LG cu 515 screen just lights up, no details, or just squiggly lines . Phone works, otherwise.

This fault is technically called 'retraced lines'. There are many reasons for this fault. It will be best to contact any service technician. If the screen voltage to CRT is abnormal [higher than normal]; this kind of fault can occur. If you wish to get some details; check the site linked here. Pull up older posts. Surf the site with patience. http://electronicshelponline.blogspot.com/
One among the post have details about this fault "Retrace lines with picture".

Service manuals for cellular phones are not available unless you are a service tech for the company. This becomes a legal matter at that point.

http://us.lge.com/download/product/file/1000003408/CU515_UG_E_1.0.pdf

lg website have all the manuals for their phones

When you are on the message screen, there is a little orange block on the upper right corner that (at least on mine) shows "Abc".

If you press the # button, it will cycle thru "ABC", then "123", then "abc".

If you leave it on "ABC". then you have all caps.

take the battery out for a minute, then replace. ushould be okay! good luck champ!

You can send yourself the settings for the internet and email. Make sure you choose internet and not "vpn internet" unless you have a VPN. If you don't know what a vpn is you don't have it.

Log in to t-mobile.com
Go to support.
Go to services and data
Go to device setup tools
Go to Begin to use the T-mobile wireless configurator
Choose your phone and send settings

connect the phone without the driver - my lg cu515 works without it
however, i believe the driver is ready to install on the phone and will be automatically installed when you connect your phone to the computer.

you may need to try master resetting the mobile and clearing all paired devices then try again

Yes you can download it from : LGmobile http://uk.lgmobile.com/web/web.mypage.RetrieveMyPhoneList.laf
Just look up your phone model and should be able to see the downlodable PCsuite for any of your LG phones.