Dear all, 

We have an unmanaged switch Scalance X005 6GK5005-0BA00-1AA3. When I connect HMI and PLC by profinet cable using Connector 6GK1901-1BB11-2AA0, sometimes the connections not good.

I tried to use the same cable and connector with a normal switch (not Industrial Switch of Siemens), the connection is good.  So the cable and connector is ok. The problem maybe from Switch Scalance. We faced this problem 2,3 times, in diferrent projects using Scalance X005. Can anybody help me to know what is the problem?

Thank you.

hi Tunando,

see the Manual, chapter 6 Maintenance and Trobleshooting:

Fuses

The SCALANCE X005 and SCALANCE X005TS IE switches have a resettable fuse / PTC. If the fuse triggers (all LEDs are off despite correctly applied power supply), the device should be disconnected from the power supply for approximately 30 minutes before turning it on again.

Device defective

If a fault develops, please send the device to your SIEMENS service center for repair. Repairs on-site are not possible.

https://support.industry.siemens.com/cs/de/de/view/22261701/en

regards,