Wan Ports of fortigate 80c Error

[aungzawtun]

Dears,

i have the problem with fortigate 80.Please help me.

My 8C wan ports( wan1 ,wan2 ) don't work normally (can't detect with ISP wan Link) . They are always down. They never UP when they are connected with ISP wan link.But They always UP when they are connected with any other switches (Dlink or cisco or tplink etc) and they can perform their activities.If i connect wan ports to ISP link directly ,they go down and show in active. Other Lan ports and DMZ port work normally.

i already fireware upgrade to 5.2.5 and downgrade to 5.0 .But it is not working.

How should i do. Please help me