Hello sorry my english. I have APM 2.6 board and 3DR external GPS with compass…but GPS is no working, only red led is still solid, blue led do nothing, not blink , not solid… all is original 3DR products bought 2 weeks ago from unmannedshop UK.
5 to 6 pin cabe is good, I chech it…
where is the problem ??? i try it indoor and outdoor too…
thanx
@chavier,
Yes, if your GPS is working correctly, it will flash the blue led at a 1 Hz rate when it has a 2D - 3D lock. What hemisphere are you in? There are some issues getting a good lock in the Southern Hemisphere.
I had an early uBlox GPS that would not get a lock and it turned out to be a defective antenna amplifier IC. Replacement of the GPS module took care of the problem.
Regards,
TCIII Developer
Am from slovakia…
I think the problem will be with the gps modul… 
send to UK…
Have you tried the unit outside?? They can take upto 15 minutes with a clear view of the sky to sort themselves out.