# Have i bricked my Sierra MC7710?

**URL:** <https://forum.sierrawireless.com/t/have-i-bricked-my-sierra-mc7710/8971>\
**Category:** MC/EM Series\
**Created:** [December 30, 2016, 9:37am UTC](https://forum.sierrawireless.com/t/have-i-bricked-my-sierra-mc7710/8971 "2016-12-30T09:37:45Z")\
**Posts on this page:** 3\
**Page:** 1

<div class="post-metadata">

**Author:** ![bovo30](https://avatars.discourse-cdn.com/v4/letter/b/74df32/32.png) [@bovo30](https://forum.sierrawireless.com/u/bovo30)\
**Post date:** [December 30, 2016, 9:37am UTC](https://forum.sierrawireless.com/t/have-i-bricked-my-sierra-mc7710/8971/1 "2016-12-30T09:37:45Z")

</div>

Hi everyone,

I have a problem with my Sierra MC7710. During the upgrading process I have wrote the wrong AT command, changing the idProduct from 68A3 to 68E2 instead 68A2. It was necessary to change from “Direct IP” to “QMI Mode”.

```auto
AT!UDPID=68E2
```

Now, I cannot found the device in /dev/ttyU\* to change the idProduct via AT command, but the modem is recognized by the SO:  
Here there is the lsusb command:

```auto
Bus 001 Device 001: ID 1d6b:0002 Linux Foundation 2.0 root hub
Bus 002 Device 001: ID 1d6b:0001 Linux Foundation 1.1 root hub
Bus 003 Device 001: ID 1d6b:0001 Linux Foundation 1.1 root hub
Bus 004 Device 001: ID 1d6b:0001 Linux Foundation 1.1 root hub
Bus 005 Device 001: ID 1d6b:0001 Linux Foundation 1.1 root hub
Bus 001 Device 003: ID 1199:68e2 Sierra Wireless, Inc. 
Bus 004 Device 002: ID 413c:2003 Dell Computer Corp. Keyboard
Bus 001 Device 004: ID 0951:1665 Kingston Technology
```

