Default [Q] sync manager ok but fastboot no device help please


my device HTC 802d china telecom, am based in china, running 4.2.2 upgrade 4.3 available

my phone says
SECURITY WARNING - this comes and goes

Phone working well, htc sync manager work well

when i go to bootloader then fastboot, it says fastboot usb but fastboot or adb says no device, i have tried using different cables, sync manager always able to detect and sync.

when connected to PC at bootloader then fastboot the phone does say FASTBOOT USB thereafter it dont accept any command, says no device .