iPhone 5 black screen (with broken power button)

I am trying to repair an old Iphone 5 that stopped working about a week ago. It was plugged into the charger at a low battery. Reportedly, it was constantly buzzing while on the charger (sounds like a poor connection), and eventually just ran out of battery. Otherwise it had no problems before. The problem is that the device now doesn’t start back up. When I plug the device in, nothing happens at all, even after I left it plugged in for a couple of hours. The charger does work on other Iphones.

Usually just cleaning the charging port helps, but that didn’t solve the problem.

My first thought was that the charging port must have simply worn out, so I replaced that (this went without problems, not the first time I have replaced one), but with no results.

I had replaced the battery about a month or so ago without any problems. On the contrary, the battery life was back to normal, so I do not expect the battery to be the problem.

I currently do not have any spare parts or donor devices, so if I can simply measure something through or try some other troubleshooting methods that would be ideal.

Now what makes this case a bit tricky is that the power button is broken. Because of this I can’t manually turn it on or reset it, it can only turn on when it is plugged in and working properly.

If the phone is truly broken, I will just get a replacement. The problem is that it has some data on it (a couple of images, some notes and some app-specific local data) that I don’t think I can recover unless I get the phone back to life. I hoped to be able to retrieve some things via Icloud, but I am fairly sure I disabled Icloud for a number of applications, and my account turns out to be secured via an old phone number, because of which I can’t receive the security code to acces the account. If you know of any ways for me to recover this data anyways, that would be fantastic too!

Thanks in advance for any help given (: