Mediatek MT7688 keeps rebooting

Last weeks I create several firmware for MT7688 based router boards (different to MediaTek Linkit Smart 7688 DevKits).
The builds was based on openwrt

Target System Ralink RT288x/RT3xxx
Subtarget MT7688 based boards
Target Profile Default Profile

Until now I tried different ways getting LEDE firmware running, for example
Target System MediaTek Ralink MIPS
Subtarget MT7688 based boards
Target Profile Default Profile
same packages as with openwrt

After flashing different MT7688 based Board (8MB/64MB also 64MB/128MB) all boards keeps rebooting after loading firmware.
I already tried different boot loader.
At least I tried also your ...sysupgrade.bin same situation, keeps rebooting.

I checked out LEDE Project Forum also Issue Tracking System, maybe someone can reach me a helping hand.

Update:
I start over with new menu config and wrtnode2r bin is running

By the way YOU GUYS DID A GREAT JOB