REVIEW - Owon SDS7102 - A look at the SDS series from Owon

[rf-loop]

Do you have any measured data about "before" and "after".  What are measured improvements? (I mean raw measured data).

This method for fix metal plate where are input BNC. It is becouse service. This can take off with one nice wide heater. After soldering here and there it is not easy serviceable. (in factory routines).

Mechanic is designed so that if need take base plate out there no need take power board out.
Adapter board can move 5mm to under power board and it can take out from main board connector.
And whole baseplate can then lift off together leaving main board together with frontpanel board.
Now if have service cable between adapter board and main board it can power up for example front end capacitors adjusting or example change fan. (it need note: handle fan as very fragile! This fan model bearings damaged very easy  with extra force (fingers etc) when handling baseplate. 

On the adapter board is also backlight driver. Some versions have dim display becouse they have adjusted (with fixed resistor) this current too low. Nominan current for display LED backlight is 180mA. (current can measure without taking off LED connector. (but keep care do not force it under 5-6V when measure current. Use  example 7x1N4148 series with current meter) (measure current between connector... time when measure current go to meter and LED's shut off.
Typical value for R17 is 1R0 - 1R4
(do not make mistake if read value marked on resistor... sometimes they have soldered two resistors...)

250MHz SDS7102 (and 500MHz) SDS8xxx need reduce. It can do only changing ADC area on the board. (Grounding is not best possible, analog and digital ground HF separation lacks. This is my suspect, I do not first think it problem is on the RuiFeng ADC silicon)

[blueflash]

There are no measured improvements! This changes are not made because of known problems in signal integrity. It was only the wish to make it a little bit more perfect.
(I love it to disassamble devices and to make some changes on it...    )

You are right with the argument of making service a little bit more difficult. Also be aware that these changes may let You loose waranty!
So this changes are not a "must" but only a "nice to have" option and it is up to You if You want to make it.

Measurements from "before" You can see in the mikrocontroller thread. You will see that there is nothing to complain about the signal acquisition. What I didn't tried is to measure a small signal with VGA out switched on. Can anybody with a VGA out option check this? On my device there is no crosstalk fom VGA to ADC measurable.

[pofigist]

translator (English):
Hello. I'm on the fault of my oscilloscope described above.
Contacted OWON (China) , for me they are advised to update the software and sent to the firmware version 2.0.
Firmware problem is not resolved!
---
original text(Russian):
Zdravstvuyteyu Ya po povodu neispravnosti moego oscillografa opisannoy vysheyu
Svyazalsya s SchCSchT (Kitay)  mne oni posovetovali obnovit' programmnoe obespechenie i prislali proshivku versiey 2.0.
Proshivku problemu ne reshila!

[rf-loop]

translator (English):
Hello. I'm on the fault of my oscilloscope described above.
Contacted OWON (China) , for me they are advised to update the software and sent to the firmware version 2.0.
Firmware problem is not resolved!

What FW problem?

Before you have sent this message:
"Re: Review of Owon SDS7102
« Reply #373 on: November 13, 2011, 01:33:23 PM »
"

In this message you show problem.

It looks like HW problem as described before.
Where fromm you get opinion that it is FW problem.
I heve looked your videos and it is 99% sure HW manufacturing fail.
Contact to Owon china service  if your local  reseller do not understand anything.   You have faulty product what need repair or warranty exchange. This forum do not repair it.

[Muxa52]

translator (English):
Hello. I'm on the fault of my oscilloscope described above.
Contacted OWON (China) , for me they are advised to update the software and sent to the firmware version 2.0.
Firmware problem is not resolved!

What FW problem?

Before you have sent this message:
"Re: Review of Owon SDS7102
« Reply #373 on: November 13, 2011, 01:33:23 PM »
"

In this message you show problem.

It looks like HW problem as described before.
Where fromm you get opinion that it is FW problem.
I heve looked your videos and it is 99% sure HW manufacturing fail.
Contact to Owon china service  if your local  reseller do not understand anything.   You have faulty product what need repair or warranty exchange. This forum do not repair it.

I think also that is a defect in the soldering chips in BGA package. over time defect will increase only. repair requires specialized equipment and sufficient experience. You should seek a specialist or send DSO to manufacturer.

[rf-loop]

You should seek a specialist or send DSO to manufacturer.

