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

[AndrejaKo]

It looks pretty much like my adapter board.

The safest and perhaps most obvious solution would be to ask Owon and let us know what they answer. This board does not have the affected capacitor as a through-hole component (or at all, I'm not 100% sure at the moment), as far as I can see.  On the other hand, maybe there are some other "easy" modifications that can be done on it to improve performance.

If I remember correctly, that Russian guy (whose username I can't remember) had similar board and made some modifications to it. That was maybe 6-8 months ago and was a bit more complex than adding a single ceramic capacitor.

[TomC]

I received the new PSU board. After I opened the case, I noticed my adapter board is different (see the picture below). What should I do?

mlhstock,
I looked at one of your previous posts and it states that your scope's serial number is 1303xxx. This means that your scope was built on the 3rd week of 2013. Now here is the puzzling thing, my scope's serial number is 1246xxx, meaning that it was built on the 46th week of 2012, yet, my adapter board is version 3.2. Now, how is it possible that your scope, which was built around 2 months later, has a version 3.0 adapter board. I don't want to speculate, but it gives me an uneasy feeling that there is a possibility that the adapter board in your scope is not the original one. I would very carefully check the scope for any additional telltale signs that may lead you to believe that it may have been altered or refurbished by the dealer before it was shipped to you.

[rf-loop]

In some cases some older version may be better than some  later version.

[Carrington]

I received the new PSU board. After I opened the case, I noticed my adapter board is different (see the picture below). What should I do?

You're not alone. The design of version 3.0 is crap, continuous gnd plane cuts, parallel capacitors that resonate at frequencies where noise is generated, DC / DC Boost with input connected to critical places (everyone should know that at the input is where more noise is generating by a boost), etc.

I tried to explain to OWON that for those who have the 3.0 version a 1n capacitor is not enough, but there is no way. 

[lemon]

It looks pretty much like my adapter board.

The safest and perhaps most obvious solution would be to ask Owon and let us know what they answer. This board does not have the affected capacitor as a through-hole component (or at all, I'm not 100% sure at the moment), as far as I can see.  On the other hand, maybe there are some other "easy" modifications that can be done on it to improve performance.

If I remember correctly, that Russian guy (whose username I can't remember) had similar board and made some modifications to it. That was maybe 6-8 months ago and was a bit more complex than adding a single ceramic capacitor.

Siri was.
Page 62.
It is better to see the rf-loop's mod (version 2b) from Electronics and Owon SmartDS oscilloscopes Forum (http://owon.forumup.com/) but all these mods demands tools and very well smd soldering knowledge.

[Carrington]

It is better to see the rf-loop's mod (version 2b) from Electronics and Owon SmartDS oscilloscopes Forum (http://owon.forumup.com/) but all these mods demands tools and very well smd soldering knowledge.

Sure?

This modification version 2b, for all I know can use directly for 3.2 adapter board and directly or nearly directly for 3.1 adapter board, only.
Cheers!

[kptn]

Thank you all the guys for starting and keeping this thread!

Below is my experience with "GND noise" mods for V3.0 adapter.

I am also owner of SDS7102. My SDS has OWON's manufacturing date code: 1223.
PSU is PCB-T115-J Rev6. Adapter is CONNECT_V3.0
My original Vp was aprox. 180-210mv.

I've applied DIY mod 2b designed by honoured rf-loop
with necessary alterations for T115-J Rev.6 PSU's  and V3.0 adapter's PCB layout.

Upon application of mod 2b for PSU I've got positive effect.
Application of mod 2b for V3.0 adapter probably also had lowered the noise a little bit but not sufficient enough.
At this moment the Vp that I have is 80-90mV, so it still needs improvement.

V3.0 produces TFT LED back light voltage using 5.5V as a source.
V3.2 takes +8.4V from PSU as a source.
This difference affects schematics and PCB routing as well.

I've reviewed this thread and found out two cases of "GND noise" work over V3.0:

• first one was made by the forum member with logname EU1 started at page 45 message Id #664
   and finished at page 47 #701 with resolution:
   

  Resolved by adding an inductor on 5.4V rail as it was proposed by OWON.
• second one was made by the forum member with logname Siri (he had V3.0) aprox. at page 62
   with resolution at page 65 #971
   

  I wonder how you managed so well to reduce noise backlight?

    Next was the question from the forum member alexuresp (#972):
  

  Now the main noise from LCD. rf-loop how you fight with this ?

    I found no answer on this question.
  

So it looks like that DIY solution on how to reduce noise on V3.0 adapter is yet not fully disclosed at this time.

