If the battery life on the phone is not what it once was then a common issue are running programs using too much energy to run. The two main culprits are the 3G and Bluetooth settings. Just by turning these off you will get another one to three hours per charge out of your battery. Make sure to go through your settings and make sure they are set to as many of the battery saving options as possible. If this does not work then I suggest testing your phone with a new battery. Your current battery may be nearing the end if its life. For directions on how to change your settings visit LG CU400 Troubleshooting.
The most common reason for a white screen is a loose copper ribbon-wire in the hinge of the phone. To fix this, you will need to take the phone apart. Start with back and then continue all the way to the hinge. The ribbon-wire has two spots for connection, so start by making sure it is all the plugged in to both of those ports if you do not see any obvious damage to the wire. If the wire is damaged you want to purchase a broken model for spare parts. For instructions on taking apart the phone and fixing to ribbon-wire visit LG CU400 Troubleshooting.
You could be facing one of several issues. First you need make sure that wireless data is a part of your contract, and if it is, then make sure you have the phone’s 3G capabilities turned on. Also, you will need a minimum of two bars of signal for the browser to work on the LG CU400. If all of that is set then you may need to clear your cache and cookies because your phone won’t be able to access any data if it has nowhere to store it. I recommend visiting LG CU400 Troubleshooting for specific instructions.