In this case only acceptable specialist is Owon service. Local or manufacturer in China. Ask normal RMA process. 
This forum do not anything for repair it. Owon or first your local seller is right address. Owon is reputable company who have also warranty time repair system and just normal RMA handling process.  If your seller do not understand how to do and handle this kind of normal but rare cases then ask your seller that he come here. Then here we can give public teaching what to do and how to do. World is full of stupid sellers who do not care anything. They sell oscilloscopes or other equipments just as beer bottles.

[pofigist]

Muxa52, rf-loop,
Yes, I do not expect this forum to help repair. I myself am 99% sure it was a hardware problem, but after flashing to 100% convinced. I just wrote to the court the result of his actions and correspondence with OWON. And at the moment has finally answered the seller and I will send back an oscilloscope ...
---
Muxa52, rf-loop,
Dya ya i ne jdu ot dannogo foruma pomoschi v remonte. Ya i sam na 99% byl uveren chto eto apparatnaya problema, a posle proshivki ubedilsya na 100%. Ya prosto napisal suda rezul'tat svoih deystviy i perepiski s OWON. A na dannyy moment nakonec-to otvetil mne prodavec i ya otpravlyayu oscillograf obratno...

[rf-loop]

Muxa52, rf-loop,
 And at the moment has finally answered the seller and I will send back an oscilloscope ...

This is good.

And this case it need handle as: "Dead On Arrival" = DOA
(in this case Faulty On Arrival (FOA) is better but this is not in common use )

This was faulty on arrival. Not faulty after period of use. If it fails after some period of use but inside warranty time then it is normal warranty case. Now this is clear DOA case.

If your seller work tightly with Owon he know that Owon have good service for DOA or normal warranty time cases. (they have normal good working RMA procedure)

Owon is not "chinese grey company" who do not care - they care. But naturally becouse they are manufacturer and manufacturer e-mail capacity can not meet well for every single end users. So it is of course better that end users communicate first priority with local sellers as is normal in all where is manufacturer and then lot of local sellers.

Quote from Wiki for this DOA term:

Popular usage

Colloquially, anything which is received in a non-operational (broken) state can be called DOA or dead on arrival (or, alternatively, defective on arrival). If a new product, such as a computer, arrives "DOA" then it is likely that the recipient will call the supplier to get a Return Merchandise Authorization (RMA), a transaction that acknowledges that (apparently defective) goods will be returned to the supplier for refund, replacement or credit. Sometimes it is difficult to actually detect a defective or DOA product. With computers, for instance, it might require a boot image to be installed and run through a test suite to detect any failed parts.

When, as with computers, product complexity is high and diagnostics are involved, the medical metaphor is perhaps appropriate, as complex diagnostics might be required to determine if the product "is really dead".

In another context, "dead on arrival" may be used to describe an idea or product that is fundamentally flawed, and therefore viewed as an utter failure from the start. For instance, if television producers decided that a pro wrestling tournament were to air on a women-oriented network, the concept would be considered "dead on arrival".

Many ebay seller also wrong use this term. (Or eBay DOA is different DOA as buying new things from factory)
They think (sometimes) that if I buy some equipment it can be faulty and it is not DOA becouse power on turns  some light on. (becouse there is some sign of life it is not dead... hehe)

sidenote:
Be careful this DOA term if buy something from eBay and specially from some western countries as example US  becouse every US people know that one light in spectrum analyzer means that it is not dead... so if he promise it not DOA and there is one lamp on after power on, it is just as he have promised. I know this - with experience!!!

[alm]

sidenote:
Be careful this DOA term if buy something from eBay and specially from some western countries as example US  becouse every US people know that one light in spectrum analyzer means that it is not dead... so if he promise it not DOA and there is one lamp on after power on, it is just as he have promised. I know this - with experience!!!

Always assume the worst. If it's guaranteed to be non-DOA, then I expect the power light to light up at least once after power on. It may die at that point, or have major defects. If it were fully working, the description would have been 'guaranteed fully working'. With these assumptions you'll be rarely disappointed, and sometimes pleasantly surprised. Testing means that someone pressed a few buttons and got some sort of response. Calibrated probably means it was hooked up to an out-of-spec voltage source and the numbers looked plausible. Maybe someone adjusted some random trimmers so the 9.9V source read exactly 10.000V. If you expect the seller to do a full performance verification to see if it matches the factory specs, eBay is probably not the best place to look.

