This is a Troubleshooting page for the LG Optimus L90. It lists common issues with the phone, and then explains these issues in further detail. Use this guide to diagnose and repair common issues.

My touch screen does not register my finger placements on the screen.

Your screen protector may be the cause of the issue you are having. Remove your phone case and then proceed to use your touch screen. If your phone registers your finger placements, then your screen protector was the cause of your problem.

If your screen is stuck on one image and turns unresponsive, it is usually a software issue. Powering the phone on and off is a potential solution. If the phone’s display does not stay on or come on at all, then the lock button could be interfering. Try wiggling around the lock button or taking the back cover off the phone to see if there is anything interfering.

If the screen is physically cracked or damaged, then a replacement is usually the only fix here.

I am pressing the normal start up button, but my phone is not responding to it. The main cause of your phone not powering on is that your phone has a dead battery.

You need to know which piece of your charger set is malfunctioning. The two pieces are the USB adapter and USB cable. It is very common that you do not need to replace the whole set. Instead usually the USB cable wears out more quickly. This occurs because the USB cable becomes stretched, bundled, and pulled. The adapter is in the shape of a cube with not much wiggle room to tamper with. For most USB cables there is not much that can be done to repair a wire that has been damaged, and your best option is to find a replacement for it. The same can be said for the USB adapter if it is damaged.

The type of charger needed for this phone is a Micro USB cable with a USB attachment to plug into a USB adapter. This then can be plugged into a wall outlet having two or three pin spaces designed to allow insertion of an adapter.

If your USB cable and adapter are working fine, then you may need to replace your battery. This phone uses a Li-ion battery. To remove the non-functioning battery you must remove your phone case by tugging at one of the corners where the phone and case meet. Then in the center of the device you will see a large square silver piece of metal. This is your battery; there is a space for you to grab on to it and gently pull it out. Now just slip in your new battery and place the case back on. Your device should now be able to power on.

When I plug my headphones into my phone’s audio jack, I don’t hear any sound.

The headphone port on most phones is very prone to having dust and debris getting inside of it, which can limit the connection between the headphones and the port. Try blowing compressed air into the port to clear any debris. If the problem still persists, check the headphones to see if there is any malfunction on that end. If not it could be a software issue, so try resetting the phone. If none of this works, there is probably internal hardware damage which calls for replacement components.

Phone is presenting a message saying that SIM card is needed for an activity.

This phone does not specifically come with a SIM card. The SIM card needed for this phone is a Micro (3FF).

Make sure the SIM card is inserted properly into the slot. Make sure the prongs on the card match up with the ones in the slot to ensure a proper connection.

Camera application does not operate properly or at all.

If you take multiple different photos and there is a discrepancy in the same spot in every photo, then there is probably physical damage to your lens. The damage/debris is obviously in the same spot every time, which lets you know there is a scratch/damage/debris on the lens. This is most likely irreparable and needs replacement.

If you open up the camera app and get a black screen or if you try to take a photo and the camera is unresponsive/not working, then there could be damage to the hardware or software portion of the phone that relates to the camera. Try closing background apps, restarting the phone, or backup data and do a factory reset. These methods should rule out any basic software malfunctions. If nothing is working, then there could possibly be internal damage to the camera’s hardware. This would most likely require replacement.

Some components and applications on the device will not work due to the physical damage sustained to the motherboard.

Unfortunately not all devices will work properly from the factory as some defects and part failures are only noticeable after they’ve been sold and used by a good number of people. These kinks are usually worked out after the manufacturer has received enough data to prove that there is a consistent problem. If your device is fairly new and you start to encounter premature hardware or app failure, than you could have one of these faulty devices. Another huge cause of motherboard damage is when your phone falls. The motherboard contains some of the most fragile components and connections on the device so a hard fall and the ensuing vibrations can cause some physical damage pretty easily.

With many different chargers being available today it can be easy to use a charger that is not optimized for your phone. The charger may fit into the phone but it may only charge up to a certain amperage. For example, if your phone requires a 700mA current but your charger only supplies 500mA then many issues many occur such as slow charging, overheating, and complete device failure