EEVblog #1146 - New Low Cost Rigol MSO5000 Oscilloscope

[Martin72]

You open it up, change the hardware - and warranty remains.
You modify the booting with all options including, everytime reversible - and warranty will void.
Interesting…

[tv84]

Interesting…

It's called soft void. The other is hard void. 

[alexvg]

1. After hacking the device, the warranty is void.
2. After opening the device, the warranty is void.
3. After modifying the device, the warranty is void.
I've done all 3.
Lot's of people have only done the first one.
(Using a non-Rigol MSO5000 Logic Analyser Probe will void the warranty ? https://www.eevblog.com/forum/testgear/rpl1116-active-logic-probe-pod-for-1000z-series-teardown/ )

In case of warranty needs :
I could totaly restore the device hardware without beeing detected.
But I don't know if a firmware restoration could be possible without beeing detected.

My goal is to provide a better longevity to this device.
The low quality power supply capacitors and all temperatures too high weak the device and reduce its life.

[alexvg]

4-pins power supply connector

Code: [Select]

+7V_A ... Black
GND ..... not used
GND ..... Black
+9V ..... Green


6-pins power supply connector

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+7V_B ... Black
-7V ..... Purple
GND ..... Blue
GND ..... Black
+5V ..... Yellow
+5V ..... Red

"+7V_A" and "+7V_B" are differents.
The 2 pins "+5V" are the same.
"+9V" is send to the fan throught a measured resistance of 36.5R

The rear panel without the original fan and its metal part.

[Martin72]

But I don't know if a firmware restoration could be possible without beeing detected.

Hm-Hm...

Maybe this :

https://www.eevblog.com/forum/testgear/review-rigol-mso5000-tests-bugs-questions/msg2521134/#msg2521134

Have provide me....

[nimish]

1. After hacking the device, the warranty is void.
2. After opening the device, the warranty is void.
3. After modifying the device, the warranty is void.
I've done all 3.
Lot's of people have only done the first one.
(Using a non-Rigol MSO5000 Logic Analyser Probe will void the warranty ? https://www.eevblog.com/forum/testgear/rpl1116-active-logic-probe-pod-for-1000z-series-teardown/ )

In case of warranty needs :
I could totaly restore the device hardware without beeing detected.
But I don't know if a firmware restoration could be possible without beeing detected.

My goal is to provide a better longevity to this device.
The low quality power supply capacitors and all temperatures too high weak the device and reduce its life.

FYI: Magnuson-Moss in the US prevents 1,2,3 from being used against you unless Rigol can prove your mods caused the issue.

Not that Rigol is whom you should go with for warranty support or support in general, but the law is on the consumer side here.

[nimish]

But I don't know if a firmware restoration could be possible without beeing detected.

Hm-Hm...

Maybe this :

https://www.eevblog.com/forum/testgear/review-rigol-mso5000-tests-bugs-questions/msg2521134/#msg2521134

Have provide me....

Connecting a scope to the internet is a fantastically stupid idea, given that these products are not built by people with any real software experience. Just d/l the firmware and flash upgrade via a USB stick. I wouldn't be surprised if someone found a RCE vuln that could literally destroy the scope by messing with HW params set in software.

[Martin72]

Connecting a scope to the internet is a fantastically stupid idea, given that these products are not built by people with any real software experience.

But obviously they did it.
Stupid People who could design a scope.

[Mr. Scram]

Connecting a scope to the internet is a fantastically stupid idea, given that these products are not built by people with any real software experience. Just d/l the firmware and flash upgrade via a USB stick. I wouldn't be surprised if someone found a RCE vuln that could literally destroy the scope by messing with HW params set in software.

It's an IoT device, except that it's a precision instrument and over 1K euro. What could possibly go wrong?

[alexvg]

FYI: Magnuson-Moss in the US prevents 1,2,3 from being used against you unless Rigol can prove your mods caused the issue.

Not that Rigol is whom you should go with for warranty support or support in general, but the law is on the consumer side here.

Thanks for these informations.

[Martin72]

Could you take a photo from the lcd-display, the backside ?

[alexvg]

Could you take a photo from the lcd-display, the backside ?

I do not want to completely dismantle the device to take this photo.

[alexvg]

Here is the heat sources.


The airflow through LA connector is very hot due to high heat sources proximity.

The Rigol cooling system just stirs up the air.

update:
After restored the original cooling system... I'm trying multiple solutions to improve cooling without any success : too noisy or not enough efficient.
Original 80x80x25mm Sunon fan to mainboard.
Added 120x120x15 Noctua NF-A12x15 FLX fan to 9V from power supply

Results @ ambiant 25C
Right side of LA connector (hottest pin) : 50C
Hottest BNC (GI connector) : 38C

But noise is too high...






Now I'm going to reverse the flow of the original fan and do multiple tests...

[alexvg]

I've just inverted the airflow of the 2 fans, the result is worst.
But if I had the skirt to the 80x80x25 Sunon fan, the result is very good : LA connector is 44C and BNC is 39C. Noise is a bit lower. Ambiant is 25C.
With the Sunon and Noctua at 9V, the Noise is higher but LA connector is 41C and BNC is 36C.

Conclusion : The original 80x80x25 Sunon fan is definitely not a good idea.

Now I'm going to test again the original configuration to have more temperature values.

[alexvg]

I've finished doing all temperature measurements with original fan configuration...

[rsjsouza]

68°C on those poor devices?!? Wow... Just... Wow...

The ADC at 51°C is at that level probably because of its surroundings

[alexvg]

The hottest point (68C) seems to be voltage regulators :

[Martin72]

68°C on those poor devices?!?

Nothing uncommon for voltage regulators without explicit heatsinks.

