Re: 2467B Trace flicker


 

In a previous post you described noise on the DIA signal and high frequency noise on the DI signal.  You have to quiet that noise before any other intensity measurements can be meaningful.  If DIA in noise free you can check the Z-axis by putting a test scope on The Z-Axis outputs (test points 65 and 66 in the service manual).  The Display sequencer and a few other parts CAN give you screen flicker but they don't put noise on DIA and they usually present other problems too.  So, if DIA is quiet, and test points 65 and 66 show proper waveforms with little noise in their amplitude, try other sweep speeds and see if the flicker "walks" across the screen.  
Step 1:  Obtain clean, noise free DIA signal.

On ‎Monday‎, ‎January‎ ‎21‎, ‎2019‎ ‎09‎:‎53‎:‎36‎ ‎AM‎ ‎CST, thespin@gmail.com <thespin@gmail.com> wrote:

Is there a good way to trace whether it's the z-axis hybrid, the display sequencer, or the front panel DAC subsystem?

On Fri, Jan 18, 2019 at 12:02 PM, victor.silva wrote:


Issues like you describe are usually related to a display sequencer (U650).
In my opinion I believe this is selected part.  I see many 2465Bs with the
display sequencer chip with a green thick magic marker line on it.
2445Bs do not normally have that mark on them.

--Victor

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