So I’ve run into a couple of problems, while trying for test the voltage change I got really weird results the Oscilloscope not being able to trigger and acting really weird then I noticed a slight tingle in my arm as I rested it on the chassis ground of the amp. I thought that was weird so decided to measure the voltage of chassis ground to my oscilloscope earth ground, I did this as the oscilloscope has a 3 prong plug and the amp has a 2 prong plug. Well I don’t know if this is normal or if I have a death machine on my hands and dodged a bullet the chassis of the amp is measuring 220VAC to earth ground. And that’s why I think it was giving me weird results, I think I need to ground the probe to earth ground from the oscilloscope because the amp isn’t grounded.
Usually non grounded/earthed cases can have some voltage measured against earth, this voltage have capacitance origin. It means voltage is coming to case thru capacitors or parasitic capacitances and it is not a problem, if device is connected to other devices this voltage is grounded and currents are very small. But it can be problem when connecting devices together when devices are powered on at the connecting moment, then some sensitive non protected devices can be killed.
Great! That's a relief.
I'll see what i can do about the sketchy readouts im getting with the oscilloscope right now.
I'll see what i can do about the sketchy readouts im getting with the oscilloscope right now.
I'm so confused, I've tried searching this problem up and I can't find anything. The probe is grounded to chassis of amp. I've tried messing around with the triggering modes and so on, timing and I just can't trigger it and the signal seems very random and unequal. I hope this video helps.
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Probably it is random noise with low frequency oscillation. When A was 0.1s, something understandable was seen, but amplitude was bigger than fit to screen.
What synchronization options this oscilloscope have? Maybe some other types give more stable image?
What synchronization options this oscilloscope have? Maybe some other types give more stable image?
what do you think the next procedure should be?
I’m thinking measuring at 0.1s and with bigger amplitude, then trying to trace it back.
I’m thinking measuring at 0.1s and with bigger amplitude, then trying to trace it back.
Try to find out, is signal amplitude you get with oscilloscope close to maximum you get with multimeter.
Yep the max I get on my DMM is the same as I get on the oscilloscope. With the very occasional spike above 0.5V
DMM:
Alright so the max of O/P with DMM is around .512VDC with occasional spike of around 1.3VDC
Pin 6 around 1.1Volts max stays around that higher .700VDc
Oscilloscope
O/P: oscillates up to circa 14VDC oscillation
Pin 6:around 12VDC oscillation
There might be some funky settings on my oscilloscope with 10x magnification or on my probe but on my probe it’s set to 1x and on my oscilloscope the 10x mag button is unpressed. And I also can’t stress the fact that the signal is very unstable.
Alright so the max of O/P with DMM is around .512VDC with occasional spike of around 1.3VDC
Pin 6 around 1.1Volts max stays around that higher .700VDc
Oscilloscope
O/P: oscillates up to circa 14VDC oscillation
Pin 6:around 12VDC oscillation
There might be some funky settings on my oscilloscope with 10x magnification or on my probe but on my probe it’s set to 1x and on my oscilloscope the 10x mag button is unpressed. And I also can’t stress the fact that the signal is very unstable.
This are very conflicting results.
Between IC201 pin 6 and O/P terminal is 2.2 M resistor and generally oscilloscope input resistance is 1 M ohms (Hitachi v-1065c have also), so it must divide voltage down about 3 times.
Also signal with 14 V amplitude cannot cause protection to turn on. My 216 will give out nearly 40V RMS - about 56V in amplitude before protection is turned on.
Try to measure some known 50 Hz AC voltage with oscilloscope and compare it to DMM AC voltage.
Or even better, test it on oscilloscope Probe adjust output what is 0.5V 1 kHz square wave.
Between IC201 pin 6 and O/P terminal is 2.2 M resistor and generally oscilloscope input resistance is 1 M ohms (Hitachi v-1065c have also), so it must divide voltage down about 3 times.
Also signal with 14 V amplitude cannot cause protection to turn on. My 216 will give out nearly 40V RMS - about 56V in amplitude before protection is turned on.
Try to measure some known 50 Hz AC voltage with oscilloscope and compare it to DMM AC voltage.
Or even better, test it on oscilloscope Probe adjust output what is 0.5V 1 kHz square wave.
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I have also made a video of my procedure of testing, although I feel like I’m doing everything right, I’m not sure. This is just an additional video if you think the problem is in my way of testing. I hope this helps
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Hard to understand all details, 2 photos can be better than 7 minute video.
Probably you had grounding issue when measuring, results are largely random, connection to case is not very reliable.
Had you tested your oscilloscope on Probe adjust output? Is oscilloscope working OK and setting are suitable?
Can you measure with oscilloscope when channel 1 is connected to O/P and Channel 2 to pin 6 of IC201? It is good to solder some small wires to this points (or to resistors R113 pin 6 side) so connection can be made with hawk/clip.
Probably you had grounding issue when measuring, results are largely random, connection to case is not very reliable.
Had you tested your oscilloscope on Probe adjust output? Is oscilloscope working OK and setting are suitable?
Can you measure with oscilloscope when channel 1 is connected to O/P and Channel 2 to pin 6 of IC201? It is good to solder some small wires to this points (or to resistors R113 pin 6 side) so connection can be made with hawk/clip.
The oscilloscope is in working condition the probe is calibrated very accurately too and displays a beautiful sine wave when hooked up to my phone with a frequency generator.
Sure, no problem. I made a video showcasing the results. The top signal "CH1" Is O/P. The bottom signal "CH2" is Pin 6. I move the signals to the middle to compare them at around 1:00
Now it is little better seen that O/P signal is sometimes very big and probably also DC is on output.
Had you checked JP201/JP31 plug, had it normal contact? If you measure resistance from R301 to R107.
Had you checked JP201/JP31 plug, had it normal contact? If you measure resistance from R301 to R107.