Eth0 up/network issues

i am currently using BBB-Red board which as industrial grid…
with Debian GNU/Linux 7.8 (wheezy) os and made to boot from SDcard and image date is Debian Image 2015-03-01.

lsb_release -a
No LSB modules are available.
Distributor ID: Debian
Description: Debian GNU/Linux 7.8 (wheezy)
Release: 7.8
Codename: wheezy

i try to power up this bbb with my own carrier card with external power supply, it is (carrier card with external power supply) absolutely working with BBB-balck board and having same OS. if i connect this board to BBB-red board and powered on but eth0 doesn’t came up, but in BBB-black board its working fine…
i tried with dmesg and i found below mesg…

dmesg | grep eth0
[ 5.623106] net eth0: initializing cpsw version 1.12 (0)
[ 5.628425] net eth0: phy found : id is : 0x7c0f1
[ 5.633516] net eth0: phy 4a101000.mdio:03 not found on slave 1
[ 5.665388] IPv6: ADDRCONF(NETDEV_UP): eth0: link is not ready

so there is no ethernet connection up.
The carrier card with external power supply have 4 RS485 with serial digital isolator Si8422…

plz can any one tell what was the issues… even i thought of loading issues but its not…

looks like a hardware issue, could be:

  • improper power sequence (maybe BBB-red powers up too early… I dunno what is bbb red)
  • not enough power delivery/ or sudden power spike