I recently bought a non-working Asus Zenbook Pro Duo OLED UX8402ZA that was listed for parts only. The seller mentioned that it had no display output but that the charging lights worked.
When the laptop arrived (without a charger and SSD), I connected a charger and confirmed with a multimeter that it was charging the battery. However, when I tried to power it on, only the backlight of the secondary display came on. There was no image, and it didn’t boot into the BIOS.
I decided to try flashing a new BIOS, but since I didn’t want to desolder...