Player turns off after pressing any button
 

I have unbranded 1.5 Nano clone named "Car MP4 player with FM transmitter". It's firmware broke up, so I had to install a new one. There is no board name inside, and by lots of testing I found that compatible if firmware for B002-5 board (t29_h66_j1) . Then I found out the suitable dump: Full version 3.5.37 firmware for 1.5" LCD . But now my player turns off (with logout animation) in 5 seconds after pressing any button,
The question is: what can cause such a problem?
BTW, it's probably not battery, because it won't turn off if I just turn it on and don't press anything.

And other question. First stage firmware (t29_h66_j1.fw) is marked 3.5.37 version. Does it make sense to install *.bin with 3.5.35 version?

Owh, I make some progress in this.
My player has ATJ2051H chip and firmware I flashed is for ATJ2085, or something like that, The reason is button order. At my configuration 01 is code for "Off button", as I think. But 01is binded to some periodical action (as I understand it have to be key scanner or something like that).
So, if I change this value to 00 in KY_HARD.DRV, player stops turning off.
And now I have the other problem: only one Next button works by default. By some tests I found out codes of Previous and Play button.
But they don't work properly, they work only being binded to physical Next button. I think it happens because of that damned keyscanner (kind of there must be something to scan other button codes). If someone knows how does keys system work (even on ATJ2085), please tell me little about it, and if possible, point me to key table for my chip.

Now it's nearly done :)
I took KY_HARD.DRV from S1 Mp3 3.5.37 Wilson Co. Ltd. Firmware and put it instead of the local one. But I had to remap some keys also, and now it works fine.
Last trouble is Volume button - I didn't find what code is answering for it. So if you know, please, tell me its code.
Also, if you need such a firmware, I can send you it by email.

Thanks Conscio for updating us on all of this.

Can I ask how you went about editing the KY_HARD.DRV file?
Where did you get the file from? Because I don't see it in the download link from your original post so I'm interested where you got it from.
It's interesting to hear your findings because this part is new to me.