This is a "brick." Try unplugging the power for 10 minutes, then holding the power button for 30 seconds while plugging it back in. If this fails, the firmware was likely incompatible with your hardware version.
If you have obtained the correct .bin or .img update file from your seller or a trusted forum, follow these steps: yg300 projector software update
Go to Settings > Info/About to see your current firmware version. This is a "brick
The Ultimate Guide to the YG300 Projector Software Update The YG300 (often called the Lumos or Pico projector) is a favorite for budget home theaters. However, because it’s a generic "white-label" device produced by various manufacturers, finding a reliable software update can be tricky. The Ultimate Guide to the YG300 Projector Software
If you updated to fix a codec issue and it didn't work, it’s likely a hardware limitation. The YG300 does not support 4K or certain Dolby Audio codecs. The best "update" for this is actually a , which handles the software processing for the projector. Projector Won't Turn On After Update
Insert the USB into the projector while it is turned off . The Update Sequence: Turn on the projector. Navigate to Settings > System Update > USB Update .