MacBook air dead with no power

My laptop died halfway through booting and then there is no trace of life. Magsafe when connected shows amber light but battery is not charging. Fan is also not spinning. Opened the system and checked the logic board found 5V missing. The DC in board shows 15 V but there is no 5V output. Is 5V supposed to be there as one of the outputs of the DCin board or it is generated in the logic board? I tested the DC in board output taking it out completely and connecting the magsafe adapter with no connections to or from the logic board. It shows two 15 V outputs only.