Hi there and welcome
Can you tell me please the make and model of the device?
Please let me know
Ok, it is not showing any signs of life at all? Not even the splash screen comes up?
ok, remove the batteries then hold the power button down for 60 seconds then release.
Wait 5 minutes, put the batteries back in and try to turn it on.
Let me know the results please.
You do, there is not much else to be done if your 100% sure the batteries are ok.
It is either the power supply on the board inside (voltage regulator) or the power button. Usually the internal power supply
you will need to have it replaced sorry, getting it repaired is not an option as it costs more to repair then replace.
If you would like any additional information or assistance, please do not hesitate to let me know.
And if you can take a second to rate my service by clicking one of the stars at the top of the screen then submit, that would be greatly appreciated.