I a using as raspberry pi 3 model B and I think I have tripped the poly fuse as I connected it to a nine volt battery pack and a 5 volt extension. I waited for the poly fuse to reset itself for like six to seven days but after that I have no luck....So I started to wonder if there is a way to manually reset the poly fuse. my mother is saying that we should get a pi zero or replace the poly fuse.(PS- my mother is the best engineer and programmer I have ever met). so I told her that I would post the Query here on how to reset the poly fuse. Please Help this is my last hope or goodby Raspberry Pi 3.....

1 Answer 1


The polyfuse will not protect you from connecting 9V to the Pi. Its purpose is to limit current, not voltage.

The Pi is likely dead, having been destroyed by the application of 9V.

If the polyfuse had operated to limit current it would have recovered after a day or so.

It is never safe to feed over 6V into any Pi, regardless of whether they have a polyfuse fitted or not.

  • So now I will have to buy a new Raspberry Pi?
    – Krish
    Commented Jan 27, 2018 at 6:32
  • If it is showing no signs of life after more than a few days from initial problem then it is terminal. You need to buy a new Pi.
    – joan
    Commented Jan 27, 2018 at 8:41

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service and acknowledge you have read our privacy policy.

Not the answer you're looking for? Browse other questions tagged or ask your own question.