Re: 5116+5D10 intensity problem

Harvey White

You definitely want to look into one of two things, either bad/reduced high voltage (symptoms would be magnified deflection because a slower electron stream is easier to deflect), and then the cathode/grid bias, but right now, I'm betting on the high voltage.

I wouldn't change the horizontal or vertical gain, but I'd check the outputs of the amplifiers for normal signal levels.  I seem to remember that when the 5000 series was mentioned, there may have been some problems with an epoxy coated HV transformer, which may need to be replaced.  However, I'd check the HV oscillator circuit to see what's going on there.  If, for instance, there is an HV multiplier block (possible), feeding a separate accellerator, then failure of that block causes the image to bloom.

I'd suggest doing a search on the group archives for scope HV problems, which shows the steps you can take to troubleshoot the system.   You do need an HV probe.  It should be specified to work with the meter impedance you have, since it's a 1000 to 1 high voltage divider using the meter itself as the lower part.  10 meg meter needs 9990 meg resistive divider.

You might want to check the discussions on those, too, for additional information


On 2/16/2020 2:46 AM, Yeun-Jung Wu wrote:
Hello Harvey:

Since the intensity went down in recent event it never came back. What this 5116 did after turned on was nothing on the screen, even if the intensity control knob was turned fully clockwise. I can tell it was powered on only when scale graticule illumination was fully on.

I guess turn down the vertical and horizontal gain would shrink the display to normal siize. This couldn't be a cure since most important task is to restore a visible trace in normal viewing condition. Once the intensity problem was solved the graticule scale would be normal again.

I did not have any other 5000 series plug-in's. I bought this broken 5116+5D10 with smashed LCD color shutter a few years ago and fixed 5D10 digitizer.

I up load three photos under the file name 5116. Signal to vertical amplifier was interesting: an old video game?


Yeun-Jung Wu

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