Magento How to debug blank white screen

Question

I have an error in my Magento backend that results in a blank screen (WSOD). I have set errors to on in admin but there is nothing being created in var/logs/. (I have checke

Answer 1

As you said - there is one stand alone answer to this issue.

I had same issue after changing theme. Memory was set to 1024 before, so that's not the problem. Cache was cleared and there was nothing useful in error log.

In my case solution was different - old theme had custom homepage template... Switching it to standard one fixed it.