Tektronix THS720A power-up problem

[TekWal]

I need some advice from the forum.

Just got a nice THS720A for my daughter project. It is experiencing some weird power up behavior.

The scope works fine but occasionally, it will just refused to boot up. Pressing the on/stdby button will just light up the backlight and nothing happened. I need to unplug the AC adapter and then plug in again with the on/stdby button pressed. After that it will works fine. Self-test PASS and there is not error messages on the error log status. Whenever the problem return, I will have to do the AC adapter unplug then plug-in + on/stdby button pressed fix. Just to add, there is no battery in the scope.

Anyone experienced this problem?

Anyway comments/feedback is much appreciated.

Wally