Hello Rcrousore,
The TV remote does not need resetting at all. An LG remote is already programmed to work any LG TV. Make sure that the batteries are new , I can't tell you how many times I purchased batteries as new and after testing them one if not both were not new at all, very annoying! Did you press the TV button on your remote to have it set for functioning your TV? Programming the cable remote to work your TV does not change anything with regards to your original TV remote. You may also want to check that you're not in STB mode, but that is why you should press TV on the TV remote! You didn't leave any batteries in the TV remote while you were not using it by any chance? Sometimes when batteries are left in a remote or unit for a while without operating it, they leak and the caustic alkaline or battery acid can destroy the inner components...IFV

The LG 42" 1080p LED 120Hz HDTV Model # 42LN5400 has 1920 pixels horizontally and 1080 pixels vertical. If you multiply these 2 numbers, you'll have the number of pixels in total which is just over 2 million pixels at 2,073,600. Thats why some people refer to these as 2K TVs!...IFV

Thanks for your interest in the 42" 1080p/120Hz HDTV. I was wondering which model you have in the 42" but not that it matters for the answer to your question in this instance. Should you have further questions about your TV in the future, I would advise you providing a model number, it will prove extremely useful.
Contrary to popular belief, electrical components are not immune to weather conditions and depending on how long your TV was exposed to the weather and in particular, the severity of the weather, it is possible some components may have died or degraded due to the exposure. At the beginning of every TV manual, you will notice there is a disclaimer given and an optimal operating temperature is always provided for the TV. In my previous job, I always advised my customers that if they were going to keep the TV in its box in the garage before giving it as a Christmas gift, that they let the unit warm up and adjust to room temperature before turning it on to prevent the screen from cracking from a sudden jump in heat when the unit starts to operate and to avoid damaging the internal components for the same reason. IFV