Shuts down when screen is shut off and phone is connected to charger

User complained that device was unresponsive. Connected device to USB, no response. Was able to launch into recovery mode, and restore factory image. Phone now powers on, but shuts down when connected to power source with the screen off. Device will not power back on unless I disconnect, and reconnect power source. There is no physical damage to the phone from what I can tell, though I fear I've exhausted most of my options. Any ideas before I advise user to replace the device?