Samsung Warranty - Internal Defect on Phone With Cracked Screen

[ash9002]

My phone has stopped turning on or charging due to what I'm assuming is an internal fault, which is covered by warranty. However, the phone also has a cracked screen, something which is not covered by warranty. Will Samsung be able to repair the internal fault while leaving the cracked screen or do I need to repair the screen first for my warranty claim to be valid. If I do need to repair the screen, does it have to be via Samsung since I've heard that doing it via 3rd parties will void the warranty. Thank you.