and here the output of lsusb -D /dev/bus/usb/001/003:

```auto
Device: ID 1199:68e2 Sierra Wireless, Inc. 
Device Descriptor:
  bLength 18
  bDescriptorType 1
  bcdUSB 2.00
  bDeviceClass 0 (Defined at Interface level)
  bDeviceSubClass 0 
  bDeviceProtocol 0 
  bMaxPacketSize0 64
  idVendor 0x1199 Sierra Wireless, Inc.
  idProduct 0x68e2 
  bcdDevice 0.06
  iManufacturer 3 Sierra Wireless, Incorporated
  iProduct 2 MC7710
  iSerial 4 358178043178963
  bNumConfigurations 1
  Configuration Descriptor:
    bLength 9
    bDescriptorType 2
    wTotalLength 115
    bNumInterfaces 4
    bConfigurationValue 1
    iConfiguration 1 Sierra Configuration
    bmAttributes 0xe0
      Self Powered
      Remote Wakeup
    MaxPower 0mA
    Interface Descriptor:
      bLength 9
      bDescriptorType 4
      bInterfaceNumber 0
      bAlternateSetting 0
      bNumEndpoints 2
      bInterfaceClass 255 Vendor Specific Class
      bInterfaceSubClass 255 Vendor Specific Subclass
      bInterfaceProtocol 255 Vendor Specific Protocol
      iInterface 0 
      Endpoint Descriptor:
        bLength 7
        bDescriptorType 5
        bEndpointAddress 0x81 EP 1 IN
        bmAttributes 2
          Transfer Type Bulk
          Synch Type None
          Usage Type Data
        wMaxPacketSize 0x0200 1x 512 bytes
        bInterval 32
      Endpoint Descriptor:
        bLength 7
        bDescriptorType 5
        bEndpointAddress 0x01 EP 1 OUT
        bmAttributes 2
          Transfer Type Bulk
          Synch Type None
          Usage Type Data
        wMaxPacketSize 0x0200 1x 512 bytes
        bInterval 32
    Interface Descriptor:
      bLength 9
      bDescriptorType 4
      bInterfaceNumber 2
      bAlternateSetting 0
      bNumEndpoints 2
      bInterfaceClass 255 Vendor Specific Class
      bInterfaceSubClass 255 Vendor Specific Subclass
      bInterfaceProtocol 255 Vendor Specific Protocol
      iInterface 0 
      Endpoint Descriptor:
        bLength 7
        bDescriptorType 5
        bEndpointAddress 0x82 EP 2 IN
        bmAttributes 2
          Transfer Type Bulk
          Synch Type None
          Usage Type Data
        wMaxPacketSize 0x0200 1x 512 bytes
        bInterval 32
      Endpoint Descriptor:
        bLength 7
        bDescriptorType 5
        bEndpointAddress 0x02 EP 2 OUT
        bmAttributes 2
          Transfer Type Bulk
          Synch Type None
          Usage Type Data
        wMaxPacketSize 0x0200 1x 512 bytes
        bInterval 32
    Interface Descriptor:
      bLength 9
      bDescriptorType 4
      bInterfaceNumber 3
      bAlternateSetting 0
      bNumEndpoints 3
      bInterfaceClass 255 Vendor Specific Class
      bInterfaceSubClass 255 Vendor Specific Subclass
      bInterfaceProtocol 255 Vendor Specific Protocol
      iInterface 0 
      Endpoint Descriptor:
        bLength 7
        bDescriptorType 5
        bEndpointAddress 0x83 EP 3 IN
        bmAttributes 3
          Transfer Type Interrupt
          Synch Type None
          Usage Type Data
        wMaxPacketSize 0x0040 1x 64 bytes
        bInterval 5
      Endpoint Descriptor:
        bLength 7
        bDescriptorType 5
        bEndpointAddress 0x84 EP 4 IN
        bmAttributes 2
          Transfer Type Bulk
          Synch Type None
          Usage Type Data
        wMaxPacketSize 0x0200 1x 512 bytes
        bInterval 32
      Endpoint Descriptor:
        bLength 7
        bDescriptorType 5
        bEndpointAddress 0x03 EP 3 OUT
        bmAttributes 2
          Transfer Type Bulk
          Synch Type None
          Usage Type Data
        wMaxPacketSize 0x0200 1x 512 bytes
        bInterval 32
    Interface Descriptor:
      bLength 9
      bDescriptorType 4
      bInterfaceNumber 8
      bAlternateSetting 0
      bNumEndpoints 3
      bInterfaceClass 255 Vendor Specific Class
      bInterfaceSubClass 255 Vendor Specific Subclass
      bInterfaceProtocol 255 Vendor Specific Protocol
      iInterface 0 
      Endpoint Descriptor:
        bLength 7
        bDescriptorType 5
        bEndpointAddress 0x85 EP 5 IN
        bmAttributes 3
          Transfer Type Interrupt
          Synch Type None
          Usage Type Data
        wMaxPacketSize 0x0040 1x 64 bytes
        bInterval 5
      Endpoint Descriptor:
        bLength 7
        bDescriptorType 5
        bEndpointAddress 0x86 EP 6 IN
        bmAttributes 2
          Transfer Type Bulk
          Synch Type None
          Usage Type Data
        wMaxPacketSize 0x0200 1x 512 bytes
        bInterval 32
      Endpoint Descriptor:
        bLength 7
        bDescriptorType 5
        bEndpointAddress 0x04 EP 4 OUT
        bmAttributes 2
          Transfer Type Bulk
          Synch Type None
          Usage Type Data
        wMaxPacketSize 0x0200 1x 512 bytes
        bInterval 32
Device Qualifier (for other device speed):
  bLength 10
  bDescriptorType 6
  bcdUSB 2.00
  bDeviceClass 0 (Defined at Interface level)
  bDeviceSubClass 0 
  bDeviceProtocol 0 
  bMaxPacketSize0 64
  bNumConfigurations 1
Device Status: 0x0001
  Self Powered
```

How can I resolve the problem. Or I have to buy a new one ☹ ?  
Thanks.

---

<div class="post-metadata">

**Author:** ![dl5162](https://sea1.discourse-cdn.com/flex025/user_avatar/forum.sierrawireless.com/dl5162/32/2169_2.png) [@dl5162](https://forum.sierrawireless.com/u/dl5162)\
**Post date:** [December 30, 2016, 2:33pm UTC](https://forum.sierrawireless.com/t/have-i-bricked-my-sierra-mc7710/8971/2 "2016-12-30T14:33:08Z")

</div>

Looks like it is in QMI mode and working. Your problem is most likely simply that there are no drivers recognizing that device ID. Try doing

```auto
modprobe option
echo 1199 68e2 >/sys/bus/usb-serial/drivers/option1/new_id
```

You should then get a few /dev/ttyUSBx devices. Find the AT one and use it to change the PID back to what you want.

(Note that the “option” driver isn’t really the correct serial driver for this modem. But it is very forgiving, which is why I tend to recommend it for this kind of temporary fixes.)

---

<div class="post-metadata">

**Author:** ![bovo30](https://avatars.discourse-cdn.com/v4/letter/b/74df32/32.png) [@bovo30](https://forum.sierrawireless.com/u/bovo30)\
**Post date:** [January 3, 2017, 8:43am UTC](https://forum.sierrawireless.com/t/have-i-bricked-my-sierra-mc7710/8971/3 "2017-01-03T08:43:33Z")

</div>

It worked!

Great, thank you very much.