iphone 7 dead, not charging, not starting up

Battery?

If it is "dead", I suggest that you make an appointment and have your device / battery inspected at an Apple Store or AASP (Apple Authorized Service Provider) among this list:--> Apple – Location Selector

After checking it out, they'll give you all the available options.

Regards

Giulio

f5nw1x ~ If your iPhone 7 still has its original battery, it likely needs replacing:

iPhone Battery & Power Repair

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We, just users like you, cannot diagnose that kind of problem remotely, sorry.

As already suggested, your device might need to be inspected deeply.

Bets of luck.

Giulio