How is your memory on the phone? Have you tried using a different cable? Uninstall and reinstall the app. It could really be a host of thing causing it. You'll just need to go through it one at a time to figure it out. Have you ever considered looking into a Crystal Sky monitor. They work very well, and are brighter than a phone or tablet. We have new and demo models in stock. Hope this helps narrow some of the potential issues down.