RBM33G + R11-LTE6 on 6.48/7.4 - LTE interface randomly missing

Hi there, couldn’t find anything useful on the net, so I thought I’d share my extreme frustration and ask for help.

I’ve got myself an RBM33G with R11-LTE6 mPCIe module which I’ve upgraded to 7.4 and it’s not a smooth experience as I am used to from Mikrotik.

The LTE interface barely gets recognized. I’ve tried boot init delays, USB power resets, USB jumper combinations, and nothing works. Averagely, in out of 10 attempts, the LTE interface gets recognized and modem is shown in USB devices in only 2-3 cases, which is pretty bad. I am also worried about stability issues when the LTE interface would be in use.

Anybody got similar experience?

Maybe not related but did you also upgrade that modem to latest version ?
Should be V034 right now.

Yep, the modem’s firmware is the latest version. Will try swapping to different mPCIe slot later today and also downgrade to factory version to see if it helps.

It’s a pity it’s not that polished, I thought when it’s all from Mikrotik (board + modem) it should just work flawlessly. Obviously it’s not the case.

What I’ve also noticed is that resetting the modem (i.e. fiddling with LTE settings, disabling/enabling the interface, etc.) takes much more time than I’m used to with my Chateau LTE12 - there it’s almost instant action.

Strange but seems that it is R11 related … different vendor and “the show go on without hickups”
http://forum.mikrotik.com/t/v7-4-stable-is-released/159556/136

So you suggest downgrading?

Downgrading didn’t help. Behaves basically the same. Maybe I have not mentioned that I am powering RBM33G via 24V passive POE injector on a CAT6A STP cable (fully compliant with RBM33G specs). I will probably stick to different modem vendor.

Wondering if R11-LTE6 consumes more than 1A of current during startup and that could be the problem it just doesn’t boot. Because I’ve just realized my POE injector is 24V/1A only.

Well, according to PCIe specs, the peak power consumption on mPCIe slot could be as high as 2.7A (3.3V rail) or 0.5A (1.5V rail).

R11-LTE6 specs say that the max power consumption is 5W, so I speculate it can take as much as 1.5A alone.

I will try to power RBM33G with some more juice to see if it helps.

Okay, so the current solution for me is to stick to different modem vendor. Even juicy 3A external power supply didn’t help and after several reboots, power downs/ups, etc. the R11-LTE6 never appeared as LTE interface - strangely, my subjective feeling is that it was much better, although random in nature, with my 24V/1A PoE injector. Now Mikrotik should go figure out what’s going on here - I’ve sent them a support ticket, just for curiosity sake.

Do not know … MT ROS and MT devices shouldn’t “hurt” each other. It’s crazy that other brands are recognized but their own not.

Returned the modem and got myself an Quectel EP06 instead. Seems to be working fine so far.