Rigol's New DHO800 Oscilloscope unbox & teardown

[Luc7777]

There are three posibilities, you have a special firmware, you don't touch slow enough on the screen or you touch in the wrong place.
https://photos.app.goo.gl/dHPxWyLqyN4hQU9c8

[dreamcat4]

ok but heres a silly question (its silly because it should not be necessary to resort to such elaborate methods...)

but if can attach the android adb (from another computer). and then launch the rigol andoid apk app. or vendor.bin whatever it is - instead of launching this binary executable in the normal fashoin. you could kill the running process instance. and prevent it from relaunching automatically...

then launch it manually yourself via the remote android adb debugger. this would then permit to pause and freeze the execution just before / after the touch event tapping the screen. to then use the step-thru and step-over (single step) debugging around that flashing of the screen.

and perhaps modify the settings value thru the android adb debugger.

but there could be much simpler and easier ways to modify the relevant setting directly. for example on the filesystem, or in the flash etc.

but another route is either file a bug report, asking rigol for a beta build with such fix in it. or alternatively do other things (which again, should be totally unnecessary or silly / too much work)

this is assuming that the observed behaviour is definately a bug in those firmware builds... or maybe it's actually a different type of bug. whereby your scope's own settings area has gotten corrupted. then the firmware is trying (correctly) to load or save those relevant settings page. but the action fails since that block or specific file of settings is in fact corrupt. which then is working fine on everybody else's scopes. (but that is just purely a speculation - i have no idea).

[EEVblog]

There are three posibilities, you have a special firmware, you don't touch slow enough on the screen or you touch in the wrong place.
https://photos.app.goo.gl/dHPxWyLqyN4hQU9c8

Thanks, that worked. I was hitting Other 3 times instead of About 

[Njk]

On every screenshot, the icon with styled R letter can be noticed in the bottom left corner. It's located in a place where it's hard to miss it. What is its purpose? Is it just a decoration or it bears some functional loading?

[skander36]

On every screenshot, the icon with styled R letter can be noticed in the bottom left corner. It's located in a place where it's hard to miss it. What is its purpose? Is it just a decoration or it bears some functional loading?

It's the Start Menu Icon ... as is in Windows 

[Fungus]

On every screenshot, the icon with styled R letter can be noticed in the bottom left corner. It's located in a place where it's hard to miss it. What is its purpose? Is it just a decoration or it bears some functional loading?

It opens the main menu.

[simone.pignatti]

On the bottom right side of the display there is a loudspeaker icon, depending on how you press it it turn audio ON and OFF or you access to the Utlity Menu.
By the way we tested the unit with a 72Wh power bank today and it lasted about 1.5hours.
We posted the video on YT.

[dreamcat4]

indeed that was estimated based on such high constant power. which seems to be about the same sort of 30w both idle and full load. maybe due to the complex powering requirements of the fpga.

anyhow so this is actually why i feel 2x makita 18v hotswap bays (switch over a/b) configuration is best. because it lets you then about 4h for the airline-flyable 5ah packs. (each of those being around 100wh give or take).

but you could then potentially design a scheme to hotswap without power loss. or any interruption, and either use bigger or smaller (being anywhere between 2ah-9ah packs). and then not loose your work when the battery inconveniently runs out at the most inorpportune moment halfway thru your work. you could even continuusly cycle the cell packs to a nearby charging station to. for untethered operations in awkward spaces. i.e. (for example) automotive work. or up at the top of an antennae towers. or whatever other variety of less convenient stationary on the spot locations. that cannot pickup move and take the dut back to lab / workshop.

[Veteran68]

On the bottom right side of the display there is a loudspeaker icon, depending on how you press it it turn audio ON and OFF or you access to the Utlity Menu.
By the way we tested the unit with a 72Wh power bank today and it lasted about 1.5hours.
We posted the video on YT.

Since you have the 924, have you been able to test maxing out the bandwidth to see how it performs? Or did I miss your report? There's lots of speculation (with good reason) that the sample rate can't support 250Mhz bandwidth without serious drawbacks, and I'm waiting for someone to weigh in on just how useful the 250Mhz bandwidth is in this scope. If it's entirely useable thanks to some magic sauce that Rigol has implemented, then I expect I may just spring for the 924S outright (despite its hackability, as the cost difference isn't enough for me to bother hacking it up). If however it's unusable or marginally so, I'll either wait for something better from Siglent, or satisfy myself with the 100Mhz model. No point spending the extra 100 bucks if it's not usable.

[hbozyq]

The offset issue seems like to firmware related. DHO804 with firmware version 00.01.00(2023/07/21) will suffer offset after replace vendor.bin, while 00.01.14(2023/07/06) wont.

It could be the way to selfcal between two versions are different. Maybe someone could upload a vendor.bin from DHO924 with new firmware and I will try it.

An other way is to replace SD image to downgrade fw version and simply fix it, but teardown is needed .

[Fungus]

There's lots of speculation (with good reason) that the sample rate can't support 250Mhz bandwidth without serious drawbacks, and I'm waiting for someone to weigh in on just how useful the 250Mhz bandwidth is in this scope.

The numbers don't add up with 4 channels enabled but it should be fine with only 1 or 2.

[Fungus]

The offset issue seems like to firmware related. DHO804 with firmware version 00.01.00(2023/07/21) will suffer offset after replace vendor.bin, while 00.01.14(2023/07/06) wont.

Apparently there's an extended calibration menu that can be enabled. Would that fix it?

