp-bouncing one). Side-matched. No change.
- RA602 (0 Ω): replaced (PPBUS_HS_GPU → PPVIN_GPU_COREREG_VIN). No change.
