Most likely the keyboard is defective. If under warranty, call Dell for a replacement. If not, the keyboard is inexpensive from sellers on e-Bay. Replacement is not difficult.
I HaVe a Dell STudio 1737 lapTop. ReCenTly, THe "CVH & T" keys will only respond wHen I use THe sHifT key. THey do noT respond wHen in Caps LoCk. Any ideas?