| Symptom | Likely Faulty Chip/Area | Diode Mode Reading | |---------|------------------------|---------------------| | No light, no fan | 19V DC input circuit, first MOSFETs | Short between Drain-Source | | Lights on, but no POST | BIOS chip corruption or PCH | Check CS# pin activity on BIOS | | Turns off after 2 seconds | Missing power good (PG) signal from a regulator | Verify ALL_SYS_PWRGD voltage (3.3V) | | Shorted to ground on main rail | MLCC capacitor or MOSFET | Look for resistance <10Ω |
The system is fully powered, including the CPU and GPU. Key Components: laptop motherboard chip level repair guide pdf
: Temperature-controlled iron with fine tips for precise bridge repairs. Diagnostics Digital Multimeter | Symptom | Likely Faulty Chip/Area | Diode