Arrrgghh! This issue started a couple of months back and seems to be getting worse over time. When I first turn the scope on, my screen is filled with trash. Changing the vertical scale will change the size of the 'trash' for a second, then the amplitude of the 'trash' jumps back to the original size
??
The first 3 pictures were saved a few months ago. The last 2 were saved tonight. The trash seems to have changed a bit over that time. There is also about 1 subdivision (1ns @ 5ns/div) of jitter.
When it originally occurred, I did a CAL and it seemed to cure it for a few days but then it came back. The 'trash' disappears after about 10 minutes or so after power up. After the 'trash' clears up, if I power cycle the scope it doesn't come back. Originally, once it disappeared it simply vanished but now it's intermittently appearing for a few minutes before finally disappearing completely.
Something else I just noticed, at 500mV/Div. there is an artifact on Ch.1 (also on 2 if I set it to trigger on 2). I put on infinite persistence and took another screen shot (the last pic). During that time the 'trash' popped up a few times. Interestingly, I just now set the trigger back to channel 1 and the artifact disappeared, but re-appears if I go back to triggering on channel 2
.
When the problem appeared, nothing had changed like gel updates. Applying the latest 'update' supplied by the superlative Cybernet (
) had no effect on this issue. Because it appears to be thermally related, I suspect it's likely a BGA soldering issue. Since it clears after a little while I've just been putting up with it, but at some point I'll have to ship it back for warranty
. So far at least my heatsink retaining clips haven't fallen off!