Does wordpress have an error log?

There’s not one if you didn’t set one up. The codex has a good example of how to do this.

<?php
@ini_set('log_errors','On');
@ini_set('display_errors','Off');
@ini_set('error_log','/home/example.com/logs/php_error.log');

/**
 * This will log all errors notices and warnings to a file called debug.log in
 * wp-content (if Apache does not have write permission, you may need to create
 * the file first and set the appropriate permissions (i.e. use 666) ) 
 */
define('WP_DEBUG', true);
define('WP_DEBUG_LOG', true);
define('WP_DEBUG_DISPLAY', false);
@ini_set('display_errors',0);

White screen of death is usually caused by WordPress looking for the active theme and not finding it. If you can access the admin area, got to Appearance > Themes and reactivate your theme.