HP EliteBook 745 G5 - No Display After Shutdown, Only Works After Deep Drain

[Devon2929]

Hello HP Community,

I have an HP EliteBook 745 G5 with a very strange issue. I have already tried multiple troubleshooting steps, but I need expert advice before proceeding with repairs.

🔍 Issue Description:

• If I shut down my laptop, the display does not turn on when I power it back on.

• No HP logo, no backlight, just a black screen.

• Keyboard (Caps Lock) works, and HDMI output works fine, but the laptop screen stays black.

• The only way to get the display back is to perform a deep drain (remove battery, long press power, then wait).

• After the deep drain, the HP logo appears, but the laptop auto-restarts once before booting normally.

🛠️ Troubleshooting I Have Tried:

✅ External HDMI Works → GPU & OS are fine.

✅ Flashlight Test → No faint image, meaning not just a backlight issue.

✅ Reseated Display Cable (Motherboard Side) → No effect.

✅ Reset BIOS to Defaults (F10 BIOS Setup) → No effect.

✅ Safe Mode Boot → No effect.

✅ Startup Repair → Failed.

✅ Reinstalled Windows 10 (Fresh Install) → No effect.

✅ Updated BIOS to the Latest Version from HP → No effect.

⚠️ Additional Clues:

• The issue only started after downgrading from Windows 11 back to Windows 10.

• After downgrading, I played Dota 2, then shut down normally. The next day, the laptop would no longer display.

• Before the issue happened, I saw a red ❌ X error message before the laptop shut down, but I didn’t read it.

• I recently replaced the keyboard, and I accidentally turned on the laptop with the CMOS battery disconnected.

❓ My Questions for the HP Experts:

1️⃣ Could this be an Embedded Controller (EC) firmware issue causing the display to fail after shutdown?

2️⃣ Is there a way to reflash/reset the EC using software without opening the laptop?

3️⃣ Could this be a power delivery issue (bad Power IC or capacitor) affecting display initialization?

4️⃣ Since HDMI works, could this be a failing LCD cable inside the hinge that was not checked yet?

Any advice would be greatly appreciated before I proceed with hardware repairs! Thanks in advance!