cx919ii random reboot

[iloveme3594]

Hi i Have a cx919ii with CYX_809 V5_2 20141105 Board with this rom: http://freaktab.com/album/500456-rom...9iii-rtl8723bs.
My problem is that the stick randomly reboots. Sometimes after a few minutes, sometimes after a few seconds. I thought that there is a heat problem, so i attached a heatsink on the CPU.
I used the Stock Rom and a few other working Roms with the same result. I tried to underclock with: AnTuTu CPU Master Free, Trickster Mod and a few other programs.
Maybe you could help me. I am helpless.
A few Weeks ago the stick worked fine, i dont changed anything.

[blinkone]

Hi & welcome to freaktab,Try another PSU of the same output,more often than not theses PSU's dont give enough power out that would be the first place to start looking Good luck.

[iloveme3594]

Hi i Tried another PSU, but the Problem is still there