Machine: MacBook Pro 14" M3 Max, A2992 / Mac15,10, board 820-02918, macOS 26.6.2.
History: low drop. Worked normally for ~1 day, then intermittent (one reboot brought it back), now permanent, also after 30 min powered off.
Symptom: no image on the internal panel. Mini-LED local dimming still works: zones light up following the content, so I see a very low-res blurry glow of the desktop. Brightness keys change it. External display perfect, screenshots correct.
Done so far:
Questions:
History: low drop. Worked normally for ~1 day, then intermittent (one reboot brought it back), now permanent, also after 30 min powered off.
Symptom: no image on the internal panel. Mini-LED local dimming still works: zones light up following the content, so I see a very low-res blurry glow of the desktop. Brightness keys change it. External display perfect, screenshots correct.
Done so far:
- Lid angle / pressing the bezel: no change
- Reseated eDP and backlight flexes: no change
- 3.8 V panel rail present at the MLB eDP connector (unloaded, flex disconnected); no short to ground on the display side.
- Logs: no DCP/IOMFB errors or panics, DCP power state normal, brightness commanded normally. Only change: IOMFB: panel charge parity violation value jumped ~100× at fault onset (0x3F9D60 → 0xF9xxxxx) and stays there
- IORegistry names the panel chain AppleParadeDP835TCONI2CTps65177
- Heat on lower bezel: no change
Questions:
- Has anyone measured the LCD bias rails (AVDD/VGH/VGL/VCOM) on the panel-side TCON board of A2442/A2779/A2918/A2992? Test points or typical values?
- Is the bias IC really a TPS65177 (Vin 8.6–14.7 V per datasheet)? With a 3.8 V panel rail there must be a pre-boost. Which part?
- Can the TCON board be reached by removing only the bottom bezel, or does the LCD bottom edge have to be lifted?
- Does anyone know what “panel charge parity violation” counts?