When the red/source LED is off but the green sensor LED is on, Genie lists missing or bad wiring to the source as one possible problem and also notes that power may have been interrupted. Check the source-side wiring and reapply power before assuming both sensors need replacement.
Read Genie Safe-T-Beam red and green LEDs together
What is each Safe-T-Beam eye reporting at the same time?
Record both LED states before choosing a blink-code branch.
Genie identifies the red LED unit as the source/transmitter and the green LED unit as the receiver. A blink count is not enough by itself: several diagnostic branches change depending on whether the other LED is steady, off or also abnormal.
This exact manufacturer signal can feed the following diagnostic family. Keep the original code or LED pattern when troubleshooting.
What you are likely to notice
- The red/source Safe-T-Beam LED is off
- The green receiver LED remains on
- The door may refuse normal downward travel because the safety system is not in its normal solid-red/solid-green state
Check these in order
1. Verify which eye is the source
Genie identifies the red LED unit as the transmitter/source and the green LED unit as the receiver. Make sure you are reading the correct side before diagnosing wiring.
2. Inspect wiring to the source
Check the source-side terminal connection and visible low-voltage wire for looseness, cuts or pinches. Genie specifically lists missing/bad source wiring for this LED pair.
3. Reapply opener power
Because Genie also lists interrupted power for this state, remove and reapply power using the normal opener power connection if it is safe to do so, then observe the LEDs again.
4. Re-test only after both LEDs are steady
Normal Safe-T-Beam operation is indicated by solid red and solid green LEDs. If the source remains dark, move to model-specific support rather than bypassing the system.
One dark source is different from both sensors dark
Genie's chart distinguishes red/source off with green on from the both-off state. With green still on, the published branches focus on wiring to the source or a power interruption. That is why the exact LED pair matters.
Identify the red transmitter before touching wiring. If someone has swapped physical positions or you are looking at a legacy sensor style, use the product documentation to confirm which unit is which.
Restore the normal pair, then test
Normal Safe-T-Beam operation is solid red plus solid green. Once both return, perform the reversal test rather than assuming the system is healthy from indicator lights alone.
If the red source will not return after normal power is restored and accessible wiring is secure, use Genie support. Do not jump to a universal sensor replacement unless the exact opener compatibility is verified.
Red OFF + green ON points away from simple beam alignment
Genie's Safe-T-Beam table lists source/red OFF with green ON as a source-side power or wiring condition: wiring to the source may be missing/bad, or power may have been interrupted. That is different from the common two-red-blink pattern used for obstruction/alignment. Preserve this state before swapping sensor positions or aiming the brackets.
Start by confirming that the condition is stable and that the opener has normal power. Then check the visible source-side wiring and connections. Genie also lists removing and reapplying power as a step for this state. If the red source remains off while green remains on after the basic power/wiring checks, keep the diagnosis on the source circuit rather than drifting into unrelated travel, force or remote settings.
- Red/source OFF + green ON: source wiring/power-interruption branch.
- Red blinking + green ON: use the blink-count table instead.
- Both OFF: move to the powerhead/wiring branch for the whole Safe-T-Beam circuit.
If red remains off while green stays on, record whether cycling opener power changes either LED and whether the source-side wire is visibly intact at both accessible ends. Do not erase that state by swapping parts first. A stable OFF/ON pair is far more useful to Genie support or a technician than a later report that simply says the door would not close.
Stop DIY troubleshooting when…
- Source wiring is damaged beyond an accessible repair
- The opener terminal block is damaged
- The red source remains off after normal power is restored
- Any attempt would require bypassing Safe-T-Beam
Garage door springs, cables and a falling/unbalanced door can store or release dangerous force. Those are door-system problems, not just opener settings.
Common questions
What does red off and green on mean on Genie Safe-T-Beam?
Genie lists missing/bad wiring to the source or a recent power interruption.
Which Genie sensor is the transmitter?
Genie identifies the red LED unit as the transmitter/source and the green LED unit as the receiver.
Should both lights be solid during normal operation?
Yes. Genie says solid red and solid green indicate normal operation.
Manufacturer sources used
These links are the factual baseline for the diagnostic claims above. Model-specific manuals can supersede general guidance.