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Hello guys!
I bought an Hantek DSO4072C Oscilloscope but shortly it burned out.
I connected the probes to the front calibration port (5v@1khz) and the scope behaved like this:
![](https://s19.postimg.cc/hzhd6f9oj/pic_39_3.gif)
![](https://s19.postimg.cc/lvup2emyb/pic_38_2.gif)
Then, I found the channel input schematics here in this forum that I want to thank to the author (DSO 5000 series).
Looking in another forum from Hantek support I saw someone with similar problem, then I replace the transistors/diodes of each channel:
![](https://s19.postimg.cc/cmnxejweb/5sot23.jpg)
BAV99 (marked A7), MMBTH10 (marked 3EM), MMBF4393 (Marked 6G) and the 2 x BC846B (marked 1B)
Then the signal has stabilized but came another headache:
![](https://s19.postimg.cc/6yhmnsa37/pic_50_6.gif)
![](https://s19.postimg.cc/lug5ve8n7/pic_50_8.gif)
Peak to Peak voltage and the waveform amplitude decreases as I move the trace down (Vertical position), and I cant move down from the center of the screen, both channels behave the same way.
I have a second oscilloscope (analog) and I can perform some measurements, but unfortunately my knowledge is limited.
Anyone can help me, please?
Thank you all.