We have a new community article that shows you to configure AEM so it write out to a new log file. See this article:
Developing a custom Adobe Experience Manager Quiz Component
In this article - notice this section at the beginning of the article:
C - The location where application configuration information is located. For example, notice this node: org.apache.sling.commons.log.file. The value is logs/project-aemquiz.log. This means that log information is written to project-aemquiq.log. So when looking for log information, be sure to check this log file.