11/1/2022 5:25 AM | |
Joined: 12/12/2020 Last visit: 2/1/2024 Posts: 5 Rating:
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Basically, it’s one of the common problems we see on S7 series CPUs. The display remains on connecting. It means the display itself boots up ok and waits for the connection to the internal CPU. The CPU cannot boot up cleanly and is unable to make a connection to the display. So, no hardware information including interface addresses, module identification, etc. cannot be displayed. See the attached photos. Not surprisingly, factory reset or whatsoever cannot be done. So, we need to repair the CPU. It’s not a piece of cake job. We need some degree of circuit knowledge and soldering skills for SMD devices and BGAs. The display boots up normally means internal operation voltages are OK. Only the CPU does not boot up and becomes ready. ------------------------------------------------------------------------------------------ |
Last edited by: vismag1 at: 11/01/2022 05:27:31Last edited by: Jen_Moderator at: 11/02/2022 12:35:19New subject after splitting |
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11/2/2022 2:13 PM | |
Joined: 7/7/2010 Last visit: 8/16/2024 Posts: 15092 Rating:
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Just so I understand correctly, you are saying when these problems happen, you open up the S7-15xx PLC, break apart the various circuit boards, start inspecting for bad solder joints, and once one has been identified, apply proper amount of heat in right manner to repair bad solder joint(s). Reassemble, install in rack, power up and smiles all around when it works. Did I explain correctly? And I see you mention BGAs. You actually discovered bad BGA solder jobs? You really are skilled at microelectronic board level repair in that case. It's so difficult to see underneath those chips once installed.
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science guy |
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8/31/2023 9:32 PM | |
Joined: 3/21/2017 Last visit: 8/10/2024 Posts: 3 Rating:
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Can you tell me where you found the issue, i have 3 1515 processors with this issue |
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