Hi,

We have deployed over 100 S7-1200 systems at various client locations  over the last 3-4 years and are continuously facing the indication LED's failure problem. Within 6-months of operation, the IO LED indication on CPU's and SM go bad. It causes immense problems in diagnostics, as the input sensors and inputs/outputs are working but the LED is not lighting up, which results in confusion during maintenance of machines. And its not only the IO LED's that go bad, even the CPU RUN/ERROR/Maintenance/PROFINET TX/RX LED's go out, and there is no indication remaining on CPU. Is there any solution to this? Has anyone else faced such problems?

Kindly advice. Attached is picture of a system that recently we had to replace because of this problem. Except for the LED's all hardware is functioning only LED's are problematic.

Regards,

Anas

www.pakplc.com

Dear Sir,

We are using Meanwell Power Supply NES-100-24 for Powering PLC, DI, Sensors, and DQ. With fuses inline at Power input of PLC, and IO Modules. Operating temperature < 45degC with forced air cooling. Also the Outputs are not driving any loads other than relays with free wheeling diode protection.

Regards,

Anas

Hi cnmautomation,

I have seen that someone has posted the same issue as you: S7-1200 & it's digital I/O Modules LEDs Fail (Fused) 

Are you colleagues?

If that is so: I recommend that only one of you both asks the problem in the forum/ solve the problem together.

Best regards,

Noodles