Troubleshooting:
LED D11: Heart Beat - This light will flash on and off to indicator power. If this light is off, no power (either AC or DC) is being sent to the circuit board.
LED D12: Low Battery Indicator
When the batteries become weak, the gate will begin to run noticeably slower. (NOTE: Batteries should only be check when you are sure they have had adequate time to fully charge.) Turn off the AC power and run gate for 5 to 10 cycles while observing low battery indicator LED D12. If LED D12 come ON, batteries are too weak to function properly. If LED D12 does not light, then voltage should be checked as they still may be near failure. Correct voltage is approximately 25.5VDC. (NOTE: If LED D12 does light, gate will open to conserve batteries in this test or in a real power loss, even if mode switch 8 on S2 is off.) Return of AC power will clear low battery indicator. Correct charge voltage is 27.5VDC with batteries not connected (adjustment is at R63).
LED D14: AC Power Indicator - AC power source has been interrupted if this light is NOT on. Check for power source. Check 15amp AC fuse (F3). Older boards may have a red 10amp fuse. It is safe to replace this fuse with a blue 15amp fuse.