MacBook Pro M5 + KVM + LG TV: Clamshell mode fix

gistfile0.txt

# Clamshell mode fix: MacBook Pro M5 + KVM MINIX K1 + LG TV

## Setup
- **Mac**: MacBook Pro M5 Pro, macOS 26.5
- **KVM**: MINIX K1 USB-C (no EDID emulation)
- **Display**: LG TV connected via HDMI

---

## Problems & Fixes

### 1. Black screen when closing the lid
- **Cause**: LG TV blocks high-resolution signals without the right setting
- **Fix**: TV → Settings → Picture → HDMI Settings → enable **HDMI Ultra HD Deep Colour** on the port being used

### 2. macOS not detecting lid closure
- **Diagnose**: Run `pmset -g log | tail -40` and look for `com.apple.powermanagement.lidopen`
- **Cause**: KVM has no EDID emulation — macOS doesn't see a stable external display
- **Note**: Clamshell still activates with MINIX K1 despite the log entry

### 3. Optimal resolution/refresh rate
| Setting | Result |
|---|---|
| 4K@120Hz | Black screen (too much bandwidth through KVM) |
| 4K@60Hz | Works but text is too small on TV |
| **1080p@60Hz scaling:on** | ✅ Stable and comfortable |

---

## Key tool: displayplacer

```bash
# Install
brew install jakehilborn/jakehilborn/displayplacer

# List display and available modes
displayplacer list

# Apply 1080p@60Hz (stable config)
displayplacer "id:<YOUR_DISPLAY_ID> res:1920x1080 hz:60 color_depth:8 enabled:true scaling:on origin:(0,0) degree:0"
```

---

## Quick diagnostics

```bash
# Check what displays macOS detects
system_profiler SPDisplaysDataType

# Check sleep/wake and lid events
pmset -g log | tail -40
```

> If you see `Television: Yes` → enable HDMI Ultra HD Deep Colour on the TV.  
> If you see `lidopen` in pmset → make sure the charger is connected and nothing is between the lid and keyboard.