<p>It seems like I blew the regulator based on the comment in the Reddit post: <a href="https://www.reddit.com/r/ender3/comments/ao5m5b/ender_3_can_only_be_powered_on_by_psu_and_usb/" rel="nofollow noreferrer">https://www.reddit.com/r/ender3/comments/ao5m5b/ender_3_can_only_be_powered_on_by_psu_and_usb/</a></p>

CC BY-SA 4.0
2019-02-07T23:44:23.003Z
2019-02-07T23:44:23.003Z
Benjamin Tan Wei Hao
<p>I installed a BLTouch on my Ender 3 following this video: <a href="https://www.youtube.com/watch?v=sUlqrSq6LeY" rel="nofollow noreferrer">https://www.youtube.com/watch?v=sUlqrSq6LeY</a>.</p>

<p>What I noticed too late was that when installing the BLTouch, I swapped the brown and red wires followed by connecting it to the mainboard.</p>

<p>Then I realized that the printer wouldn't turn on. After reading some of the comments, I swapped back the wire and I could see the BLTouch do its self-test.</p>

<p>However, it seems that I need to plug into the USB before the LCD + motors can work.</p>

<p>So is my mainboard fried? Or how should I fix it?</p>

<troubleshooting><creality-ender-3><bltouch>
Ender 3 needs Power Supply AND USB to work
Benjamin Tan Wei Hao
# Ender 3 needs Power Supply AND USB to work

(Asked by: username_0 on 2019-02-07)

I installed a BLTouch on my Ender 3 following this video: <https://www.youtube.com/watch?v=sUlqrSq6LeY>.

What I noticed too late was that when installing the BLTouch, I swapped the brown and red wires followed by connecting it to the mainboard.

Then I realized that the printer wouldn't turn on. After reading some of the comments, I swapped back the wire and I could see the BLTouch do its self-test.

However, it seems that I need to plug into the USB before the LCD + motors can work.

So is my mainboard fried? Or how should I fix it?

**Tags:** troubleshooting, creality-ender-3, bltouch


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## 1 answers

### Answer by username_0 on 2019-02-07. Score: 0 | Accepted answer

It seems like I blew the regulator based on the comment in the Reddit post: <https://www.reddit.com/r/ender3/comments/ao5m5b/ender_3_can_only_be_powered_on_by_psu_and_usb/>


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