I was jinxed by Mark
![Embarrassed :-[](https://www.eevblog.com/forum/Smileys/default/embarrassed.gif)
, I pulled my modules to start a calibration on a recently finished scope and my time mark generator didn't work.
![Angry >:(](https://www.eevblog.com/forum/Smileys/default/angry.gif)
This generator was dead when I got it a few years ago, I repaired and has been working with no problem until now. Last time that I used it was about 2 months ago. Is probably my brain that is not working but I can get past this.
I have included the part of the schematics were I having the problem. This is just at the end of the signal gets passed to the marker out BNC. I have disconnected the cable that ties J468 and P468 to isolate the problem. At CR470 to the side of J465 I get the marker (picture DSC_1149) at the other side I get picture DSC_1150, this is a .1mS markers, is like is a capacitor there. With a lower speed about 1mS the bottom drops to 0V. I go to a higher speed I end up with a flat line at about 3.5V. Just in case the other side of CR468 is sitting at 0V with no signal there.
Because there are very few parts there I thought that CR470 was acting as a capacitor, I changed the diode but did not solve the problem. I used a 1N4148, the Tektronix Cross Reference page calles for a 1N4244, but I don't think that is the problem.
Is anyone experience something like this?