New Rigol dho804 oscillocope

Check the power supply - is it providing the right voltage to the main controller card?

Hello. Thank you for reply, I use the attached power supply 

I read this manual

Here's the same table from the manual I found: 

The newer dated manual, from their website, has the table I show below.  If your instance requires 12V 4A then you have the wrong power supply.  I suggest that you check with Rigol customer support.  Did you buy it from them?

I upload the DHO800_UserGuide_EN manual, This power supply has Type C terminal.

I bought it from local China supplier, You recommend me to change the power supply with another has 15v 4 A and test?

Looks like they gave you a wrong one. This is shown in an unboxing blog:

source: https://www.eevblog.com/forum/testgear/rigols-new-dho800-oscilloscope-unbox-teardown/msg4965181/#msg4965181

I saw a different one in a different unboxing video!!  

I would only recommend going back to the supplier or checking with Rigol support what power supply it should have based on the serial number.  If it really does require 12V you don't want to plug a 15V supply in.

I've seen 2 unboxings with that one

https://www.bilibili.com/video/BV1ox4y1R7qj/

https://www.bilibili.com/video/BV1Lz4y1E7bt/

There may be different versions out there. Did the one you see, have a good enough clarity to read the current? 

If you have a proper connector somewhere, you can solder a piece of wire to it, connect to your bench power supply and try it. If it will work, the AC adapter is faulty. If it will not work, something inside the scope is faulty. One way or another, you should ask the vendor for exchange for a working unit or money back.

If you have a proper connector somewhere, you can solder a piece of wire to it, connect to your bench power supply and try it. If it will work, the AC adapter is faulty. If it will not work, something inside the scope is faulty. One way or another, you should ask the vendor for exchange for a working unit or money back.