The most prevalent complaint on that camera is battery life.
The next time it happens, install fresh batteries and see it that fixes the problem.
If you are using AA Alkaline batteries, you should switch to AA NiMH rechargeable batteries.
You can buy AA NiMH batteries with a charger for around $15
When I turn on my Samsung Digimax s630 the screen is white & I cant see what Im trying to take a pic of.How do I fix it? Sometimes it shows a preview but its very hard to see & this very rarely happens.