Seamus Brokaw

My mistake I misread your title and was referencing MDO3000 support docs. The DPO3000 is a different instrument and has its own firmware and documentation. The service manual shows several adjustments available on the DPO3k including DC Voltage that the cal lab probably performed.

The most recent firmware is v2.40 released 6/20/2012. Could you try updating that? This instrument ended long term support in 2018 so it may be difficult to find parts if we discover its a hardware issue.

Hello,<br> <br> Does the MDO's Self Test utility report any failures? <ol> <li>Push Utility</li> <li>Push Utility Page and then select Self Test</li> <li>Push OK Run Self Test</li> </ol> <br> I agree with Jacob my first thought was, "what is different between your house and the cal lab?" and that made me think about Line Power. Power Supply problems can manifest with strange symptoms. Another possibility is that the channel shows some offset drift only when the channel is open. Put a short or 50Ohm term on the channel and run AutoZero. AutoZero may remove that DC drift. It wouldn't, however, explain why SPC was failing. SPC is designed to run with the channels disconnected and open.<br> <br> I'm also curious what the cal lab adjusted. Our <a href="https://www.tek.com/en/manual/oscilloscope/mdo3000-service-manual-mdo3000">service manual</a> does not publish any adjustments that can be made by 3rd party cal labs. A Tek Service center would have much better diagnostic and repair capability.<br> <br> Sorry I don't have a guaranteed solution at this point.<br> <br> &nbsp;