mb_enabled crashes site with white screen

Where exactly in the .module does the mb_enabled code go?

I added to my .module:

/**
 * Implements hook_block_info().
 */
function dexp_layerslider_block_info()
{
  $blocks = array();
  $num    = variable_get('dexp_layerslider_block_num', 3);
  for ($i = 1; $i <= $num; $i++) {
    $blocks['dexp_layerslider_block_' . $i] = array(
      'info' => t('Layer Slider block ' . $i),
      'cache' => DRUPAL_NO_CACHE
        'mb_enabled' => TRUE, //Default
    );
  }
  return $blocks;
}

function dexp_layerslider_block($op = 'list', $delta = 0, $edit = array()) {
  $multi_id = isset($edit['multiblock_delta']) ? '_'. $edit['multiblock_delta']['#value'] : NULL;

  switch ($op) {
   
    case 'mb_enabled':
      return 'mb_enabled';
  }
}

But all this does is bring the site down with a white screen of death.

The error log reports
PHP Parse error: syntax error, unexpected ''mb_enabled'' (T_CONSTANT_ENCAPSED_STRING), expecting ')' in sites/all/modules/drupalexp/modules/dexp_layerslider/dexp_layerslider.module on line 164

Is there a cleaner way to do this?