TL;DR - try these:
- Drain the battery (let the tablet play some video until it turns itself off) and leave it alone for 2 days before charging it again
- Once you get the screen working (by pressing many times the power button), increase the brightness. (If you have an HDMI adapter or a remote access program, you can probably do this even with a black screen, but I haven't tried this yet.)
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I've had what seems like this issue since 2018, but I'll add my details, as they might help others.
What I saw: Many times the screen stays black when you try to turn it on, but, if you are in a really dark room, you can see for a split second that it's starting to light up before turning back black. Another fun fact: when it is in this state, everything seems to work normally except the screen being black. For one thing, with a remote access program installed, I could see that the tablet responds to touches.
So what did I actually do from 2018 until now? Initially I would press the on/off button many times (sometimes hundreds), until I finally got the screen to light up. But then I noticed things and made some adjustments, and it really helped, to the point where I decided not to try and have it fixed under warranty, as I was supposed to mail it in and I was pretty sure they would see that it starts and send it right back. What I did:
- Let the battery drain without recharging it, left it like this for a day or two, then charged it again
- Started the tablet, played a lot with the on/off button, and, when finally I got the screen, I increased the brightness (I was using a really low, fixed setting)
This pretty much did it for me, with one additional caveat: If it turned off the screen automatically after some time of inactivity, that was a pretty sure way of getting back this issue, but fortunately it would recover; if not immediately, after several hours. And then things would be OK until the power saving kicked in again.
So what brings me back? I was hoping to see a proper solution to this. About 1 month ago it started doing this again, and now increasing the brightness more didn't really help (but turning it down made it way harder to get the screen to light up). Still, it wasn't as bad as it was back in 2018. I didn't drain the battery at first, though. After doing that, the screen always came up on the first attempt (so far), but I haven't used it much.
