New Rigol dho804 oscillocope

I use  the power adaptor provided in the accessories box and I connect it to the AC power source (220 V, 50 Hz ).

So what is the right power adapter for this model Rigol  dho804   12V 4 A Or 15V 3A ?

The document you uploaded above, says  DC, 12 V, 4 A every time

Yes, so do you think it's largely a charger voltage issue?

I don't know. But if the power supply can deliver 75% of the required power, it's hard to validate if it is anything else...

It could be that Rigol re-designed the power requirements.  Certainly the newer version of the manual calls for 15V 3A.  I wouldn't plug anything in without checking with Rigol first what the specific instance based on serial number requires.

Ok, Thank you very much, I should contact Rigol service  to know if the power adapter came with scope is a correct or not.

(Yes), and give them a photo of the error, and how long it takes from powering on to the error

I mean: no, contact the vendor. Rigol will most likely ask you to do that anyway

Yes, I understand the difference here.  My point is that there seems to be a (perhaps older) version requiring a 12V 4a PD3 power supply and a newer version requiring a 15v 3A PD3 power supply.  The OP seems to have the latter supply but possibly a former instrument but it isn’t wholly clear: perhaps there is an unrelated fault (maybe using a 15v supply for a 12v instrument caused a problem), perhaps the PSU is wrong.  Is he reading the wrong version of the manual??  I wouldn’t be plugging any old supply into an instrument that is new and under warranty.

anniel747  I have original  power adapter for Toshiba laptop 15V 5 A , Can I try to connect it to scope.

anniel747  I have original  power adapter for Toshiba laptop 15V 5 A , Can I try to connect it to scope.

Well, maybe you should take a multimeter and check the polarity of both power adapters at the output connector.
Of course, the decent instrument should have a polarity protection at the input, but at modern times, nobody can be sure, because the cutting of costs. 

No.  You already have a 15v 3A supply but something isn’t working properly.  You may need a 12v 4a supply but it must be a USB-C PD3 supply as the scope will tell the power supply what it needs.  Don’t just plug any old supply into it: go back to your seller and tell them it doesn’t work

The main question is, what is the power input on his scope. Is it USB-C or a circular bayonet connector ?
Can the OP post a photo of the power input on his scope ?

It’s USB-C

OK, than you need an USB-C power supply.
In this case, I do not understand the photo, which Jan Cumps posted couple of hours ago - https://www.eevblog.com/forum/testgear/rigols-new-dho800-oscilloscope-unbox-teardown/msg4965181/#msg4965181

where at the adapter is clearly indicated as a the circular bayonet connector with + inside and - outside.

But, I am almost sure, that the power source is not a problem. If the scope is able to display a Rigol logo for five minutes and do a restart after that a go to loop, it really looks like a firmware problem.

PavelKCZ  Can I do something to reset firmware before start up operation? To make sure it's not a charger problem.

Yeh, that’s confusing: the referenced PSU has a circular connector according to the datasheet, but the text with that message implies it has USB-C and same poster’s picture of the back of his scope shows a USB-C socket.

I would not recommend any reset or any similar operation.
If the instrument is under the warranty, the only proper way is to contact the vendor and ask for exchange for working instrument or money back.

PavelKCZ You are right , the cost of purchase, shipping and taxes was exorbitant, about $500.