2 x apple iphone 4 wont turn on - please read +

i have 2 iphone 4 one white one black, bought these for me and the mrs, got them home to charge them and both of them wont power up. they are 16gb and 32gb models. and lead to believe both unlocked to all networks. you might be able to fix them or use them for spare parts will listen to offers please ring 07765612139