Deep in the back room of "Northside Electronics," an old oscilloscope sat next to a dented soldering station. This was the domain of Mira, a board-level repair technician known for resurrecting devices others called e-waste. On her bench lay a high-end laptop from nearly a decade ago. The owner's complaint was scribbled on a sticky note: "Dead. No power. Lights flicker once."
The ammeter jumped: 0.000A → 0.015A (standby) → 0.850A (power on). The fan spun. The screen glowed. ldb-2 mb 11232-1 schematic
Without a healthy PC403, the 5V rail would ripple. The EC would see the instability and shut down in less than 20 milliseconds—hence the "lights flicker once" symptom. Deep in the back room of "Northside Electronics,"
Mira injected 1V at 2A into the main power rail using her thermal camera. She watched the screen. The 3V/5V standby area glowed faintly—not the main charging IC, not the CPU VRM. A single, 2mm x 1mm component, , was radiating a tiny orange dot of heat at 85°C. The owner's complaint was scribbled on a sticky note: "Dead
The "ghost" was exorcised.
Using her multimeter in resistance mode, she probed the drain of PQ301. Short to ground. The problem was downstream.