This, somewhat tongue-in-the-cheeck, description by HP_Agilent list member Phil Parsons is quite apt in my opinion:

POWERS UP
 Indicator light came on, possibly momentarily. Then switched off before smell of
 burning became too strong.

WORKS
 Switched on without excessive smoke/fume or flames.

TESTED
 AS above but some controls twiddled at random.

FULLY TESTED
 AS above but may show signs of life.......

CALIBRATION STICKERS.
 From when?????????? You have to be kidding. I wasn't born then!

CALIBRATED
 Had a poke around inside -- what are all these little things you can twiddle?
 This is fun -- my 2 year old child had a great time. May never work again.

[somlioy]

So, I got a respond from owon regarding the backlight issue and they sent me a firmware update which surprisingly fixed the problem!!
Something I noticed with this update is that the backlight brightness is stepped 20% a time instead of 10% which it previously did, not an issue for me tho as I don't even use the functionality.

"Utility -> About" says its version 2.4.1, up from 2.3.

[rf-loop]

So, I got a respond from owon regarding the backlight issue and they sent me a firmware update which surprisingly fixed the problem!!
Something I noticed with this update is that the backlight brightness is stepped 20% a time instead of 10% which it previously did, not an issue for me tho as I don't even use the functionality.

"Utility -> About" says its version 2.4.1, up from 2.3.

Utility -> About" says its version 2.4.1, up from 2.3.  <-- oh, now they have worked unexpected fast...maybe coffee is better than green tea... sometimes.

It maybe change this frequency how it swithch "on" "off" this LED driver circuit.
(different FW may have different this "Enable" PWM base frequency... this only suspect)

Sidenote: Innolux specs for LED's voltage is around min 9,3  - max 10,5V  with  nominal current 180mA.
(looks like min is more like typical)

[Sensor Geek]

Somlioy, do you have a contact there at OWON or maybe a link to their download page for firmware updates? I just posted about this on an SDS8202 a little while ago, but have not yet tried to contact them. Thanks for the info regardless, that's encouraging!

https://www.eevblog.com/forum/index.php?topic=5736.0

[rf-loop]

Somlioy, do you have a contact there at OWON or maybe a link to their download page for firmware updates? I just posted about this on an SDS8202 a little while ago, but have not yet tried to contact them. Thanks for the info regardless, that's encouraging!

https://www.eevblog.com/forum/index.php?topic=5736.0

Owon have not public download center.
You  can send email to Owon and tell problem and ask if FW update maybe solve it. They ask your full serial number and some day they may send  to you FW (normally serial number locked)
(with serial number database they know what is ok for your HW)

After Sales Service:  service   at   owon  dot  com  dot  cn

But if you have buy it from local distributor "please first contact local distributor".

[somlioy]

Yeah, I got the firmware directly from owon.

[tinhead]

Yeah, I got the firmware directly from owon.

if you don't mind uplad the firmware somewhere and send me a link (PM).
I might need it to continue the hack.

[blueflash]

Hi Folks,

got a new info from my dealer. OWON will make the firmwareupdates available on the official website for all SDS models.
Planned start of the download site is mid of december.

This would be nice and quite more comfortable.

[kaz911]

Hi Folks,

got a new info from my dealer. OWON will make the firmwareupdates available on the official website for all SDS models.
Planned start of the download site is mid of december.

This would be nice and quite more comfortable.

I was told the same by one of the Owon seniors a week ago - but was not given permission to publish it :-) But I got same message - so that is good getting confirmation from someone else :-)

I think Owon has started to listen - and does follow the discussion both here and Mikrocontroller.net

:-)

[0xdeadbeef]

It's cool to hear that it's actually true, but there were hints more than one month ago that this could happen. Earlier in this thread I posted a quote from a mail I got in late October which commented on one of the bugs I reported with "... can be solved by upgrade that we'll have a new software for this on our website."

[rf-loop]

Owon have also developed SDS.
They have changed whole front end construction. (and also some other construction things what have been not so good). Whole adapter board is designed agen and also mainboard have lot of changes. So, all pictures and opinion about some construction details what you have here seen. Most of these are now obsolete!

