HST will not power on

My Viavi HST will not power on. I press and release the power button but nothing happens.

If the HST will not power up and the unit is on battery then plug in the AC power adapter and try again. If the unit does not attempt to power up on AC (backlight comes on in the display or leds above the display show activity) then unplug the AC adapter and the remove the battery. Inspect the the connector pins for signs of damage and then reattach the battery. If the unit will still not power up on AC then check the power button to make sure it is not stuck. You should be able to feel the button depress and then come back up as you press and release it. If you have access to another HST then try the battery from a known good unit. If the HST power up on another battery then the old battery needs to be replaced. If the HST will not power up on a known good battery then the unit will require service.