[rsjsouza]

68°C on those poor devices?!?

Nothing uncommon for voltage regulators without explicit heatsinks.

The temperature is terrible if the part is rated for commercial use at 70°C - something hard to see from the then published photo.

Voltage regulators don't carry "explicit heatsinks" but properly sized PCB ground planes soldered to their Thermal pads instead.

P.S. The part is a TPS7A33, which is rated for 125°C, so it is ok for the part itself, but still not great for the overall system due to the temperature differences caused between the channels. But I grant this is par for the course of such integrated device.

[nctnico]

Where these measurements done using black non-reflective spots (black paper stickers for example)? Otherwise the temperatures will be way off due to reflections and different emissivities.

[thm_w]

The temperature is terrible if the part is rated for commercial use at 70°C - something hard to see from the then published photo.

Voltage regulators don't carry "explicit heatsinks" but properly sized PCB ground planes soldered to their Thermal pads instead.

P.S. The part is a TPS7A33, which is rated for 125°C, so it is ok for the part itself, but still not great for the overall system due to the temperature differences caused between the channels. But I grant this is par for the course of such integrated device.

0 to 50C is the rated operating temperature.
43C over ambient so maybe 93C at 50C ambient.

TPS7A33 is rated 125C junction, but you have to take into account junction to case rating (30 C per Watt) as well.

[Martin72]

Voltage regulators don't carry "explicit heatsinks" but properly sized PCB ground planes soldered to their Thermal pads instead.

Oh really, and I thought they´re hanging in the air. 

Where these measurements done using black non-reflective spots (black paper stickers for example)? Otherwise the temperatures will be way off due to reflections and different emissivities.

I´m thinking about a "classical" measurement with K-Type sensors but at home I couldn´t measure more than 2 points at the same time.
At work we got a yokogawa 16-channel device..
By the way, my question about the decreased fan power and if they (rigol) got it in mind what heating up the enviroment concerns due to this wouldn´t be answered until now, very uncommon.

The Rigol cooling system just stirs up the air.

Yepp, today I got mine opening too to look what they´ve changed :

https://www.eevblog.com/forum/testgear/rigol-mso-5000-hardwaresoftware-revisions/msg2550510/#msg2550510

[alexvg]

I´m thinking about a "classical" measurement with K-Type sensors but at home I couldn´t measure more than 2 points at the same time.
At work we got a yokogawa 16-channel device..

I have multiple K-type thermocouples and I could measure 4 temperatures at once (with around 1-2C precision between them - I've checked 3 temperatures : -25C, ambiant and sun).
And the Flir could not be used... Dave already used Flir over the PCB.

By the way, my question about the decreased fan power and if they (rigol) got it in mind what heating up the enviroment concerns due to this wouldn´t be answered until now, very uncommon.

The Rigol cooling system just stirs up the air.

I think using this current (stir up the air) system will reduce the lifetime. Is it a choice or a drawback to a less-noisy device ?

Yepp, today I got mine opening too to look what they´ve changed :

I've got the same revision (I've removed properly the Rigol warranty sticker...).

I'm going to try a 90mm Noctua fan... I wish to propose a solution not requiring to remove the 4 rivets and the metal support of the fan.

[alexvg]

I've found a solution, here's the result (ambiant 25C - after 1h warm-up) :
- 50C @ internal regulator (18C lower)
- 40C @ hottest analog front-end channel (6C to 11C lower)
- 34C @ LA connector (22C lower)
- 34C @ hottest BNC connector (4C to 5C lower)
- The noise level is correct (same level as Siglent SDM3055)

Simple description (pictures come later) for this first modification "MSO5000_cooling_mod_a"
- You need to remove the metal protection panel
- Replace the original Sunon fan with a Noctua NF-A9 5V and mount with output airflow upside
- Create an airduct adapter to convert the original 80mm hole and screw holes to the new 92mm Noctua fan (height does not exceed 8mm)
- Pick the 5V on red wire from power supply and ground from hearth screw to the new Noctua fan (warning !!! 5V only !)
- Attach another Noctua NF-A12x15 FLX fan to the back-panel (airflow will come in), it will be over the power-supply
- Make a converter from the original Rigol 2-pin fan connector to a classical 3-pin fan connector and connect the new 120mm Noctua fan (after checking the ground to earth and +V to the green wire)
- Install the specific skirt (I'll post pictures and schematic later)

Pro :
- Not necessary to remove original metal fan-frame and the 4 rivets
- Temperatures are far below from the original design

Cons :
- Need to open the unit and remove the internal metal protection panel
- Noise is a little higher
- Need to buy 2 fans (Noctua NF-A9 5V and Noctua NF-A12x15 FLX)
- Need to create a 80 to 92mm airduct adapter with a small height (8mm)
- Attaching the 120mm fan to the back side of the box could be complicated


Airduct adapter 80 to 92mm fan using cardboard


Airduct schematic using 80-300g/m2 paper (.1mm = 1pixel)
 airduct-92mm-paper-cut.png (19.98 kB. 2000x2000 - viewed 338 times.)

[alexvg]

To lower the noise, I've done 2 modifications :
- I've removed the connection to the mainboard power supply fan connector. I've added a 50R resistor to the Noctua 120mm fan to the +9V from the power supply. You also could use the mainboard fan connector with a 12R resistor.
- I've added a 1N4007 diode to the Noctua 92mm 5V fan.

The global noise level is the same as the original Sunon fan.
I'm waiting for the temperature results...

update

Temperature results (original Rigol cooling/previous test/current test) :

Code: [Select]

internal regulator                 68C / 50C / 51C
hottest analog front-end channel   51C / 40C / 42C
LA connector                       56C / 34C / 41C
hottest BNC connector              39C / 34C / 37C