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<?xml-stylesheet type="text/xsl" href="https://devzone.nordicsemi.com/cfs-file/__key/system/syndication/rss.xsl" media="screen"?><rss version="2.0" xmlns:dc="http://purl.org/dc/elements/1.1/" xmlns:slash="http://purl.org/rss/1.0/modules/slash/" xmlns:wfw="http://wellformedweb.org/CommentAPI/" xmlns:atom="http://www.w3.org/2005/Atom"><channel><title>nrf52840 - Not working with J3 and LED1,2,3, and 4 are blinking</title><link>https://devzone.nordicsemi.com/f/nordic-q-a/99648/nrf52840---not-working-with-j3-and-led1-2-3-and-4-are-blinking</link><description>We are trying to use nrf52840DK for the Openthread FTU unit. While we are able to flash the Hex file, upon changing the USB cable to J3, it&amp;#39;s not getting recognized under the USB connection (ttyACM???), and all 4 LEDs (LED1,2,3 and 4) start blinking continuously</description><dc:language>en-US</dc:language><generator>Telligent Community 13</generator><lastBuildDate>Fri, 19 May 2023 11:06:23 GMT</lastBuildDate><atom:link rel="self" type="application/rss+xml" href="https://devzone.nordicsemi.com/f/nordic-q-a/99648/nrf52840---not-working-with-j3-and-led1-2-3-and-4-are-blinking" /><item><title>RE: nrf52840 - Not working with J3 and LED1,2,3, and 4 are blinking</title><link>https://devzone.nordicsemi.com/thread/426227?ContentTypeID=1</link><pubDate>Fri, 19 May 2023 11:06:23 GMT</pubDate><guid isPermaLink="false">137ad170-7792-4731-bb38-c0d22fbe4515:280dcb72-80f0-4e6a-848c-a53ad402cae5</guid><dc:creator>ArunRuchir</dc:creator><description>&lt;p&gt;Thanks, Naeem,&lt;/p&gt;
&lt;p&gt;&lt;/p&gt;
&lt;p&gt;Have sought replacement of DK board. Hope this problem will not come in new hardware.&amp;nbsp;&lt;/p&gt;
&lt;p&gt;Thanks for your help.&amp;nbsp;&lt;/p&gt;
&lt;p&gt;Regards&lt;/p&gt;
&lt;p&gt;Arun&lt;/p&gt;&lt;div style="clear:both;"&gt;&lt;/div&gt;</description></item><item><title>RE: nrf52840 - Not working with J3 and LED1,2,3, and 4 are blinking</title><link>https://devzone.nordicsemi.com/thread/426172?ContentTypeID=1</link><pubDate>Thu, 18 May 2023 18:33:25 GMT</pubDate><guid isPermaLink="false">137ad170-7792-4731-bb38-c0d22fbe4515:da83aef6-218c-4089-a00f-d90104098d72</guid><dc:creator>Naeem Maroof</dc:creator><description>&lt;p&gt;Hi Arun,&lt;/p&gt;
&lt;p&gt;&lt;/p&gt;
&lt;p&gt;Thank you for sending more information.&lt;/p&gt;
&lt;p&gt;&lt;/p&gt;
&lt;p&gt;As per your case where you have 2 DKs, and 1 is working perfectly fine while the other is showing these symptoms.&lt;/p&gt;
&lt;p&gt;&lt;/p&gt;
&lt;p&gt;I am assuming that you are powering both DKs the same way, and the configuration of the switches (SW9 and SW6) are also the same.&lt;/p&gt;
&lt;p&gt;&lt;/p&gt;
&lt;p&gt;In such a case, this could be problem in the DK. However, may I suggest to directly connect the DK to the computer without USB hub and see if it works.&lt;/p&gt;
