So what is happening here? We have a real mystery.
..
A hardware issue? Some difference at the component level somehow?
My friend You may not be too far from the truth.
What is happening is very simple and I have been saying this for months:
Rigol have no idea what they are doingThis was proved in another thread for their bad oscilloscope ADC clock case. It was clear they had no idea how the circuit works, how to select design parameters, how to select components, how to layout the circuit. No quality control was performed, otherwise this defect would have been caught right away.
I myself have a DS2072 and it caused me direct dollar loss in terms of my lost time before I realized what rubbish it was. It only took me less than 24 hours to be hit with at least two defects - lock ups and that the scope did not memorize its 50 Ohm input setting between power-ups. You check the setting in the menu and it says it was on 50 Ohm, where is in fact the input was on high impedance. That mislead me and caused me wasted time which cost money. There is no excuse for this type of shit to be happening.
I bought 2072a scope to make my life easier, but it made my life harder. I have been saying since then anyone buying rigol junk will sooner or later regret they did. Reading this and other threads I can see it is now happening that this junk began affecting their owner's performance. Why do you, I and others have to spend time fighting with this POS instead of using this time for their circuit testing. What kind of instrument is it if it requires fixing it first. Oh year, I can already hear someone singing the familiar "cheap, best bung for the buck !!" mantra. But is it? Cant you guys see that you now waste your time troubleshooting this shit? Is that what "best bang for the buck" supposed to look like ?
In regards to your hardware issue guess, it well may be the case. I have opened my 2072a to fix the ADC clock problem and what I found beside that problem was bunch of other hardware related problems all over the board, along and across. In one instance reviewing a circuit that occupied 1 square inch of space on the PCB I counted 10 design errors! Wrong component selection, wrong design, wrong circuit layout. 10 errors per sq inch, that tells me something. And that is:
- No more rigol shit of any kind on my bench. Never again.