my projector says 'no signal' but everything is plugged in and my fire tv stick works on the tv.

Diagnosis

The "No Signal" error on the Optoma UHD50X when using a Fire TV Stick typically stems from an HDCP (High-bandwidth Digital Content Protection) handshake failure or a resolution mismatch. Because the UHD50X is a high-performance 4K projector, it expects a specific signal timing. If the Fire Stick was previously configured for a different television, it may be outputting a resolution or a refresh rate (such as 60Hz on a non-compatible port) that the projector cannot synchronize with during the initial boot sequence. Furthermore, the UHD50X has multiple HDMI ports with varying capabilities. If the Fire Stick is plugged into a port that is expecting a different signal type, or if the device is not receiving sufficient amperage from the projector's USB service port, the Fire Stick may enter a "low power" state. In this state, the device appears to be powered on (the LED may be lit), but it fails to send a video signal to the projector, resulting in the persistent "No Signal" screen despite the cables being physically secure.

How to Fix It

1. Ensure the Fire TV Stick is plugged into HDMI 1, as this port typically offers the most stable handshake for external streaming dongles.
2. Do not rely on the projector's USB port for power. Plug the Fire Stick's power adapter directly into a dedicated AC wall outlet using the original 5V power brick. This prevents the "under-voltage" signal drop that causes "No Signal" errors.
3. Power on the Optoma UHD50X and allow it to fully warm up for 60 seconds before plugging in the Fire Stick.
4. Press the Source button on the remote or the projector chassis. Carefully cycle through the options (HDMI 1, HDMI 2, VGA) and pause on HDMI 1 for at least 10 seconds to allow the 4K handshake to complete.
5. If the screen remains black, perform a "Hard Sync": Unplug the HDMI cable from the back of the projector, turn the projector off, unplug the power cord from the wall for 30 seconds, plug the HDMI cable back in, and then restore power.

If That Didn't Work

• Force a Resolution Reset: Since you cannot see the menu, you may need to plug the Fire Stick back into the TV where it works. Go to Settings > Display > Resolution and change it from "Auto" to "1080p 60Hz." Once saved, move it back to the UHD50X. The projector will often lock onto a 1080p signal more easily, allowing you to then scale up to 4K within the projector's settings.
• Swap the HDMI Cable/Extender: If you are using the small HDMI flexible extender that came with the Fire Stick, remove it and plug the stick directly into the port. These short extenders are notorious for causing signal attenuation and HDCP failures on 4K projectors.
• Disable HDMI Link/CEC: In the Optoma system menu, navigate to the Setup or HDMI settings and disable "HDMI Link" (CEC). Sometimes the Fire Stick attempts to take control of the projector's power state, which creates a loop that prevents the video signal from triggering.
• Test with a Different Source: Plug a laptop or a gaming console into the same HDMI port. If the laptop displays an image, the issue is specifically the Fire Stick's output settings. If the laptop also says "No Signal," the HDMI port on the projector may be damaged or the cable is faulty.

Heads Up

• Avoid using long HDMI cables (over 15 feet) without an active booster or a fiber optic HDMI cable; the UHD50X requires a very strong signal to maintain 4K resolution.
• Keep the projector's firmware updated via the USB service port to ensure compatibility with newer versions of the Fire OS.
• Ensure the projector is not in "Eco Mode" when first connecting a 4K source, as some users report slower handshake times in low-power modes.
• Always shut down the projector using the remote and allow the fans to stop completely before unplugging the device to prevent motherboard voltage spikes.