@Zipper
Problem solved like suggested by you, I simply went to Prefs:Workbench and tick Hidden Devices and ticked the devices to hidden!Many thanks Zipper!
@DrDekker
I don't think it's time to change my mobo for a silly problem like this,anyway when my A1200T would die I have
other 3 A1200 and I could easily change the motherboard.
:eureka: