Samsung Galaxy tab 10.1 Hardware or software problem?

This is my daughters tablet (I don't do computers without keyboards personally)

It's a couple of years old so not on the latest version of Android but has been working fine.

What is happening now is it will run for a short period. Then the screen will go black (back light still on but screen is black). After about 45 seconds it will come on again at the log in screen. You log in and all appears well for a minute or so, then the screen goes black.  It just keeps repeating this.

If you power down completely and re boot it will run for a few minutes longer before entering this never ending turn off and on cycle.

It is reporting that the battery is charged okay. I have just allowed the battery to go completely flat and now re charging it to try again.

I read somewhere about pressing power and volume + and there would be an option to "clear cache" but I have held power and volume+ until my fingers hurt and nothing happens. Should I be doing that when it's turned off completely, on standby, or logged in and working?

Anything else I can try. Only thing I can see is "factory reset" that will wipe everything.

 

Try this?

Ripped off the web, not sure if it works, I think my droid tablet is slightly different.

Boot Samsung Galaxy Tab 10.1 into recovery mode

Reboot your tablet into recovery mode, as follows:

Hold 'vol down' and 'power' buttons on tablet

Release 'power' when samsung image is shown

Release 'vol down' when the two icons are shown

Use the 'vol down' to navigate between the icons

Highlight the left icon (box)

Press the 'vol up' to select it and boot into recovery mode

but is that the factory reset that will wipe all apps and data?
 

I thought that it took you into a boot menu?

Where by you can select different options.

This takes you into the recovery menu on my Android Tablet.

Power off the tablet.

Press and hold "Vol+" button and press for ~5 seconds and release "Power" button.

After green robot appears - press "Power" button.

For navigate in Select Boot Mode menu use the "Vol+" button, select Recovery Mode and confirm selection with "Vol-" button.

Navigation in recovery menu - "Vol-"/"Vol +", confirm selection with "Power" button.