https://community.nxp.com/t5/Layerscape/Fuse-blowing-external-power-supply/m-p/1319746#M8668 <P>Hello all,</P><P>&nbsp;</P><P>so I'm using Grapeboard which is based on LS1012A. I'm trying to run secure boot and for that purpose I should blow fuses. In order to do that 1.8V should be supplied to SFP_PROG pad. Due to Grapeboard design an external power supply (PS) is needed. This means both PSs, main and external, should have common ground. However, due to unexpected design of barrel PS jack (when plugged disconnects 2 ground points of jack) I ended up in situation using 2 PSs without common ground. Both PS are AC/DC converters.One operatin at 12V and other at 1.8V (with current limitation to 1A). Photo below.</P><P><span class="lia-inline-image-display-wrapper lia-image-align-inline" image-alt="OzTheWizard_1-1628262244527.png" style="width: 400px;"><img src="https://community.nxp.com/t5/image/serverpage/image-id/152147i3E8CAD7F6B9AF04B/image-size/medium?v=v2&amp;px=400" role="button" title="OzTheWizard_1-1628262244527.png" alt="OzTheWizard_1-1628262244527.png" /></span></P><P>Did I potentially damage the board?&nbsp;</P> Fri, 06 Aug 2021 15:05:45 GMT OzTheWizard 2021-08-06T15:05:45Z https://community.nxp.com/t5/Layerscape/Fuse-blowing-external-power-supply/m-p/1319746#M8668 <P>Hello all,</P><P>&nbsp;</P><P>so I'm using Grapeboard which is based on LS1012A. I'm trying to run secure boot and for that purpose I should blow fuses. In order to do that 1.8V should be supplied to SFP_PROG pad. Due to Grapeboard design an external power supply (PS) is needed. This means both PSs, main and external, should have common ground. However, due to unexpected design of barrel PS jack (when plugged disconnects 2 ground points of jack) I ended up in situation using 2 PSs without common ground. Both PS are AC/DC converters.One operatin at 12V and other at 1.8V (with current limitation to 1A). Photo below.</P><P><span class="lia-inline-image-display-wrapper lia-image-align-inline" image-alt="OzTheWizard_1-1628262244527.png" style="width: 400px;"><img src="https://community.nxp.com/t5/image/serverpage/image-id/152147i3E8CAD7F6B9AF04B/image-size/medium?v=v2&amp;px=400" role="button" title="OzTheWizard_1-1628262244527.png" alt="OzTheWizard_1-1628262244527.png" /></span></P><P>Did I potentially damage the board?&nbsp;</P> Fri, 06 Aug 2021 15:05:45 GMT https://community.nxp.com/t5/Layerscape/Fuse-blowing-external-power-supply/m-p/1319746#M8668 OzTheWizard 2021-08-06T15:05:45Z https://community.nxp.com/t5/Layerscape/Fuse-blowing-external-power-supply/m-p/1319791#M8671 <P>&gt; Did I potentially damage the board?&nbsp;</P><P>Not necessarily, but cannot be stated for sure.</P> Fri, 06 Aug 2021 18:00:44 GMT https://community.nxp.com/t5/Layerscape/Fuse-blowing-external-power-supply/m-p/1319791#M8671 ufedor 2021-08-06T18:00:44Z