how to upgrade the R7100LG - Nighthawk 4G LTE Modem Router to new firmware

Hi,

Does anyone know How I can upgrade the R7100LG - Nighthawk 4G LTE Modem Router when the upgrade to the new firmware failed using the browser?

What I did:

I opened the control panel of my router in a browser. On top of the site it stated there was a new firmware available so I clicked that button to start the upgrade. After 25 minutes there was no response, so I rebooted the router. Now I have a flashing / blinking power led with indicate I have a faulty firmware. I can ping my router but I am unable to open the control panel using a browser.

actions taken:

I downloaded both the new 1.0.0.30 and the previouw version 1.0.0.28 to install the firmware manually according this website: Reinstall the firmware on a router without the setup CD recovery tool . I can set the times it wil retry at a 20 times but it all failed stating: Unable to get response from the server. retry (20/20)...

question: 

Does anyone know if here is any other way to upgrade the firmware other than the two methodes mentioned above? 

nice to know: the router was purchaged on jan. 9. 2017. so I am just out of the complementary support (90 days....)