(Maybe the "AFE zero" - I assume that's Analog Front End, but it ought to be doing that anyway)

It could be the way to selfcal between two versions are different.

Nah.

[rpro]

It could be that the different versions of the firmware are calibrating more or less items by default on that hidden menu.     

hubertyoung, can you please take a look at your hidden calibration menu (via pressing "About" 3 times in the "Utility" menu) and tell us what you see? Thanks.

[iMo]

.. and I'm waiting for someone to weigh in on just how useful the 250Mhz bandwidth is in this scope. ..

A suitable test scenario has to be created first.. E.g. how to measure "the sample rate vs. the BW" with 1 channel, 2 channels and 3/4 channels on - such we get some relevant results for each scope type/hack, ie. scope type original (with its hw revision, fw revision, etc.) vs. hacked scope type (with the fw revision, etc) - a table with numbers such the experts here may judge. Mind there are 70MHz models and 100MHz models which might be hacked to any other higher model. A detailed guide basically how to do it.. Otherwise we will still be speculating..

[Fungus]

Rigol are known for many things but lying about bandwidth isn't one of them

The manual for these even tells you there might be problems with 3/4 channels enabled.

A suitable test scenario has to be created first..

I'm not really worried about the claimed bandwidth but one thing that needs testing/characterizing is the probes that are supplied with the lower-spec models. There's no point enabling a 250Mhz front end if the probes aren't up to it.

(or maybe the probes will have a nice rolloff and help with the problem  )

[iMo]

Rigol are known for many things but lying about bandwidth isn't one of them

The manual for these even tells you there might be problems with 3/4 channels enabled.

A suitable test scenario has to be created first..

I'm not really worried about the claimed bandwidth but one thing that needs testing/characterizing is the probes that are supplied with the lower-spec models. There's no point enabling a 250Mhz front end if the probes aren't up to it.

(or maybe the probes will have a nice rolloff and help with the problem  )

There is an higher order LC low pass in the front of the ADC in all channels (in 800/900/1000 series I saw videos of). It could easily be the low-pass has been tuned for each type (based on the BW) a little bit differently. It is not about what Rigol says or usually does, but what you will be measuring in reality. Also the various revisions of hw and fw might come with changes. Thus either people want "to know", or "it does not matter" for them how their stuff works in this price range..

[hubertyoung]

The good news is that I used the first batch of DHO804 img image packages to write to the TF card and successfully started the machine. Although there is an offset, it disappears after calibration. Then I replaced vendor.bin with 924 successfully. And there is no offset, even when calibrating again.

Could you please post the image somewhere? Is there a way to write the TF card without taking the scope apart? Thanks a lot.

I haven't found anything that can be done without removing the TF card. But for fragile stickers, you can use an air gun to heat them at 100 degrees. Use a knife to remove without damage.

Thank you, would you be so kind to share the TF image file of the first batch 804?

the first batch 804, and 924 vendor.bin
https://mega.nz/file/06VDFaBI#3pmlujrkarmJ63_5Vh9VDz-VOt_nxBVmmBv0GXrSxZo

[TomKatt]

There is an higher order LC low pass in the front of the ADC in all channels (in 800/900/1000 series I saw videos of). It could easily be the low-pass has been tuned for each type (based on the BW) a little bit differently. It is not about what Rigol says or usually does, but what you will be measuring in reality. Also the various revisions of hw and fw might come with changes. Thus either people want "to know", or "it does not matter" for them how their stuff works in this price range..

Are you suggesting that possibly even if the FW could be hacked, there may be model specific hardware differences that might prevent a lower spec model from running at the full bandwidth of a higher spec model, even if the software was not aware of the difference and identified itself properly as a higher spec model?

[rpro]

I recall Azusa writing that the LC filters have a 300MHz cutoff.

[dreamcat4]

maybe they can afford to do something better factory calibration to the frontend? But is that really a thing here? (for these stages?)

[akkk44]

The good news is that I used the first batch of DHO804 img image packages to write to the TF card and successfully started the machine. Although there is an offset, it disappears after calibration. Then I replaced vendor.bin with 924 successfully. And there is no offset, even when calibrating again.

Could you please post the image somewhere? Is there a way to write the TF card without taking the scope apart? Thanks a lot.

I haven't found anything that can be done without removing the TF card. But for fragile stickers, you can use an air gun to heat them at 100 degrees. Use a knife to remove without damage.

Thank you, would you be so kind to share the TF image file of the first batch 804?

the first batch 804, and 924 vendor.bin
https://mega.nz/file/R7EgwSJC#FWBNraDHczaTwcVX_kuTKkTImUm37a1ZZnZf2uaGMHU

Many thanks

[jusaca]

On the bottom right side of the display there is a loudspeaker icon, depending on how you press it it turn audio ON and OFF or you access to the Utlity Menu.
[...]

Can it also turn off the noise of the fan?

[Fungus]

Are you suggesting that possibly even if the FW could be hacked, there may be model specific hardware differences that might prevent a lower spec model from running at the full bandwidth of a higher spec model

No.

People have already fiddled with the firmware and seen/measured 250Mhz on the lowest model (DHO804).

[Fungus]

I was just grepping the DHO800 firmware image uploaded earlier and the words "power analysis" are there in a few places. 

I wonder if it can be enabled.

[Fungus]

the first batch 804, and 924 vendor.bin

I assume they're encrypted or something because they're completely different inside.