So, I didn't really want to get into any oscilloscope operation training, because I'm relatively novice at it myself...I realize you're not necessarily expecting or asking me to do that, but if I were you I know I'd be hoping...been there dozens if not hundreds of times on various issues/projects. I want you to read your scope manual, watch YouTube videos...whatever...to elevate your understanding of how to use and operate your oscilloscope. I'm not meaning to be condescending or anything, I'm just pushing you, because you have it, you're using it, I think you want to understand it better, and I want to help you but I've got limited time and your last post causes me to ask a lot of questions. When you are posting updates *please* be as agonizingly specific as possible, because the details really do matter...making assumtions about what somebody means in this medium and process is just a bad waste of everybody's time.
...you can see the square wave cal reference. This is measured at 5mV with the potentiometer all the way to the right.
*What* is 5mV? The channel 1 VOLTS/DIV control? If so, do you understand what that control does and what those settings mean with that control? And by "the potentiometer" are you talking about the channel 1 CAL control? I *think* that's safe to assume, but I've wasted too much time making assumptions when it turns out I wasn't clear or somebody didn't understand but was apprehensive to just say so, and/or they thought I meant something else and I think they mean the same thing I think they do...ugh.
If my assumptions above are correct and additionally you don't really know what those settings mean or what to do with them on the TIME/DIV controls for channels 1 & 2, they control how far zoomed in or out you are in the vertical or 'Y' axis of the scope display for the respective channel. Oscilloscopes do many things for us. Two of the main ones are they 1. allow us to SEE electricity...visualize the electrical waveform, and 2. to MEASURE the overall waveform...the amplitude and frequency. Again, an oscilloscope can do many, many more things, but for guys like you and me its often about amplitude and frequency, sometimes visualizing distortion, and also setting azimuth in X-Y mode. Okay...back on track.
Notice the scope display has a grid...so when you have the vertical axis set at 5mV, that means each mark or "division" (i.e. DIV) of the grid represents 5mV...volts per division (VOLTS/DIV)...if your waveform measures 7 divisions from peak-to-peak (in other wirds from the lowest point in the wave to the highest point), the voltage of the source is 7 x 5mV = 35mV. The ability to do the math of taking your vertical axis control setting and comparing the waveform to the divisions on the scope display only holds true if the channel is in the CAL position (CAL control usually rotated fully clockwise and usally there is a click or detent when the control is set to CAL). If the waveform is too big to see on the display, you're zoomed in too far...DON'T DICKER WITH THE CAL CONTROL TO REMEDY THIS. Just...zoom out a click on the VOLTS/DIV control..or two clicks...or whatever you need to do to see the whole waveform...and the opposite is true...if you can just barely see anything more than a flat line of a source signal you know is AC, zoom in. But do it with the VOLTS/DIV control and not the CAL control, because that way you can alway do the math and measure...or the guy on the forum can do the math...because we are trying to determine if your +30V supply has a problem...we are trying to verify whether or not AC ripple at the output of DC power supply's primary filter cap is in an order of magnitude of volts...which is bad, because it should be millivolts...if you get a waveform triggered on your display and were trying to quanitfy the amplitude, but you pull the channel out of the CAL setting, now its impossible to quantify the voltage of the waveform because we can no longer do the math.
And ahead of that the other thing we're trying to do first is to determine if your scope is displaying correctly. A known square wave signal is present at the calibration lug, okay? You probe that and your scope should display a square wave. So what? We don't stop there...we need to set our vertical axis and horizontal axis in a way that we can see the entire waveform, look at the vertical and horizontal control settings, do the math, and compare to the specifications of the calinration signal. We already know the voltage right? I stated it in a previous post because its printed right on the face of your scope...0.5V right? Now I want you to look in your manual...in the section where all the controls are numbered and then there is a list describing each control or facet...the frequency is noted there...find that and post it here. Once you have that information, probe the calibration lug again, set your vertical VOLTS/DIV control so you can see the whole waveform from top to bottom, and zoom in so the waveform takes up most of the vertical axis...maximizing the resolution gives a more accurate count of the divisions...then look at where the VOLTS/DIV control is set, and do the math after you count the divisions spanned by the waveform. And then adjust your TIME/DIV control, which is the horizontal axis, zoom that in so you see just one complete wave on the display...look at the TIME/DIV control at what the time per division is, and do the math after you count the divisions for the complete waveform (and for a square wave that's from the beginning of the top to the end of the bottom), which will give how many milli or micro seconds the wave is, and you can convert to Hz or kHz...if you don't know how to do that just say so and I'll help. Once we have all that math done we can compare what we measure on the display and compare to what its supposed to be coming off the calibration lug. With that we know if your scope is measuring and displaying accurately. THEN we can start looking at your power supply output.
The other pics are at the cap again...
"The cap..." The primary filter cap C609?
Pic 1 is at 2V, nothing changed except Voltage setting switch.
What is at 2V? The vertical axis VOLTS/DIV control on the scope? And I have no idea what voltage setting switch you are talking about.
Pic 2 is at .2V, but with the pot rolled back to about 9:00, which is the only way I could get waveform to show up at that setting.
Again, what is 0.2V? The VOLTS/DIV control? And "the pot..." are you talking about the CAL control?
Pic three is 5V, again with the pot all the way to the right,
Same questions as above.
Question for you:
The horizontal bank of switches on your scope at the top of and in betweem the channel 1 and channel 2 vertical axis controls...those mode switches labeled CH1, ADD and CH2...in the pics you posted which switch or switches are latched?