Phone not powering on
You are unable to power on your device.
Battery life shortened or nonexistent
If your Blackberry does not turn on, then your phone could have a bad battery. Try charging the phone, it could be drained. Your battery could also be bad if battery life drains unusually fast after a full charge. If your battery has gone defective or is bad, simply replace it with a new one.
Display not coming on
If the screen looks like it is turned off, even though the phone is clearly on (buttons are lit, generates sound from alerts, etc.), it is possible that the display has gone bad. If you restart the phone and the display is still cut out, then it is possible that you have a bad display. If your display has gone bad, you'll have to replace it. You can find a guide on how to do that here.
Power button is stuck or not making contact
It is possible that something came loose on the inside of your power button, and is preventing the button from making contact with the inside of the phone. If the button is stuck, try to keep pressing it in hopes that it comes loose by itself. If you think that it's not making contact with the switch, you're going to have to take it apart.
Logic board has gone bad or is faulty
If your device does not turn on at all (screen is off, buttons don't light up, no sound is emitted from the device), this could be a malfunction of the logic board. Test your battery in another phone to verify that it is not a power issue. If you really believe the logic board has gone bad, you'll need to replace it with a new one.
Your device does not produce any sound, regardless of volume setting.
Headphones are broken or faulty
The wires inside of your headphones could be frayed, causing them to lose contact. Try a different pair of headphones, or test your headphones on a different device, in order to isolate the problem further.
Speaker is not producing any sound
If no sound is emitted from your phones speakers, then they could be faulty. To isolate this problem, plug in a pair of headphones into the auxiliary jack. If you know that both your headphones and auxiliary jack are in proper working order, then the speakers are your problem, not the software of the phone.
Auxiliary port is not recognizing any connections
It is possible that the port where you plug in your headphones or other output device has gone bad. Water entering the port (such as during rain) could cause the connection to go bad, as well as dropping the phone. Make sure that the port is clean of debris/dust. If you are still having issues, then it is likely that the port needs replacing.
Poor quality pictures
The quality of your pictures has degraded since acquiring the phone.
Picture clarity is not present
If pictures are coming out blurry, clean your lens! It is possible that dirt or oil from your fingers is obstructing the lens from having a clear view.
Lens is broken
If your pictures are coming out distorted, check your lens. If your lens is cracked or uneven, this can distort image quality greatly. You'll need to replace the lens if this is the case.
Camera has gone bad
If there are black spots or lines showing up in your pictures, this is likely due to a defective camera. You'll need to open up your phone and replace it - make sure to take a look at this guide!
Keyboard not registering button presses
You are hitting buttons, but the phone is not recognizing your inputs.
If crumbs or dirt build up between or under the keys, it can prevent them from making contact with the phone. Check that this is not the case; if your keyboard is dirty, clean it!
If your keyboard is clean and free of dirt, the connection between the keyboard and phone could have gone bad. This is likely the case if you know there is nothing obstructing key presses. In order to replace the keyboard, you'll have to follow the steps in this guide.
If you are missing buttons, you will have to replace the whole keyboard, as keys are not sold individually.
Device is overheating
Your device gets uncomfortably hot, and is difficult to hold in your bare hand.
Plugged into charger for far too long
Make sure you disconnect your phone from the charger once it has reached a full charge. Leaving your phone plugged in to charge for too long can lead to heat issues, and also reduce battery life.
Left in a hot place
Your phone is bound to get hot if you leave it on a table outside in the sun for a few hours, or in the car on a hot summer day! Try to store your phone away from harsh sunlight, or areas where the buildup of heat over time is an issue.
Buildup of dust or dirt
If there is a lot of dust or dirt built up in the ports outside and inside of your phone, it can prevent heat from escaping. Cleaning these ports can allow for more airflow, and lower phone temperatures.