&lt;p&gt;&lt;/p&gt;
&lt;p&gt;BR,&lt;/p&gt;
&lt;p&gt;Naeem&lt;/p&gt;&lt;div style="clear:both;"&gt;&lt;/div&gt;</description></item><item><title>RE: nrf52840 - Not working with J3 and LED1,2,3, and 4 are blinking</title><link>https://devzone.nordicsemi.com/thread/425434?ContentTypeID=1</link><pubDate>Sat, 13 May 2023 05:30:29 GMT</pubDate><guid isPermaLink="false">137ad170-7792-4731-bb38-c0d22fbe4515:6485dce7-09f4-4f25-ac7e-343e2667778b</guid><dc:creator>ArunRuchir</dc:creator><description>&lt;p&gt;Dear Naeem,&lt;/p&gt;
&lt;p&gt;&lt;/p&gt;
&lt;p&gt;Thanks for your response. To your questions:&lt;/p&gt;
&lt;p&gt;1) Yes. Same cable. Just shifted the connection from J2 to J3.&amp;nbsp;&lt;/p&gt;
&lt;p&gt;2) No. Same cable.&amp;nbsp;&lt;/p&gt;
&lt;p&gt;SW9 - is on USB Power&lt;/p&gt;
&lt;p&gt;SW6 is on Default&lt;/p&gt;
&lt;p&gt;We have 2 DK boards (newly purchased) and both have identical switches and other positions. One is working fine and this one is having the above-mentioned issues. This one is not getting recognized on serial tty* also. A video enclosed for the issue.&amp;nbsp;&lt;/p&gt;
&lt;p&gt;Please suggest a solution or help with the replacement of this defective board.&amp;nbsp;&lt;/p&gt;
&lt;p&gt;Thanks.&amp;nbsp;&amp;nbsp;&lt;/p&gt;
&lt;p&gt;&lt;a href="https://devzone.nordicsemi.com/cfs-file/__key/communityserver-discussions-components-files/4/nrf52840DK-issue.mp4"&gt;devzone.nordicsemi.com/.../nrf52840DK-issue.mp4&lt;/a&gt;&lt;/p&gt;&lt;div style="clear:both;"&gt;&lt;/div&gt;</description></item><item><title>RE: nrf52840 - Not working with J3 and LED1,2,3, and 4 are blinking</title><link>https://devzone.nordicsemi.com/thread/425297?ContentTypeID=1</link><pubDate>Fri, 12 May 2023 11:06:24 GMT</pubDate><guid isPermaLink="false">137ad170-7792-4731-bb38-c0d22fbe4515:2c072ef7-d135-43f2-987b-0c8274f89263</guid><dc:creator>Naeem Maroof</dc:creator><description>&lt;p&gt;Hi&lt;/p&gt;
&lt;p&gt;Thank you for contacting DevZone at NordicSemi.&lt;/p&gt;
&lt;p&gt;1) Is it the same usb cable that you have used for programming, and now you are connecting from J2 to J3?&lt;/p&gt;
&lt;p&gt;2) Or you are using another cable for J3?&lt;/p&gt;
&lt;p&gt;Apparently, from your description, I would suggest to check the state of SW9 and SW6.&lt;/p&gt;
&lt;p&gt;To power through USB via J3, SW9 should be on &lt;strong&gt;USB_Source &lt;/strong&gt;side&lt;/p&gt;
&lt;p&gt;If you want to only power the SoC, then switch SW6 to &lt;strong&gt;nRF_Only&lt;/strong&gt;&lt;/p&gt;
&lt;p&gt;Please check the power sources and operating modes in the DK user guide:&amp;nbsp;&lt;a href="https://infocenter.nordicsemi.com/pdf/nRF52840_DK_User_Guide_20201203.pdf"&gt;nRF52840_DK_User_Guide&lt;/a&gt;&lt;/p&gt;
&lt;p&gt;Regards,&lt;/p&gt;
&lt;p&gt;Naeem&lt;/p&gt;&lt;div style="clear:both;"&gt;&lt;/div&gt;</description></item></channel></rss>