Power button circuit seems dead (Android tablet). How to check it?

[gilga]

Hi!

I've got an Android tablet (discontinued Archos FamilyPad 2: https://www.europeanconsumerschoice.org/...).
I've let it fall some time ago and now it can't turn on anymore.

the symptoms:

- Pressing Power On button: nothing happens, screens stays black.
- Pressing reset, Power On for 10 sec, pressing Vol+ and Power On (as I've seen it can power on sometimes): nothing happens.
- charging the tablet: there's a red light showing that it charges. I've tried to leave it for 2 days: it still can't turn on.
- Plugging the usb to the PC (windows or Linux): the tablet is not detected.

I've checked the battery with my multimeter, and it displays +4V. So I guess it's okay.

View attachment 32705
I think I should look at the power button itself and the circuit connected to it. I push the button, nothing works. How can I check where the problem is? Maybe trying to trigger the POWER signal without using the power button itself?

Thanks a lot for your help!

 

[garublador]

You can check continuity across the buttons when left alone and then again when pressed to make sure the switches are working. My guess is they are.

My experience is that most, if not all of the Android devices I've seen will power up when connected to external power and/or USB. If it isn't powering up then it's probably something else. Given that it doesn't show up as a USB device it probably isn't that the screen isn't working.

 

[Bluejets]

Voltage does not sound right. What is written on the batteries and what connection.