🛠️ MSI GP75 Leopard MS-17E71 – No Display, Deep BIOS/EC Troubleshooting

[macabook]

Hello everyone,

I’m currently working on a dead MSI GP75 Leopard (MS-17E71) motherboard (i7 CPU, NVIDIA GPU) with a no display/no backlight issue initially. After extensive investigation, I’m at a critical stage involving EC firmware, BIOS/ME region interaction, and possible deep corruption. I'm seeking advanced insight from anyone with experience in EC/BIOS sync issues or PCH-level behavior. Here’s a full breakdown:

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🧩 Initial Issue

• Board powers on (fans spin, keyboard lights up and can be adjusted, caps lock led lights), but no display or backlight
• External display (HDMI) shows nothing
• No POST beep, no boot sound
• Screen changes shade slightly on power ON/OFF, so panel receives at least minimal power/signal

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Basic Power Checks

• All power rails to CPU, GPU, PCH confirmed present
• Resistance on coils:
  • CPU: Low (a few ohms, normal)
  • GPU: ~0.5Ω dropping slowly to 0 → verified normal on other working boards
• Injected 0.9V at GPU rail, 2.5A → no shorts, nothing heating up
• Signals present:
  • GPU_ON = 1.8V
  • SYS_PWR_OK = 3.3V
  • PLT_RST# = 3.3V
  • PEX_RST# = ~1.73V (pulled up by 2.2k to 1.8V)
  • GFX_CLKREQ initially 3.3V → drops to 0.02V after startup
• GFX_REFCLK pair measured at ~1.5 MHz, ~0.53V → not sure if it’s ok ?

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Firmware Work So Far (using CH341A and neoprogrammer)

• Flashed BIOS (16MB image from MSI site) → No change
• Also tried a cleaned ME version of BIOS from vinafix→ machine became completely unresponsive
• Reflashed EC firmware separately → recovered initial state
• Then:
  • Reflashing BIOS seems to overwrite EC (even when EC is flashed first)
  • Every time I flash the BIOS, comparing EC dump shows mismatch at end
  • Suggests BIOS contains embedded EC block that's automatically flashed during boot/reset

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EC + BIOS Interaction Observed

• Using HxD hex editor, I confirmed BIOS file contains partial EC firmware blocks
• Not all segments of standalone EC file are present in BIOS
• This raises the possibility of:
  • BIOS containing an incomplete or compressed EC loader/firmware
  • EC auto-update logic triggered on reset
  • Mismatch causing EC corruption or incorrect operation

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New Symptom

• After reflashing BIOS + EC to MSI stock versions:
  • Laptop powers on, then shuts down after ~1 minute
  • PCH gets very hot
  • If cooled (with freeze spray), board stays on longer → seems thermal-triggered

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What is the actual situation

After trying multiple combinations of cleaned ME bios and EC firmware from backup and MSI site nothing is working I can’t even go back to the initial situation by re-flashing backups.

• power sequence is ok until SLP_S5# which is missing
• Checked 32.768 kHz RTC crystal → present and stable

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What I Need Help With

1. Is the EC firmware in the BIOS image complete or partial? there is a hardware reset button that suggests a firmware reset, but from where ? I couldn’t find any other bios chip
2. Is there a documented method to disable EC auto-flash from BIOS?
3. Could EC/BIOS mismatch explain the missing SLP_S5# or PCH overheating?
4. Is there a known good version combo for EC firmware + BIOS for MS-17E71?
5. Has anyone seen a board that powers on but PCH overheats due to EC misbehavior?

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Files Available

• Original 16MB BIOS dump from board (original.bin)
• Official MSI BIOS file (E17E7IMS.10C.bin)
• Official MSI EC firmware (MS-17E71.107.bin)
• Cleaned ME version of BIOS