I have two RB951Ui-2HnD routers and two usb modems huawei E3531. When i use the router number one both modems work fine as well as the router. When i use the second router the usbs dont connect to the internet (the flashligth turns on and off every 3 sec). I have the latest card firmware, i power restart the usb port and i measure the volt of the router(everything looks fine).


What can it be????

Maybe try to swap the power supplies on the Mikrotiks or do a factory reset on the Mikrotik that does not work and try again.

done that already didnt work.
Any other suggestions?

I had the same problem, but with RB2011 router. Official Mikrotik support told me that it is problem with usb power. They advised to contact local distributor to request RMA warranty repair or replacement. So you need to contact Mikrotik support, get ticket number and go to your local distributor or company where you've bought the router.

Thougth so. Thanjs for your help.