Hi,
I have a couple of questions and things to check:
- When did the issue start?
- How is your network set up? (Do you have a router?)
- What is the IP address of your computer?
- What colour is the LED next to the network connection?
Red LED means its in DHCP mode and gets an IP address from your router, white LED means it has a static IP which could be anything.
If the LED is white you could try switching it to red by (shortly) pressing the button next to it.
The QuadCore should receive an IP address from your router that way. (Connecting it directly won't work that way, it needs a DHCP server when red)
If you hold the button next to the LED for longer than 3 seconds, the QuadCore will reset its static IP address to 192.168.1.10.
This means your computer needs to be in the same IP range, 192.168.1.XXX (replace xxx with a number within the range of 1 - 255, I would recommend staying withing the range of 11-99 just to be sure)
Greetings,
Bootsy