We get questions like these every now and then. One said he signed into Dashboard, then click VIEW to view a blog, but only see a blank page. What I can suggest is to click VIEW > PAGE SOURCE (in Internet Explorer, it is VIEW > SOURCE) in the menu bar:
and a new window will open. Very likely, you may see a blank template or a truncated (incomplete) template. The template should always begin with
or something similar. Note particularly the second line
The very last line should always be
If the last line is not </html>, then part of your template is missing. If this is the case, you will have to change to a new Blogger template and your problem should be solved.
The other possibility is that your template may have become corrupted and thus your blog may display funny characters. In this case, First backup your template PLUS Page Elements. This post backup your Page Elements should explain the process in greater details.