Help identifying the function of these two coils - MSI Delta 15 (MS-15CK1)

[Salvador Pérez]

Hello everyone, I'm troubleshooting an MSI Delta 15 (MS-15CK1) motherboard, and I need help identifying the function of the two coils marked in the attached image. The laptop powers on and responds to the keyboard, but the screen does not turn on-neither the LCD nor the backlight. I've checked the main power rails, and all other coils seem to have the expected voltages:

• 0.91V for the GPU
• 1.7V for VRAM
• 3.3V and 5V rails 1.8V for the BIOS
• 0.9V for the CPU and iGPU 1.2V for the RAM

However, these two coils are not showing any voltage.

Their resistances are:
• First coil: 0.9 ohms
• Second coil: Almost 00.

I have already replaced the three MOSFETs visible in the image with new ones, but the issue remains. Any insight into their function or where to look next would be greatly appreciated.

Thanks in advance!

[kotel studios]

So you say the laptop responds to keyboard strokes, but no display on built in screen? How about external?

[Salvador Pérez]

I've tried connecting a screen via HDMI and USB-C, but I get no image. The system seems to be in BIOS due to the CMOS clear, but I can't reach Windows without a display. I've tried navigating the BIOS blindly, but I can't exit to the OS -though I did manage to restart once.

I've been researching and asking online, and people say that new systems don't output BIOS video through HDMI, only through the integrated GPU. The thing is, the screen seems to have all its voltages (12V, 3.3V, 5V) and some voltage (0.7V) on the lanes of the connector, but on the other side of the coupling capacitors (the side going to the display), I get 0V.

[kotel studios]

I've tried connecting a screen via HDMI and USB-C, but I get no image. The system seems to be in BIOS due to the CMOS clear, but I can't reach Windows without a display. I've tried navigating the BIOS blindly, but I can't exit to the OS -though I did manage to restart once.

I've been researching and asking online, and people say that new systems don't output BIOS video through HDMI, only through the integrated GPU. The thing is, the screen seems to have all its voltages (12V, 3.3V, 5V) and some voltage (0.7V) on the lanes of the connector, but on the other side of the coupling capacitors (the side going to the display), I get 0V.

That would indicate the coupling caps being bad. Recheck them if they are okay.