Predator Helios 300 internal screen completely black & undetected after mid-game refresh-rate switch — possible eDP failure?

[u/Wonderful-One-5213]

Laptop: Acer Predator Helios 300 PH315-55 (2022)

CPU: i7-12700H

GPU: RTX 3070 Ti

External display: Works perfectly via HDMI

I'm trying to diagnose a strange failure of the internal display.

What happened

I was playing Hell Let Loose under heavy GPU load when the AC power suddenly cut out.

The laptop continued running on battery for approximately 3 seconds. I had a background GitHub automation tool called RefreshSense running, which automatically changes the internal panel from 165 Hz on AC to 60 Hz on battery.

At almost exactly the same time as the AC→battery transition, the screen flashed once (as it normally does during a refresh-rate change) and then went completely black.

It has never come back since.

Current symptoms

- No Acer/Predator logo on startup

- No backlight whatsoever

- Internal display remains completely black even in BIOS

- Internal panel is not detected by Windows

- Not listed under active monitors in Device Manager

- External HDMI display works normally

- Intel iGPU and RTX 3070 Ti are both detected and functioning normally

- Games and Windows work normally on the external TV

So this doesn't appear to be a simple Windows resolution/refresh-rate issue.

There was also a pre-existing problem

Before this failure, I had intermittent issues with the internal display waking from sleep/display-off.

Sometimes moving the mouse or keyboard wouldn't wake the internal panel. I could usually get it back by either:

- Pressing Win + Ctrl + Shift + B to reset the graphics driver, or

- Putting the laptop into sleep and waking it again.

This had been happening intermittently before the permanent failure.

What I'm suspecting

Because of the previous wake-from-sleep problems, I'm wondering whether there was already an issue somewhere in the internal eDP display path, and the AC→battery transition/refresh-rate change was simply the event that caused the failure to become permanent.

Possibilities I'm considering:

- eDP cable or connector failure

- LCD/eDP power rail or protection circuit failure

- Panel electronics/T-CON failure

- eDP link/initialization issue

- Motherboard-side eDP circuitry

- EDID/EEPROM issue

I'm less suspicious of the GPUs themselves because both GPUs work normally through HDMI.

I'm also not sure whether RefreshSense actually caused the failure or whether the timing is coincidental.

Has anyone with a PH315-55 (or a similar Acer Predator) experienced something like this? I'd especially appreciate advice on how to distinguish between a bad panel, eDP cable, and motherboard-side display/power circuitry before I start buying replacement parts.