Page 1 of 1

Possible HW Failure EM7455

Posted: Tue Jul 27, 2021 10:54 am
by ericleslie
I've been running a Sierra Wireless EM7455 in the original The Wireless Haven USB3.0 To NGFF M.2 Key to an RPI4 with OpenWRT successfully for about a year now. I've had intermittent dropouts, but they were usually short and solved with a reboot. The Modem is no longer detected. I've always feared I wasn't powering the setup fully. I was running POE to the RPI and was powering the key with the USB3 and the aux micro-USB, also plugged into a spare port on the RPI4. I understand that is probably not enough power under load.

I was doing some troubleshooting and noticed that the key makes a buzzing sound when I only have the USB3 plugged in. Thinking I may have damaged the key, I just bought the updated Key that has the power upgrades. I'm also powering the RPI and the Key via their own dedicated power supplies now. The issue remains.

This is the dmesg output

Code: Select all

[ 4147.691846] usb 2-2: new SuperSpeed Gen 1 USB device number 9 using xhci_hcd
[ 4147.722689] usb 2-2: config 1 has an invalid interface number: 12 but max is 4
[ 4147.729915] usb 2-2: config 1 has an invalid interface number: 13 but max is 4
[ 4147.737170] usb 2-2: config 1 has an invalid interface number: 13 but max is 4
[ 4147.744416] usb 2-2: config 1 has no interface number 1
[ 4147.749676] usb 2-2: config 1 has no interface number 4
[ 4147.755520] usb 2-2: New USB device found, idVendor=1199, idProduct=9071, bcdDevice= 0.06
[ 4147.763714] usb 2-2: New USB device strings: Mfr=1, Product=2, SerialNumber=0
[ 4147.770852] usb 2-2: Product: EM7455
[ 4147.774431] usb 2-2: Manufacturer: Sierra Wireless, Incorporated
[ 4147.785509] usb 2-2: Enable of device-initiated U1 failed.
[ 4147.791708] usb 2-2: Enable of device-initiated U2 failed.
[ 4147.813046] cdc_mbim 2-2:1.12: cdc-wdm0: USB WDM device
[ 4147.818840] cdc_mbim 2-2:1.12 wwan0: register 'cdc_mbim' at usb-0000:01:00.0-2, CDC MBIM, b2:f0:47:50:04:c4
[ 4147.829320] usb 2-2: Enable of device-initiated U1 failed.
[ 4147.835938] usb 2-2: Enable of device-initiated U2 failed.
[ 4208.622592] usb 2-2: USB disconnect, device number 9
[ 4208.628313] cdc_mbim 2-2:1.12 wwan0: unregister 'cdc_mbim' usb-0000:01:00.0-2, CDC MBIM
mmcli -L does not list any modems.

Is there any other troubleshooting I can do to see if it's actually the modem that's bad?

Thank you!

Re: Possible HW Failure EM7455

Posted: Thu Jul 29, 2021 6:54 am
by Didneywhorl
Plug it into a PC and see if you experience dropouts there as well.