R-JTAG Falcon stopped working

[JeDaj]

Hello,
I have a strange thing with my falcon console. It was running R-Jtag for almost 6 months without any issues. Lately I noticed that it won't power on when I hit power button or eject or from may gamepad. What is strange, that after a while (it took it 3 hours few times) it will power itself without me pressing anything. When it will power up it sits on Xbox360 logo. I had it booted to dashboard few times, but after shutting it down it would still lock on 360 logo at the beginning.
How can I check if it's a R-Jtag thing or maybe the console is dying?
Can I unsolder everything, load my nand from 6 months ago and check if it will boot up on stock? Or should I use JRunner to make most recent orig dashboard there?

Thanks in advance!

 

[Martin C]

You saved your original NAND for just this purpose. Write it back, desolder the CPU_RST wire and see what happens.

 

[JeDaj]

I did like you said. Now the console is powering up everytime.
I just thought that earlier it could be lack of hdd that the console hung on 360 logo. But the main problem is, why it won't power up with rjtag at all, or after random time form pushing the button?

EDIT:
I was too fast with my conclusion. I have took out power cord from console, put it back after 5 seconds and now the console won't boot up immediately after pressing the power button. It did power up after 2 minutes from there. I have changed the power brick from the other console, it's the same. It powers up after random time after pushing the button.

 

[Martin C]

I suggest you complete the support template so we can take a look at the install. The underside JTAG QSB is the one I'm most interested in.