S7-300: CPU does not have any lights

Wayne.Lawton1979

Hi,

Yes, the CPU is protected internally by a surface mount fuse which needs to be desoldered and replaced with the same type already fitted, this is usually an OMF125 4A. see attached link

https://www.mouser.co.uk/Circuit-Protection/Fuses/Surface-Mount-Fuses/OMF-125-Series/Datasheets/_/N-ba8gu?P=1yyrzas

 Hi there, I am using 6ES7317-2AK14-0AB0 on my stenter Machine. Suddenly the machine stopped. And the cpu don't have any lights. I checked the supply 24vdc was ok. Then after 12/13 hours machine was without power. After that when we power on again the cpu had light and it was good condition but its configuration got default. Same things happens after 5 days again.

Can anyone help me with this issue please ??

?

If the fuse fried how it can on after some hours??

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Split from No light On s7 300.

Hello For My Job,

If during operation all the lights on the S7-300 go out or the power supply is not working properly or the PLC has an internal fault, I would first try to change the power supply and if not, it will be necessary to repair the S7-300.