Sometimes camera might not work for some glitches and it can be easily fixed by restarting your phone. I had the same problem with my new BLU F91 5G mobile but it's now fixed. Please do it and that's easy. If it doesn't fix the problem then you will have to reset your BLU phone, that's the only option left. Still the issue is not fixed then please contact BLU if the phone is under warranty. Finally if it's not under warranty then you can't do anything except replacing the camera module or chip. The best thing would be to get a new phone instead of BLU Studio 7.0 II

Yes, there are all things which you can do related to laptops from small to major repairs. One of them included is the headphone jack problem. You can fix it and I would recommend approaching to a normal laptop repair vendor but not the official laptop service center which would eventually cost more. Simple and affordable solution. Search for laptop repair on your mobile phone and bingo Google Maps results.

Perhaps the best way is to Google this and as I did that, I found a few helpful results. The first result definitely leads to this iFixit page. But the second result leads to a page on BLUCellPhones.us website. I don’t believe this is the official website of the BLU phone company but yeah definitely the page has a solution on how to fix BLU phone problem commonly found like BLU phone wont charge, it keeps restarting and others. According to website data I found, it mentions that when your device keeps restarting means that it’s stuck in the boot loop. This is a common Android error found on not only BLU but also other brand phones as well.

3.4 minutes is too long. It would have been better if you could have told your PC specs and how old is it. Slow issues can be fixed by - (1) Uninstalling programs that you don’t need. (2) Use one browser instead of two or three. (3) If on Windows, use classic settings and layout for faster speed. (4) Don’t store items on desktop, keep your C drive or desktop clean. (5) Move items to other drives from Download folder, My pics folder. (6) Check for low disk space and free up space. other steps are mentioned at this youtube video - https://www.youtube.com/watch?v=cvf0VmmQ... https://www.youtube.com/watch?v=e1ePF1q-TTk

Check the charger if it’s working or not. This can be divided into two types - (1) Software failure (2) Physical failure Software failure might happen when you have installed glitchy software the device might fail to turn on. Simply go to recovery mode by pressing the Volume UP + Power button together and delete or factory reset from options available. Physical button failure also leads to a device not turning on. In such case there is really a little you can do. If it still doesn’t work then there is nothing you can do really, except buy a new phone.