MDS 600 Amber alert

[euls]

i have MDS 600

and it show amber alert in the GSI LED

i checked the fan, the power supply and the temprture 

all work fine

but the amber alert not go

the  7-segment display show: 

error# 01

which mean : SES overall warning 

i replace fans one by one and wait 30 seconds between each replace 

but also not help

please advise us