Rigol's New DHO800 Oscilloscope unbox & teardown

[Soundproofskin]

This won't earn any safety certificates, but it works

The ground pin on the French outlet is pretty chunky, I don't think a gator clip would hold on to it very securely. Did you cut the lead that came with the Rigol and replace one end with the gator clip?

If I do cut the lead I think I may try hooking it up to the earth of an actual plug, as Norbert suggested, and removing the other pins. But I'm a bit reluctant to destroy this lead since there's only one.

[Fungus]

This won't earn any safety certificates, but it works:

Maybe not the best implementation but that pic contains all the information needed.

[Fungus]

If I do cut the lead I think I may try hooking it up to the earth of an actual plug, as Norbert suggested, and removing the other pins. But I'm a bit reluctant to destroy this lead since there's only one.

No need to cut it. Get a female banana socket and bring a wire from the plug to your workbench. The Rigol lead is quite short anyway.

Or ... get a male banana plug and make your own earth lead. Save the Rigol one.

[norbert.kiszka]

Real socket plug is good enough. It's also possible to change plug from PSU, to add second wire/cable. Supplied cable with PSU is most likely 3x0.75 or 2x0.75 so it's thin enough to have space inside most of the plugs.

[shapirus]

No need to cut it. Get a female banana socket and bring a wire from the plug to your workbench. The Rigol lead is quite short anyway.

That's precisely what I did.

A better way would be to get a male mains plug, leave the live and neutral pins unconnected (or, better, remove them altogether, if the body of the plug will still hold in the outlet reliably, or replace with a suitable diameter plastic rods) and connect a wire to the earth pin.

[norbert.kiszka]

Other side You need to connect into PE (ground) from Your installation (most likely from wall socket).

Would you know if there is any kind of adapter that allows one to insert the earth lead into the ground of an EU/French outlet? The earth on an French outlet is a male pin, so there's no way of them connecting without some sort of adapter.

This won't earn any safety certificates, but it works:

(Attachment Link)

BTW is that a metal dust that went into socket? In that case You should change that socket into at least IP44 (better protection from dust and water than IP20 which You have on this photo) - in easiest words, it's a socket with a cover on hinges.

Otherwise it can compromise connection (fire in case of more current like couple ampers literally - don't ask me how I know) and since it's metal, it can accumulate inside and behave like overpowered heater, which also can cause fire to start.

Example IP44 socket looks like this:

[Soundproofskin]

Thanks for the help everyone.

[Hix]

Do you have a link for Dave's DHO814.bin please? I have a new 814 that has stopped booting and I want to try to restore it without having to ship back to CN at my own expense

[Fungus]

Do you have a link for Dave's DHO814.bin please? I have a new 814 that has stopped booting and I want to try to restore it without having to ship back to CN at my own expense

See the first few posts in this thread: https://www.eevblog.com/forum/testgear/hacking-the-rigol-dho800900-scope/

[Hix]

May I ask how you know this, and if there is a fix? It could have been something I inadvertently have done, not knowing what I was doing

Warning: Do NOT switch the 'scope off in XY mode if you've installed firmware 1.03.

It won't boot again if you do.

(I recommend downgrading to 1.02 until they fix it)

[Fungus]

May I ask how you know this

Guess...?

if there is a fix?

No.

[dzwer]

Has anyone used a linear power supply to power any of DHO800/900 oscilloscopes?
Does it make sense to use such a power supply at all?
In the User's Manual it is listed as 15V and 3A max consumption.

[Fungus]

Has anyone used a linear power supply to power any of DHO800/900 oscilloscopes?
Does it make sense to use such a power supply at all?
In the User's Manual it is listed as 15V and 3A max consumption.

It doesn't make any sense. The thing's full of buck converters to drop the input voltage to the levels it needs internally. They obviously included enough filtering.

[norbert.kiszka]

They obviously included enough filtering.

Not so much. Compare DHO4000 with other DHO. This first one has low noise LDO for AFE and because of that, it can go over 800 MHz with even less noise, but with same AFE and same ADC.

[eTobey]

They obviously included enough filtering.

Where do you see the "obvious"? I found the external supply to bring in a bit of noise. A ferrit and some tinfoil helped...

[norbert.kiszka]

They obviously included enough filtering.

Where do you see the "obvious"? I found the external supply to bring in a bit of noise. A ferrit and some tinfoil helped...

I think, he is the main troll of this forum. Not first time, when he wrote something "wise" like that. Quick look into inside of this scope, and it's obvious it was made to be cheap as possible, including lack of power supply filtering.

[Fungus]

They obviously included enough filtering.

Where do you see the "obvious"? I found the external supply to bring in a bit of noise. A ferrit and some tinfoil helped...

Mine's down near 60uV.

[dzwer]

Another solution is to cut the PSU cable just before the USB-C connector and to place a CLC filter there.

[AndyBig]

Where do you see the "obvious"? I found the external supply to bring in a bit of noise. A ferrit and some tinfoil helped...

Here are two pairs of screenshots of the oscilloscope's own noise measurements. The first channel is noisier because its bandwidth is extended to 420 MHz.
Try to determine which pair was taken with the original power supply, and which with the laboratory linear one.

[dzwer]

Which PSU do you have?
Lenovo or Delta?
My DHO804 came with Delta 65W power adapter.

[AndyBig]

Which PSU do you have?
Lenovo or Delta?
My DHO804 came with Delta 65W power adapter.

Mine came with Liteon

[metrologist]

Is there really a difference that's not just lost in the noise?

[Fungus]

Is there really a difference that's not just lost in the noise?

No.

As noted earlier, this isn't a 12V device. The first thing that happens to the 12V input is that it'll go through a buck converter... any advantage is lost right there.

[vik-lob]

Hello. I have a question: when viewing the board sensors, the SPU MGTAVIT reading is highlighted in red and equals 1.23v. How critical is this?

[norbert.kiszka]

Hello. I have a question: when viewing the board sensors, the SPU MGTAVIT reading is highlighted in red and equals 1.23v. How critical is this?

Something can overheat and fail after some time. Nothing to worry about For real, do You have warranty?