I have this remote with my DJI FPV and used it a lot with FPV and with Avata, now I am using it for a Simulator connected to a PC and today after unplugging it from the PC it played dead with no reaction whatsoever (see the clip) but when I plug it to charger it works OK and shows endless (4-5 h???) charging - did someone had this is there a solution or I should buy new but I fly Avata 2 at the moment and this one was a backup for the old Awata ana DJI FPV

Looks like the batteries might be dead should be easy enough to replace them as they're standard 18500 iirc.
See here for how to take it apart:



If you have a multimeter, I'd test the batteries first before taking them out and if their voltage is within normal range (3-4.2V), send it to DJI for diagnostics instead.

Sounds like your remote went to sleep; I can hear it snoring.  

Hi, Alex. We're deeply sorry for the trouble that this has caused. In this case, I'm afraid that you may consider sending the RC in for a proper diagnosis. You can contact our support team to start up a ticket at https://www.dji.com/support . Also, the warranty can be applied depending on the outcome of the damage assessment including the warranty period of your unit. Thank you for your understanding

It happened that both batteries died after 4 years of service - the local dealer replaced them and now is OK!