[Epic 4G General] tidris769:
Recently bought a used epic 4g. It's running FROYO.EC05, unrooted afaik.

This phone won't show up as a mass storage device on my ubuntu 10.10 laptop. Same problem on a desktop PC running ubuntu 11.04.

USB debugging is turned off in the phone. After connecting the phone to the laptop, the phone asks me to select USB mode, and I choose mass storage. Then the 'USB connected' screen with the green android shows up, and I click 'Connect USB storage' there. I click OK on the warning pop-up, then the green android turns yellow and the screen reports 'USB storage in use'. All of that seems normal to me. However on the laptop side the phone doesn't show up as a disk drive.

I use a brand new samsung usb cable purchased specifically for this phone. The usb cable connects directly to the laptop, and I have tried different usb ports on the laptop. I believe the cable is not defective because my other phone (optimus v) shows up as a mass storage device on the laptop just fine with this brand new cable.

I know the laptop is seeing the epic on the usb bus. The epic shows up when I use the lsusb command, and I see syslog usb messages whenever the epic is connected to the laptop. Here is the lsusb info for the epic:

Bus 005 Device 009: ID 04e8:6640 Samsung Electronics Co., Ltd Usb Modem Enumerator
Device Descriptor:
bLength 18
bDescriptorType 1
bcdUSB 1.10
bDeviceClass 2 Communications
bDeviceSubClass 0
bDeviceProtocol 0
bMaxPacketSize0 64
idVendor 0x04e8 Samsung Electronics Co., Ltd
idProduct 0x6640 Usb Modem Enumerator
bcdDevice 0.00
iManufacturer 1 SAMSUNG Electronics Co.,Ltd.
iProduct 2 SAMSUNG CDMA Technologies
iSerial 0
bNumConfigurations 1
Configuration Descriptor:
bLength 9
bDescriptorType 2
wTotalLength 90
bNumInterfaces 3
bConfigurationValue 1
iConfiguration 0
bmAttributes 0xa0
(Bus Powered)
Remote Wakeup
MaxPower 500mA
Interface Descriptor:
bLength 9
bDescriptorType 4
bInterfaceNumber 0
bAlternateSetting 0
bNumEndpoints 1
bInterfaceClass 2 Communications
bInterfaceSubClass 2 Abstract (modem)
bInterfaceProtocol 1 AT-commands (v.25ter)
iInterface 0
CDC Header:
bcdCDC 1.09
CDC Call Management:
bmCapabilities 0x03
call management
use DataInterface
bDataInterface 1
CDC ACM:
bmCapabilities 0x0f
connection notifications
sends break
line coding and serial state
get/set/clear comm features
CDC Union:
bMasterInterface 0
bSlaveInterface 1
Endpoint Descriptor:
bLength 7
bDescriptorType 5
bEndpointAddress 0x81 EP 1 IN
bmAttributes 3
Transfer Type Interrupt
Synch Type None
Usage Type Data
wMaxPacketSize 0x0010 1x 16 bytes
bInterval 32
Interface Descriptor:
bLength 9
bDescriptorType 4
bInterfaceNumber 1
bAlternateSetting 0
bNumEndpoints 2
bInterfaceClass 10 CDC Data
bInterfaceSubClass 0 Unused
bInterfaceProtocol 0
iInterface 3 Data Interface
Endpoint Descriptor:
bLength 7
bDescriptorType 5
bEndpointAddress 0x82 EP 2 IN
bmAttributes 2
Transfer Type Bulk
Synch Type None
Usage Type Data
wMaxPacketSize 0x0040 1x 64 bytes
bInterval 0
Endpoint Descriptor:
bLength 7
bDescriptorType 5
bEndpointAddress 0x02 EP 2 OUT
bmAttributes 2
Transfer Type Bulk
Synch Type None
Usage Type Data
wMaxPacketSize 0x0040 1x 64 bytes
bInterval 0
Interface Descriptor:
bLength 9
bDescriptorType 4
bInterfaceNumber 2
bAlternateSetting 0
bNumEndpoints 2
bInterfaceClass 255 Vendor Specific Class
bInterfaceSubClass 0
bInterfaceProtocol 0
iInterface 0
Endpoint Descriptor:
bLength 7
bDescriptorType 5
bEndpointAddress 0x84 EP 4 IN
bmAttributes 2
Transfer Type Bulk
Synch Type None
Usage Type Data
wMaxPacketSize 0x0040 1x 64 bytes
bInterval 0
Endpoint Descriptor:
bLength 7
bDescriptorType 5
bEndpointAddress 0x04 EP 4 OUT
bmAttributes 2
Transfer Type Bulk
Synch Type None
Usage Type Data
wMaxPacketSize 0x0040 1x 64 bytes
bInterval 0
Device Status: 0x0000
(Bus Powered)

That shows the epic is being recognized as a CDMA modem instead of a mass storage device. By comparison, my optimus v is definitely seen as a mass storage device:

Bus 002 Device 011: ID 1004:61a6 LG Electronics, Inc.
Device Descriptor:
bLength 18
bDescriptorType 1
bcdUSB 2.00
bDeviceClass 239 Miscellaneous Device
bDeviceSubClass 2 ?
bDeviceProtocol 1 Interface Association
bMaxPacketSize0 64
idVendor 0x1004 LG Electronics, Inc.
idProduct 0x61a6
bcdDevice 1.00
iManufacturer 3 LG Electronics Inc.
iProduct 2 LG Android USB Device
iSerial 1 xxxxxxxxxxx
bNumConfigurations 1
Configuration Descriptor:
bLength 9
bDescriptorType 2
wTotalLength 55
bNumInterfaces 2
bConfigurationValue 1
iConfiguration 0
bmAttributes 0xa0
(Bus Powered)
Remote Wakeup
MaxPower 400mA
Interface Descriptor:
bLength 9
bDescriptorType 4
bInterfaceNumber 0
bAlternateSetting 0
bNumEndpoints 2
bInterfaceClass 8 Mass Storage
bInterfaceSubClass 6 SCSI
bInterfaceProtocol 80 Bulk (Zip)
iInterface 0
Endpoint Descriptor:
bLength 7
bDescriptorType 5
bEndpointAddress 0x83 EP 3 IN
bmAttributes 2
Transfer Type Bulk
Synch Type None
Usage Type Data
wMaxPacketSize 0x0200 1x 512 bytes
bInterval 0
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 0
Interface Descriptor:
bLength 9
bDescriptorType 4
bInterfaceNumber 1
bAlternateSetting 0
bNumEndpoints 2
bInterfaceClass 255 Vendor Specific Class
bInterfaceSubClass 66
bInterfaceProtocol 1
iInterface 0
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 0
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 0
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: 0x0000
(Bus Powered)

So hopefully someone knows how to fix this problem with the epic? By the way, adb in the laptop can't see the epic when USB debugging is turned on, but it sees the optimus v, in case that matters.