[mlhstock]

mlhstock,
I looked at one of your previous posts and it states that your scope's serial number is 1303xxx. This means that your scope was built on the 3rd week of 2013. Now here is the puzzling thing, my scope's serial number is 1246xxx, meaning that it was built on the 46th week of 2012, yet, my adapter board is version 3.2. Now, how is it possible that your scope, which was built around 2 months later, has a version 3.0 adapter board. I don't want to speculate, but it gives me an uneasy feeling that there is a possibility that the adapter board in your scope is not the original one. I would very carefully check the scope for any additional telltale signs that may lead you to believe that it may have been altered or refurbished by the dealer before it was shipped to you.

TomC,

I have the same doubt, but I couldn't find any trace of repairing. The dealer told me the scope was shipped directly from the warehouse. Anyway, I asked for a refund or exchange and the dealer is waiting for the response from Owon before he sends me a new version scope. The non-sense adapter card version is one of reasons why I ask for exchange. Another reason is because I noticed the fan is quite noisy. I think people commented that the fan noise should be hardly inaudible, but mine is as loud as my very old Tektronix analog oscilloscope.

[TomC]

TomC,

I have the same doubt, but I couldn't find any trace of repairing. The dealer told me the scope was shipped directly from the warehouse. Anyway, I asked for a refund or exchange and the dealer is waiting for the response from Owon before he sends me a new version scope. The non-sense adapter card version is one of reasons why I ask for exchange. Another reason is because I noticed the fan is quite noisy. I think people commented that the fan noise should be hardly inaudible, but mine is as loud as my very old Tektronix analog oscilloscope.

Good for you! Hope they do the right thing and agree to give you the latest version scope they promised you in the first place. As for the fan, I have several older Tektronix scopes and the fan on my SDS7102 is quieter than everyone of them.

[mlhstock]

I got reply from my dealer and Owon denies there're multiple versions of adapter boards, here's the quote from dealer's email

we got reply from manufacturer, they said there is no old generation for adapter board, they only have one version

I am really pissed off by Owon's response and ask my dealer give me the full refund, no more exchange. If Owon lied about the adapter board, how can I trust them that they will keep 3-year warranty promise? I don't want to have business with a liar even the oscilloscope has a good price/performance ratio.

[Carrington]

I am really pissed off by Owon's response and ask my dealer give me the full refund, no more exchange. If Owon lied about the adapter board, how can I trust them that they will keep 3-year warranty promise? I don't want to have business with a liar even the oscilloscope has a good price/performance ratio.

Honestly, I think it's laughing at us, Owon given me a different answer every time.

"I don't want to have business with a liar."  Neither I.

[TomC]

I got reply from my dealer and Owon denies there're multiple versions of adapter boards, here's the quote from dealer's email

we got reply from manufacturer, they said there is no old generation for adapter board, they only have one version

I am really pissed off by Owon's response and ask my dealer give me the full refund, no more exchange. If Owon lied about the adapter board, how can I trust them that they will keep 3-year warranty promise? I don't want to have business with a liar even the oscilloscope has a good price/performance ratio.

It's a shame that they are pointing fingers at each other, can't get much resolved in that state of mind. The dealer says the scope came directly from the warehouse, Owon says there is only one version of adapter boards. Perhaps they are both telling the truth but overlooking the obvious. Owon can't possibly mean that the same adapter board version has been used ever since the SDS series was released, it's too much of a fib even for the best poker faced liar, tons of evidence on the internet to debunk that in two seconds. But if what they mean is that only one version was used on scopes built during 2013, that would be much more credible. The dealer may not have changed the board, after all, he just had the scope drop shipped from a warehouse somewhere. What is not known, is what happened at the warehouse. For example, stocking returns as brand new products is not an unheard of sleazy practice.

In any case, you are probably better of getting your money back. It seems that your dealer is not willing to take some responsibility for what happened and is pulling every trick in the book to keep his profit intact. If you decide to try again for an SDS scope I would definitely use a different dealer. Good Luck!

[mlhstock]

But if what they mean is that only one version was used on scopes built during 2013, that would be much more credible.

It seems still have problem to explain the strange combination: S/N 1303xxx, Ver3.0 adapter board inside and an instruction of adding 1000pF capacitor for Version 3.2 adapter board. Whatever. I will fight for my money back.

[rf-loop]

It seems still have problem to explain the strange combination: S/N 1303xxx, Ver3.0 adapter board inside .......

Is it SDS7102V ?

