# External power supply damaged board?

**URL:** <https://discourse.myriadrf.org/t/external-power-supply-damaged-board/1207>\
**Category:** LimeSDR\
**Created:** [9 May 2017 00:07 UTC](https://discourse.myriadrf.org/t/external-power-supply-damaged-board/1207 "2017-05-09T00:07:08Z")\
**Posts on this page:** 1\
**Showing post:** 24

<div class="post-metadata">

**Author:** ![BelmY](https://yyz2.discourse-cdn.com/flex034/user_avatar/discourse.myriadrf.org/belmy/32/843_2.png) [@BelmY](https://discourse.myriadrf.org/u/BelmY)\
**Post date:** [18 May 2017 04:45 UTC](https://discourse.myriadrf.org/t/external-power-supply-damaged-board/1207/24 "2017-05-18T04:45:32Z")

</div>

Hi everybody,  
just to know, is there any relation with the symptoms and problems described in this post?

> [@No lights when powered from EXT power supply](https://discourse.myriadrf.org/t/no-lights-when-powered-from-ext-power-supply/987):
>
> Hi All, Been using my Lime board for a few days - mostly powered by the USB3. RF signals through either of the 3 RF paths are quite weak. I looked at the Quick Test procedures: [https://wiki.myriadrf.org/LimeSDR-USB\_Quick\_Test](https://wiki.myriadrf.org/LimeSDR-USB_Quick_Test) Loopback test with WCDMA has the right profile, but also a few spurs (i have LimeSDR in luftek’s enclosure+ front/rear plates). Having read in a few threads that USB power is not the cleanest one, i switched to 6V EXT power supply. With EXT power supply i do not get an…

Also, if a live connection (while is USB powered) to EXT Supply plug was done, is it possible an spike (if different grounding system is used, current flows balancing), apart from the absolute maximum voltage exceeding, could damage the board (i.e. the more sensitive components in the path)?

Any recommendation to prevent this potential damage risk (i.e. as power up sequencing, power source limitations, no live connection, safe USB removal, etc)?

Cheers  
BelmY

---

_[View the full topic](https://discourse.myriadrf.org/t/external-power-supply-damaged-board/1207)._