I learned a few more test results for my 1013d.
1. At frequencies above 30mhz, both channels
It comes out normally. (Previous article)
2. If the frequency is lowered by about 10mhz, a glitch occurs in the second channel at the bottom. (bottom.jpg)
3. Drag the lower second channel on the screen and raise it to the center to change the shape of the glitch. (middle.jpg)
4. Drag the second channel and move it toward the top first channel to remove the glitch. (top.jpg)
5. Turn off the first channel and use only the second channel to avoid glitches. (single.jpg)
6. If noise is applied to the first channel and a square wave is applied to the second channel, it is affected by the noise, and the waveform with noise is also seen in the second channel. (noise.jpg).
When I connect another oscilloscope to the second channel, there is no noise.
From the above facts, I came to the conclusion that this is not something that can be fixed by replacing one or two parts.
My 1013d seems to be an early pcb type. I know that the most recent release is shieldboxed in the opamp area.
Facts like this make me sad. ~~~