This is really strange. I have lot of documents about S/N 71021303xxx
(SDS7102V)

Something is very strange if there is V3.0 adapter board inside and it is S/N71021303xxx serial.
Is this unit really left from original Owon factory as it is now.
I can not proof it of course - all is possible.
But in this point now, without more data it feels like someone lie.
Btw, is there scope back, scope carton AND scope also display exactly same serial number?


---------------------
It need also note that I have personally seen also that inside same version adapter board (example SDS7102_CON_3.2) there may be small differencies. Perhaps some times after changes someone have forget update also print mask.)
---------------------

Btw, about communication with chinese.
Try small example.

Write your letter as you do it but just before send, copy paste it to example google translator  and translate it to chinese. After then, copy paste this translation agen to google translator and translate this chinese letter to english.  Now, how you answer this letter?
------------------------------------


Bit modified/simplified/imagined old case with Owon:
I:  I need spare part.  I need adapter board version 3.2 for SDS7102V....
O:  What is adapter board?
I:  it is board between PSU and main board...
O: What you mean about adapter board, no need adapter board, please send picture what you want...
I: here is picture (picture including board version)
O: Ok, we can send it to you.

later...
I get exactly this board what was in my picture. I think if they copy my picture and made it....hahah)

[rf-loop]

..... and an instruction of adding 1000pF capacitor for Version 3.2 adapter board.

Who and where have give this instruction: Owon?

[lemon]

..... and an instruction of adding 1000pF capacitor for Version 3.2 adapter board.

Who and where have give this instruction: Owon?

Yes, this instruction is from Owon.
TomC, had this instruction from Owon, when he received the new psu board. There was a video how to change the new psu and some instruction how to add this smd capacitor to the 3.2 adapter board between the legs of electrolytic capacitor.
Probably, they believes that the combination of new psu and smd capacitor adding is decreasing the noise at the well level for 2013 versions.
TomC asked them if they are going to produce new adapter version. Their answer was no for this time.

For the mlhstock's situation, I believe that there was a third person between Owon factory and dealer. Probably the dealer bought the scope not directly from Owon factory but from someone Chinesse person.

[lemon]

Thank you all the guys for starting and keeping this thread!

Below is my experience with "GND noise" mods for V3.0 adapter.

I am also owner of SDS7102. My SDS has OWON's manufacturing date code: 1223.
PSU is PCB-T115-J Rev6. Adapter is CONNECT_V3.0
My original Vp was aprox. 180-210mv.

I've applied DIY mod 2b designed by honoured rf-loop
with necessary alterations for T115-J Rev.6 PSU's  and V3.0 adapter's PCB layout.

Upon application of mod 2b for PSU I've got positive effect.
Application of mod 2b for V3.0 adapter probably also had lowered the noise a little bit but not sufficient enough.
At this moment the Vp that I have is 80-90mV, so it still needs improvement.

V3.0 produces TFT LED back light voltage using 5.5V as a source.
V3.2 takes +8.4V from PSU as a source.
This difference affects schematics and PCB routing as well.

I've reviewed this thread and found out two cases of "GND noise" work over V3.0:

• first one was made by the forum member with logname EU1 started at page 45 message Id #664
   and finished at page 47 #701 with resolution:
   

  Resolved by adding an inductor on 5.4V rail as it was proposed by OWON.
• second one was made by the forum member with logname Siri (he had V3.0) aprox. at page 62
   with resolution at page 65 #971
   

  I wonder how you managed so well to reduce noise backlight?

    Next was the question from the forum member alexuresp (#972):
  

  Now the main noise from LCD. rf-loop how you fight with this ?

    I found no answer on this question.
  

So it looks like that DIY solution on how to reduce noise on V3.0 adapter is yet not fully disclosed at this time.

Very usefull summarise, I supposed.
kptn we have the same adapter version.
As you can see at my previous messages, I have make same mods like you to my psu and adapter board.
I would like to ask you some things.

What value of inductor you add to 5.4 rail? My scope has this adding from factory but this adding was by hand. It is an after production adding with few words. My this inductor value is 10mH but I have measured this only 3.2mH. I am thinking to change this with an other with 10mH value. It is at the same position as Siri's photo present (the inductor under the ribbon cable)

.

At the last I would ask you if you can upload a photo from the upper of your adapter board.

[rf-loop]

..... and an instruction of adding 1000pF capacitor for Version 3.2 adapter board.

Who and where have give this instruction: Owon?

Yes, this instruction is from Owon.
TomC, had this instruction from Owon, when he received the new psu board. There was a video how to change the new psu and some instruction how to add this smd capacitor to the 3.2 adapter board between the legs of electrolytic capacitor.
Probably, they believes that the combination of new psu and smd capacitor adding is decreasing the noise at the well level for 2013 versions.

