SIMATIC S7-400 / S7-400H / S7-400F /FH

Problem with s7-400(416-3dp)

Thread Starter: Amir2003   Started: 11/11/2011 7:48 AM   Replies: 3

  11/11/2011, 7:48 AM

Amir2003 Joined 8/5/2008 Last visit: 3/22/2012 Posts: 2 Rating:  (0)	(0)  Since about 2 weeks ago one of our cpu's crushed and all front led's start blinking therefor we replaced it with new one and now another one failed! with same problem! can any one help me why these problem happen for our system and give me more information to prevent these problem?! thx&sorry for my bad english
	Top

  11/11/2011, 10:47 AM

Marcjan Joined 4/22/2010 Last visit: 6/18/2013 Posts: 3307 Rating:  (300)	(1)  Hello, 2 cpu's dead in a short time can be a lot of things: 1. Cpu really defect, check power supply, memorycard if there and possible EMC problems. 2. Cpu is o.k. but there is a problem with the backplane. So check the cpu in another rack with another powersupply unit and have a good look at grounding/ shielding of cables and other equipment in the cabinet. Regards, Marcjan Problem solved? Please let us know! Please no technical questions by PM, use the forum!
	Top
	Thank you for this post from: Amir2003

  11/11/2011, 4:20 PM

Amir2003 Joined 8/5/2008 Last visit: 3/22/2012 Posts: 2 Rating:  (0)

(0)  Dear sir thank for u'r attention I've check defect CPU in another Rack with new power supply It works some times! ( another time all LED's blink! or INTF&EXTF blinking (with out stop LED) or all front LED's are ON) if I update firmware what will happen to CPU's(work or not) and about grounding and schielding I'm sure about them(check it before) and main powers are comming from UPS also i must remember I've install new cpu's on old backplaine but work correctly without error and also these 2 cpu's are for two defrent department but in a one electrical room(rawmill&kiln-CEMENT INDUSTRY-) thank's

Top

  11/17/2011, 8:43 AM

Aret Joined 10/31/2005 Last visit: 6/13/2013 Posts: 2107 Rating:  (200)	(0)        Check your old (replaced) CPU with new backplane. I guess problem is in rack. Also can check current backplane for broken pins - improper installing of module can cause pins to be bound - can be a problem. MMC can also be a problem, as Marсофт mentioned - can you run PLC without it (as you have UPS it seems you wont have problems with power, so removing MMC can be regarded as normal).
	Top