I bought Acer asipre 4250. It have built-in SD card reader. But it is not working. Nothing show in /media or fdisk but something in dmesg.

dmesg:

new high-speed USB device number 3 using ehci_hcd
[  127.396733] scsi5 : usb-storage 2-2:1.0
[  128.526562] scsi 5:0:0:0: Direct-Access     Multiple Card  Reader     1.00 PQ: 0 ANSI: 0
[  128.532512] sd 5:0:0:0: Attached scsi generic sg2 type 0
[  129.008110] ohci_hcd 0000:00:12.0: PCI INT A disabled
[  129.032083] ohci_hcd 0000:00:13.0: PCI INT A disabled
[  129.056411] ohci_hcd 0000:00:16.0: PCI INT A disabled
[  129.338026] sd 5:0:0:0: [sdb] Attached SCSI removable disk
[  129.808328] ohci_hcd 0000:00:14.5: PCI INT C disabled
[  167.728616] usb 2-2: USB disconnect, device number 3
[  169.872284] ehci_hcd 0000:00:13.2: PCI INT B disabled
[  169.872340] ehci_hcd 0000:00:13.2: PME# enabled

fdisk -l:

Disk /dev/sda: 320.1 GB, 320072933376 bytes
255 heads, 63 sectors/track, 38913 cylinders, total 625142448 sectors
Units = sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 4096 bytes
I/O size (minimum/optimal): 4096 bytes / 4096 bytes
Disk identifier: 0x0006bc6d

   Device Boot      Start         End      Blocks   Id  System
/dev/sda1   *        2048    48828415    24413184    7  HPFS/NTFS/exFAT
/dev/sda2        48828416    50829311     1000448   82  Linux swap / Solaris
/dev/sda3        50829312    99657727    24414208   83  Linux
/dev/sda4        99659774   625141759   262740993    5  Extended
Partition 4 does not start on physical sector boundary.
/dev/sda5        99659776   275439615    87889920    7  HPFS/NTFS/exFAT
/dev/sda6       275441664   451221503    87889920    7  HPFS/NTFS/exFAT
/dev/sda7       451223552   625141759    86959104    7  HPFS/NTFS/exFAT

I found another problem just right now. I format last three drives as EXT4 with disk utility. But they are showing as NTFS/exFAT in fdisk. :-(