iPhone 4 power button issue

Hi Pawel,

You can almost certainly fix this yourself, and iFixit even has all the guides you need to do that job.

The biggest problem here is that first you'll have to figure out which part is broken. The power button consists of a mechanical button, the part you press with your finger, and then there's the electrical part which is basically a small metal dome that the mechanical button compresses to make the electrical connection. The two parts require very different approaches to fix; it's not too bad of a job to replace the mechanical part, but if its the electrical domed switch itself you have to pretty much gut the phone to get to it.

I'd suggest following the guide to replace the mechanical button first, and once you get to the part where you remove the electrical switch, you can evaluate whether it's the mechanical or the electrical part that's gotten damaged. It could even be just the bracket that holds the electrical switch in place that's been bent. If it's just a bent part, you may be able to straighten it, but if something's broken you may have to order parts, which should be pretty easy to get.

Here's the guide for the mechanical part of the button.

iPhone 4 Power & Lock Button Replacement - iFixit Repair Guide

If that doesn't do the job and you end up needing to replace the electrical switch, then use this guide to do the repair.

iPhone 4 Power & Sensor Cable Replacement - iFixit Repair Guide

As far as parts, like I said they shouldn't be hard to find; I'd suggest starting out checking Amazon, eBay and AliExpress, depending on where in the world you're located and what's available to you.

Good luck; let us know how it turns out!