VPA Red Pointer Problem ,,,,,

Hi Nagra User,

One of my VPA have a strange symptom,,, When i power up the VPA and turn to MUTE, one of the VPA in which the RED pointer will rise to the middle of the meter ,,, After 30 minutes,,, the RED pointer return back to the " 0 " position ( Green Zone ) and step together with the BLACK pointer in the small green zone ...

If any expert of the VPA user have this problem ,,, or you can help me knowing what is the problem in side.....Is it the VPA problem or it is the Chinese Original 845 tubes problem......

The VPA after power on and warm up for 30 minutes ,, DOES i need to do the same step every times ,,,, Very strangee ,,,,,, it is working fine and without any problem,,, the unit is BRAND NEW , only used for less than 100 hours,,,, Does the VPA need burn-in period....... It would be appreciated for any VPA user can share their valuable knowledge with me.

Your kind message is highly appreciated..
Contact Nagra. The red pointer should not be out of the green zone, and certainly not in the middle of the meter !

this is not too unusual , although the pointer should return to the green zone after a few minutes of start up.
Is it the Original Nagra 845 tubes problem ? I used it with the KR845 (quad) ,,, never have this problem,,,very strange for me ?
Nagra stooped the use of KR tubes as they were having too many problems.