This one capacitor do not reduce common mode noise what is produced by TFT LED SMPS.  And there is also 5.5V SMPS circuit (this have high noise)  and 3.3V SMPS (this is not so noisy). This capacitor only filter small amount of output RF noise to LED's from backlight SMPS circuit.
It is very pity they do not want understand this whole case.
I have told that filtering some bad SMPS circuit output do not solve this issue. They do not understand how this GND "pollution" works.
 
Only solution for good result is design (I mean real design including test redesign iterations) totally new low EMI  PSU and totally new low EMI Adapter board. Including also redesign for TFT databus.  These need redesign just from scratch. First delete everything from old boards.
It need do only once. It need only one good design, no need then make frequently small changes after changes.

If they continue this road what they now use... they destroy themselves.
But this "captain of Titanic" do not listen anybody.
No one can not force them to do right things.

Money can perhaps teach, but this lesson is perhaps coming too late if they want rescue themselves.  They should be wise in advance.
They have now loosed nearly half year and lot of customers. And still this stupidity continue.
If they do not now, just least immediately now, turn they course it may lead to crash and there is no road to back.

Still I wonder why we have Owon scopes in stock, and I'm personally absolutely sure they are directly from original Owon factory product line and they do not have this level of this issue.

[rf-loop]

.

[/quote]

What version read exactly on this adater board. (this board is (Owon) modified board from some version)

Only case I have seen this board is in one "siri" picture. Never seen this version live in my hand. (also this board may have totally different backlight SMPS circuit than V3.2)
(I wonder how many versions and modified sub versions they have without change in version number)

[Carrington]

V3.0 is the same as mine. It came with a motherboard of mid-2012.

Obviously, this is modified for me. That cut in the ground plane (RED) is critical. And C44, 45 and 36 resonate at noise frequencies, better remove C36.

[lemon]

Exactly, version 3.0
An other photo from version 3.0 (from post #928, page 62, Siri's adapter photo), Adapter board: SDS7102_CON_V3.0 (2011.11.14)

It appears the adding inductor at the rail of 5.4V.

[Carrington]

Yes,  that shows that they knew the noise problem, and tried to correct it with that inductor, as a filter.

[Carrington]

Exactly, version 3.0
An other photo from version 3.0 (from post #928, page 62, Siri's adapter photo), Adapter board: SDS7102_CON_V3.0 (2011.11.14)

It appears the adding inductor at the rail of 5.4V.

Who designed this? He was drunk? I'll post more pictures from other tinkering that I have found. Sorry wanted to say botched (made by OWON), not tinkering.

[lemon]

Of course they knew about ground issue but if I remember right this inductor adding wasn't for decrease the ground noise but for lcd noise about.

Carrington I see some modification at your board. I have adding some arrows at various areas. Can you give us the information what you have done?

1) you have removed the factory inductor and you put two other smd inductors (what value) and one smd decoupling capacitor...
2) you removed the electrolytic and a smd ceramic capacitor and....
3) probably you have add a decoupling capacitor...
4) you have removed the U13 chip...
5) ??

[Carrington]

Of course the knew about ground issue but if I remember right this inductor adding wasn't for decrease the ground noise but for lcd noise about.

Carrington I see some modification at your board. I have adding some arrows at various areas. Can you give us the information what you have done?

1) you have removed the factory inductor and you put two other smd inductors (what value) and one smd decoupling capacitor...
2) you removed the electrolytic and a smd ceramic capacitor and....
3) probably you have add a decoupling capacitor...
4) you have removed the U13 chip...
5) ??

1) you have removed the factory inductor and you put two other smd inductors (what value) and one smd decoupling capacitor...
 
  Several testing to determine the source of the noise.
  Yes, by a ferritebead and a 10uF ceramic capacitor. Sorry, I do not know what kind of ferritebead is, but very low DC R.

2) you removed the electrolytic and a smd ceramic capacitor and....

  I get a attenuation of the HF noise.

3) probably you have add a decoupling capacitor...

  Yes 10uF, and another ferrritebead. (-7V)

4) you have removed the U13 chip...
 
  Several testing to determine the source of the noise. I used another 5V source. Really was ~5V6 of a DC Battery.

5) ??

  I check the variations of the noise, changing the ground plane cuts.

This modifications are only a test.


It's a shame, but due to the indifference of the manufacturer for months, many of us have had to modify it by necessity. Now OWON modifies the PSU, but not the adapter, which is another source of noise, rfloop indicated the need to modify this too, I think.

Another test on the PSU, see the picture. The effect is similar to put a ferrite in the cable of the PSU.