Of course some part of development is for manufacturing process so that assembling is more ergonomic and some work phases need less work and also mistake posibility is reduced.... etc. (normal production development) But most of these also give better reliability and better functioning.



Also they have changed some relays to better quality.

Old talking about dim display. Forget also, now they drive baclight with full Innolux specified current. (this really do not matter in battery use. And if really critical time user can adjust it but maximum is not now limited too low)

and so on...

later, after I can do more labs, then more real data, not opinions.

But this I can tell as preliminary for frequency response and risetime etc... Owon have done very good work.

[tinhead]

rf-loop ... pictures please

(editing my comments right now ...)

[rf-loop]

rf-loop ... pictures please

(editing my comments right now ...)

I have not any public pictures.

[rf-loop]

I have tested one new individual SDS7102V 

Using 1MHz as reference level.
V/div 50mV~
Signal exactly 6div p-p

Single and double channel in use.
Flatness is extremely good. Just flat up to around 85MHz
Before there was small high between 40 - 60MHz. (nearly +1dB, some variations between single units)
Now response is just flat.
100MHz -0.6dB   This is good.

Single channel in use:
-3dB >200MHz  (result was around 240MHz but this test need repeat and cross test with other equipmen for avoid error)
-6dB >300MHz  (result was around 350MHz but this test need repeat and cross test with other equipmen for avoid error
Measured with good coaxial cable and Tektronix 50ohm feed thru terminator  on scope input.
Generator is HP8644B and checked its flatness is perfect and inside specs.

Also I noticed that 250MHz noise is around 6dB more low than before. (but also before, individual units have differencies... I have find around +-5dBvariations between single units so this finding is not meaninful before test more units and can see if average is really better now.

This freq response finding was real surprice.
 
But also we know that if scope is named as 100MHz scope it is nice if flatness is very good up to this frequency, and now this is.  If take some 200MHz (1GS/s)  ready made oscilloscopes this 100MHz Owon is good competitor and it may even win.
 
Becouse this scope have also lot of capture memory with full speed up to 10M  it keeps 1GS/s or 500GS/s up to 500us/div or up to so aliasing problem is not very high becouse Nyquist is 500 or 250MHz  up to 500us/div if single channel use or with 2 channel use up to 1ms/div.

So, this scope do not need any posibility to hack BW. This is working tool, not hacking hobby object.
Good 100MHz oscilloscope and 200MHz oscilloscope if look many competitors ready made 200MHz scopes.

[alm]

>200 MHz -3 dB point is awfully close to the 250 MHz Nyquist frequency for a 500 MS/s sample rate. I'd expect aliasing to be an issue.

[rf-loop]

>200 MHz -3 dB point is awfully close to the 250 MHz Nyquist frequency for a 500 MS/s sample rate. I'd expect aliasing to be an issue.

In single channel use as there read. (but analog BW is also of course with 2 channel.)

Yes aliasing is always problem with all low price digital scopes and also with expensive scopes.
If need really scope what never have aliasing problem it can buy analog oscilloscope. I want some day find littlebit better analog (today my analog limit is around 500MHz... but if find 1GHz analog (Tek 7000 series) maybe it is solution..

More aliasing with models what have not deep full speed memory and becouse this they, with lower horizontal speed, drop samplerate to very low.

Now this measurement was also done without probes. Probe is good filter.

Single channel it use 1GS/s down to 500us/div. (With 2 channel it use 500MS/s down to 1ms/div)
1ms/div. Nice for looking 1kHz. I can not imagine how much 250MHz signal is together with typical case when looking 1kHz.
If looking fast rising pulse edge. Well yes it includes high frequencies. 1ns risetime and there it go.

In what kind of situation you mainly mean this aliasing problem (if keep mind where we are in price class and competitors)

Two channel use and signal have markable amount >250MHz frequencies if use 2ns/div - 1ms/div speed per div. If look audio signals and afraid high frequencies aliasing... well. There is 20MHz BW and around 5MHz if switch probe to 1:1. And it is good to note, 1ms/div and looking example 1kHz or 500Hz signal... and yes... if there is >250MHz doughter signals with this low freq signal they do aliases. 

Where is other cheap oscilloscope what sample 500MS/s for both channels if using 1ms/div speed.
If there is other 100MHz scope what have corner freq around 100-130Mhz and samplerate is example 50MS/s in same 1ms/div situation.. well... nyquist is 25.. and analog channel is widely open up to >100MHz but becouse it is not Owon.. it is not problem even if it is famously hacked to 100 - 200MHz... now it hack is welcome... so where is real problem.

