AnsweredAssumed Answered

Gain problem

Question asked by spro on Mar 26, 2008
Latest reply on Mar 27, 2008 by tjw
I just acquired a HP 54600B scope, and could really use some help trying to get this thing working.  Everything seems to work fine except:

1) When I run the self-calibration it stops at "Calibrating gains for 0.500 V/div" (channel 1) and just sits there with a trace bouncing back and forth above and below the center mark, and the number in the upper right fluctuating between ~41.8 and ~42.0.  I left it go for several hours just to see if it would time out, and it didn't.

2) When in connect channel 1 to the test square wave and decrease the Volts/div from 5V to 2.00V, then 1.00V, the wave on the screen appears larger and larger on the screen (as it should).  However, when I go from 1.00V to 500mv the wave gets smaller.  Then from 500mv to 200mv it starts to get big again but is way off (showing about 600mv peak to peak instead of 5V).

So something is fishy about the 500mv/div.  I expect there might be a hardware problem, but maybe there is some tuning or further tests I can do to diagnose the source of the problem?  Also, if I could just somehow get it to skip through that step in the calibration that is gets stuck on, it might continue on to calibrate channel 2, and I could get at least one usable channel.

Thanks in advance.