Hello,
There are 2 red leds. One is a Smd led on the voltage regulator pcb (red pcb). That light should be always on. If it is not on, a power supply problem is present and you need to return the unit so that I can send a new one. The other red led is the one that signals output being sent on P5. That led together with the 4 green leds will flash once after power.
If the voltage regulator is OK please try a factory reset pressing and holding the Boot button. When you press the button all leds will go On and after 2 or 3 seconds they go Off. When they go Off you can release the button.
I suggest you answer this question writing to my email luis@vela-navega.com. If possible include a photo of the pcb just for me to be sure that you have a red voltage regulator.
Regards, Luis