We may be able to help you if you can list the problems you are having. I'm assuming you're getting a poor display or no display at all on your lcd? Also assuming the problem isn't fixed when using an external monitor. There's probly not much we can do on that end but it's worth a shot, lots of good minds on here.
As far as it being worth it, you really don't seem to like lugging around a laptop of that size so it probably isn't. You can maybe sell the laptop as-is on ebay for a decent amount and put that towards a new smaller laptop. I used to have a heavier 15.4" myself but I've got a very slim 12.1" notebook and even though it's slowe rthe portability is amazing. I'd never go back to a big notebook.
As far as your possible new laptop, what games etc. are you interested in playing on it, if any? You can still get a decent dedicated vid card on a 14.1" laptop or even smaller. You could do something along these lines:
Newegg.com - ASUS F8 Series F8SV-A1 NoteBook Intel Core 2 Duo T7500(2.20GHz) 14" Wide XGA 1GB+TM1GB Memory 160GB HDD DVD Super Multi NVIDIA GeForce 8600M GT - Laptops / Notebooks
But it's all about what you need and what you are willing to spend. For brands I like MSI and Asus the best. They are very high quality builds, going for quality over quantity. Asus' new models look great and they have a 2-year standard as well so great if something does go bad. Most other brands only have 1 year standard.