First, the model number you supplied, KV-34XTR10, is not a 50 inch set but a 43 inch tube set.
Secondly, the symptoms you relate of have audio but no video - or that it comes on late, and gets longer as time goes by, is related most often to failure of the high voltage system. The repair nearly always revolves around the flyback transformer and/or the horizontal deflection amplifier (the horizontal output transistor, for example).
The best repair method is to replace both the flyback and the horizontal output transistor because if only one is replaced it is common for the other to fail soon thereafter.
PS: You should visit www.fixya.com, there you can get further information about this problem. If you need a technician service , you can visit this website www.tvrepairjacksonvillefl.com and have more details of what is going on and what it would cost to repair.
Let me know if you have further questions.
andrés
November 2012