Chip no longer accessible after first successful connection and flash attempt

Chip no longer accessible after first successful connection and flash attempthttps://devzone.nordicsemi.com/f/nordic-q-a/128655/chip-no-longer-accessible-after-first-successful-connection-and-flash-attemptI'm having trouble with an MDBT42T-P192K (nRF52805) module and would appreciate any suggestions. This is the sequence of events: I assembled my custom PCB and connected it to a J-Link programmer. Initially, everything appeared to work. nRF Connecten-USTelligent Community 13Tue, 07 Jul 2026 15:53:46 GMTRE: Chip no longer accessible after first successful connection and flash attempthttps://devzone.nordicsemi.com/thread/568873?ContentTypeID=1Tue, 07 Jul 2026 15:53:46 GMT137ad170-7792-4731-bb38-c0d22fbe4515:dc40e7ee-a1c6-4122-a548-f690bb562ffeDenDanne<p>Just to add some information.<br />I am probing SWCLK and SWIO pins on MDBT with oscilloscope.</p> <p><img style="max-height:240px;max-width:320px;" src="https://devzone.nordicsemi.com/resized-image/__size/640x480/__key/communityserver-discussions-components-files/4/pastedimage1783439592449v2.png" alt=" " /></p> <p>As you can see, there are definately data transmission (but could be just one way of course).</p><div style="clear:both;"></div>