# New Unicorn Hat not working

**URL:** <https://forums.pimoroni.com/t/new-unicorn-hat-not-working/2317>\
**Category:** Support\
**Created:** [May 2, 2016, 9:30am UTC](https://forums.pimoroni.com/t/new-unicorn-hat-not-working/2317 "2016-05-02T09:30:51Z")\
**Posts on this page:** 1\
**Showing post:** 25

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**Author:** ![gadgetoid](https://sea2.discourse-cdn.com/flex016/user_avatar/forums.pimoroni.com/gadgetoid/32/13_2.png) [@gadgetoid](https://forums.pimoroni.com/u/gadgetoid)\
**Post date:** [May 19, 2016, 12:55pm UTC](https://forums.pimoroni.com/t/new-unicorn-hat-not-working/2317/25 "2016-05-19T12:55:55Z")

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@traptest it might be worth trying to clear out old versions of the library first, perhaps. It also depends if you’re using Python 2.x or 3.x since “pip install” will only update the library for 2.x.

If you’ve got a revision 0x13, Model B+ then this fix will certainly be the one you’re looking for. Try running the following to see what revision you’re running:

```auto
cat /proc/cpuinfo | grep Revision

```

You can try reinstalling the library for Python 2 and 3 like so:

```auto
sudo pip uninstall rpi_ws281x
sudo pip3 uninstall rpi_ws281x
sudo pip install rpi_ws281x
sudo pip3 install rpi_ws281x

```

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