Help! Devo 7e stopped powering up

I have a fully modified Devo 7e with A7105, NRF24L01, and swtiches. The modded Devo 7e has been working perfectly for 5 months. Today it won't power up. I opened and checked the transmitter but I don't see anything unusual. Does anybody have had similar experience or any suggestion what to check or do?

Thank you.

You may have burned up the small LDO thing that powers it.
Could you please open it up and take clear pictures of the insides.
We'll try our best to help

Here are some pictures.

BTW, I got it to turn on by connecting the battery cable after being disconnected for several hours. I can turn it on and off a few times but if I let it sit for a few minutes and try to turn it on then nothing happens. I am using 7.4 2S lipo pack for what it's worth and fully charged.

Thanks.

hi did you ever figure out what was wrong? same thing happened to mine thanks