Just with these aliasing problems it is easy understand whu full speed deep capture memory is extremely good. Some peoples have tell me that they do not need so much memory. Only normal oscilloscope screen is enough. hehe... after I show what this deep and fast memory really means they are surprised. But still, it helps only some. So do not insert >250MHz with 2 channe use and not >500MHz if one channel in use, then you have high aliasing problem.

But I understand well that name Owon make some interference and it may also make aliasing problem more bad becouse this is Owon.. we can take one 100k memory Agilent and compare aliasing....   my 1980's HP digital scope is clever. It give text warning on the screen about possible aliasing situation.


Here some pictures.
(do not care memory depth becouse with 2ns/div it use ofcourse highest samplerate also with 1k just as with 10M)

1. single channel, fast risetime pulse and 1GS/s   (pulse itself risetime is 1,3ns)
2. double channel, fast risetime pulse and 500MS/s    (pulse itself risetime is 1,3ns (generator minimum and it is ok))
1 and 2 signal exactly same.

3. double channel, "slow" risetime pulse and 500MS/s (pulse risetime adjusted littlebit  slower than
1 and 2 pic.  Not know exactly but something like 2-3ns (in this generator this adjusted risetime do not work perfect - need cal or new better generator (this is HP 8161A 100MHz programmable pulse generator with options.))

Here can see that this fast risetime is too fast for 500MS/s  (it includes markable amount frequencies over Nyquist and so corners "wobble")

All pictures have same persistence for looking variations enough long time.

Also signal matching to scope is not perfect. (it can not be becouse feed trough 50ohm is connected to reactive input. )

So also signal risetime (nominal 1,3ns) is only in generator output connector if it is matched perfect.

Later I try find scope risetime better with Tektronix fast risetime gen. (around 70ps)
Now I do not find this output adapter connector..

[rf-loop]

Here some leak about details  - some improvements.

There is more but here only some. Also these may later come obsolete becouse Owon look carefully product and they want do improvements as need for quality, reliability and functionality.

First, all what you have before know about Owon inputs and also some other things construction (early versions) you can forget.

All this  https://www.eevblog.com/forum/index.php?topic=4412.msg65047#msg65047  is history.

Front end construction have totally changed (circuit not so much) and what I can see with tests, this change is really big improvement also in signal. Also inside RF shield there are full area  wall between channels.
Components costs is maybe more high but final is lot of better reliability and better economy in production work. Also it rise reliability. Also now possible service is lot of more easy.

Someone before did not like battery compartment / adapter board mechanical situation (it did not normally touch to this inductor, but now adapter board is lot of better.) . Whole adapter board is totally designed agen.
Also there is not anymore any VGA cable crossing over adapterboard and mainboard. (becouse main board is also partially designed agen and now VGA is also there near Samsung processor and memories  and signal go directly on the board layers.)  Adapter board have one "smile" mistake. This one capacitor have lot of free room and it can install also now normally but accidentally in production it have still assembled as before.. (on this individual board)

Then encoders. (also there can see one button golden contact area)
Encoders are not best but not at all poorest. They are (in this unit) made by: Ningbo Everbest Electronics & Technology Co., Ltd. 

Outside from pictures: They have changed relays. They are now Fujitsu  Golden  contact relays designed also for RF use.
My opinion without enough knowledge is now that they are better than these older NEC's.(?)

And if someone look some old pictures about Power Unit. As informed before its mechanical construction have changed better.

Also bottom under display and right side of dislpay push buttons circuit board is totally new, now it do not look like prototype.

Absolutely best improvement is this front end. Please Owon, do not give any your designer  touch it now without really heavy well argumented reasons.

What they can do is design agen ADC area of PCB so that it follows tightly National ADC08D1000 and ADC08D500 application notes and good other design rules and principles.
(this not bad now - but, good can still be better without growing costs and then it can also competite with higher level scopes in some features (yes it can also today shoot down some old good names (low end models) but if someone do it... after this he break consensus "gravitation" and he fly alone... there are rules that it need tell how good is tektronix or agilent or lecroy - if you do this then you are "good" people.. and all give applause. )