user48175: My Arduino has all of its LEDs on. The Rx, Tx and L LEDs are all on and my computer can’t see it (it's an SMD edition).

user31105: It can have many reasons, but you can try the following:
First time use?

Check if you need to install a special driver for CH340

Environment/Software problems

Try another USB port
Change USB cable
Restart Arduino IDE
Restart computer
Reinstall Arduino IDE

Hardware problems

Test using another Arduino
Test using another computer/laptop
Replace USB cable
The Arduino is (partly) broken, nothing much to do here


48175: <p>My Arduino has all of its LEDs on. The <code>Rx</code>, <code>Tx</code> and <code>L</code> LEDs are all on and my computer can’t see it (it's an SMD edition).</p>
 31105: <p>It can have many reasons, but you can try the following:</p>

<p><strong>First time use?</strong></p>

<ul>
<li>Check if you need to install a special driver for CH340</li>
</ul>

<p><strong>Environment/Software problems</strong></p>

<ul>
<li>Try another USB port</li>
<li>Change USB cable</li>
<li>Restart Arduino IDE</li>
<li>Restart computer</li>
<li>Reinstall Arduino IDE</li>
</ul>

<p><strong>Hardware problems</strong></p>

<ul>
<li>Test using another Arduino</li>
<li>Test using another computer/laptop</li>
<li>Replace USB cable</li>
<li>The Arduino is (partly) broken, nothing much to do here</li>
</ul>
