You flip the projector on, the lamp warms up, and the screen just sits there reading "No Signal." The source is powered. The cable is plugged in. Nothing reaches the wall.
This is one of the most common Epson complaints, and it is almost never the projector dying. Nine times out of ten the cause is the input selection, a stale HDMI handshake, or a cable that cannot carry the distance. Work through these in order, because the list is sorted by how often each one turns out to be the real problem.
Check the input first
Epson projectors do not always jump to the active input on their own. Press the Source Search button on the remote, or the Source button on the projector itself, and let it cycle every input. If your streamer is on HDMI1 and the projector is parked on HDMI2, you get "No Signal" even though everything is connected. On the Home Cinema models like the 2350, 880, and 3800, Source Search takes a few seconds to lock, so give it a moment before you decide it failed.
While you are here, confirm the source device is actually sending a picture. A Fire TV Stick or Roku that fell asleep, a cable box on standby, or a laptop that was never told to use the external display all look identical to a dead port. On a Windows laptop, hold the Windows key and press P, then pick Duplicate.
Reseat, then power cycle
HDMI connectors back themselves out of a ceiling-mounted projector over time as the cable weight tugs on them. Unplug both ends, the projector side and the source side, and push them home until they seat firmly. Then power everything down, pull the projector's power cord for a full 30 seconds, and bring it back up. That clears a stuck handshake, which is the single most common reason a setup that worked yesterday fails today.
The long-run problem most people miss
Here is the one that trips up ceiling installs. A passive HDMI cable starts dropping 4K somewhere around 25 feet, and plenty of projector runs are longer than that once you route through the attic. The picture either never appears or flickers in and out. If your run is over roughly 25 feet, you need a fiber optic active HDMI cable, not a longer passive one. Those carry full bandwidth over 50, 75, even 100 feet. A passive 50-footer will never hold a stable 4K link, so do not waste money on one.
Worth knowing while you shop: HDMI cables are rated by speed, not by version. There is no such thing as an "HDMI 2.1 cable." What you want for 4K is an Ultra High Speed cable, certified for 48 Gbps. Buy by the speed rating and ignore the version number on the package.
Handshake and HDCP
If you get a picture on some sources but a stubborn "No Signal" on one specific device, an HDCP copy-protection handshake probably did not complete. Power the projector and that source off together, unplug both, wait 30 seconds, then turn the source on first and the projector second. Order matters more than people expect. If you route through an AV receiver, pull it out of the chain and go straight from source to projector to find out whether the receiver is the weak link.
Epson's HDMI Link, their name for HDMI-CEC, can also grab the wrong input on its own or refuse to hold one. If the input keeps switching, open the menu and turn HDMI Link off to rule it out.
When it is the hardware, not you
If a known-good cable, a confirmed-awake source, and a clean power cycle still get you nothing on every input, the HDMI board inside the projector may have failed. The tell is simple: no source works on any port, even with short cables you have tested elsewhere. That is an Epson service call, not a settings tweak. Epson's projector warranty typically runs two years, so check your purchase date before you pay for a repair, and have the model and serial number ready when you call.
For most people it never gets that far. It is the input, the handshake, or a cable that cannot carry the run, and ten minutes of working down the list in order puts the picture back on the wall.