believe it! - Page 1
Forum section: electronics / testgear

author: GEuser
author_rank: Frequent Contributor
timestamp: August 06, 2012, 04:34:11 am
content: Q

author: aghp
author_rank: Regular Contributor
timestamp: August 06, 2012, 08:26:52 am
content: HiJune 22, 2012, 03:24:34 AM I did try help you.I give to you list of instructions and ask you answer after you have made these tests exactly.Never get any answer from you for diagnosing this problem and then possible give more advice for continue.But of course all can do also with diy "try-mistake-try" method. Sometimes is good luck and then ask "oh what happend"...Also there is available illustrated instructions for disassemble and assemble this scope. (it is littlebit obsolete for newest HW but for its purpose it give enough information - also after some changes in construction. For more deep works it is obsolete and there is not public material for this.Btw. yellow-green protective ground lead is normally so short that if you do not pull it out from mains plug or take out other end (pow supply PCB) screw you can not well separate bacside of oscillosccope. (if pull out from mains connector end, then check connector tightness). It do not need high force (sometimes it is not very tight) so I'm "nearly sure" (and becouse in disassembly phase you did not know it), you propably have used some (small) force and it have pulled out from connector so that you did not notice it. (of course there is 1:10000 posibility that factory have left it out but it is extremely rare and nearly impossible becouse every scope go to QC and safety check. If mains protective ground is open it fails in test. But humans work all is possible.)Example Owon oscilloscopes what I have serviced and/or sold I have never find open safety ground connector (and I do this "safety" test for every oscilloscope). Also after service this wire need always check carefully and tighten connectors if need. This is normal primary fundamental in every professional electric and electronic service workshop. Also it is good practice for test this kind of things if sell any equipment what is made in developing or underdeveloped or declining countries without tight quality control and standards.Edit/Addendum:As normal in serious workshops also I have HP + 2 trimble GPS (tribled for control = If one is different from the other two, it can be voted out) reference and well adjusted Rb's (tripled) as "house standard" (GPS I use for control that my freq references are ok, this is becouse GPS short time accuracy is not good as all know)I have not find yet any Owon SDS what is out of specifications reference oscillator. But no one know how these go after long time ageing. Some units are nearly specifications borderline error. (I have not followed long time so I do not know what is typical ageing direction and what amount)Also I have not find any Owon what is out of specifications if look voltage levels accuracy (after self calibration).I have checked sold (and stock) equipments with Tektronix CG5011 and or CG5010. (my cal generators do not have certified calibration valid today but all my indirect tests show also that they both are in ok accuracy (without official ISO certificate))

author: aghp
author_rank: Regular Contributor
timestamp: August 06, 2012, 08:55:14 am
content: Quote from: GEuser on August 06, 2012, 08:51:19 amNow I understand also why your communication with Owon fails.

author: digsys
author_rank: Unknown
timestamp: August 06, 2012, 12:31:45 pm
content: Quote from: GEuser on August 06, 2012, 09:04:48 amGive the guy a break mate. I bought the same DSO a few weeks ago AFTER carefully reading through ALL the threads.The aghp user has been VERY helpful to MANY people, without ANY expectations !! Don't go mouthing off without doingresearch or you'll quickly find yourself on the "idiot" list, We have a few here already. It's not a nice way to start.Just about everything you buy now days will have some kind of "bug". Either fix it or put up with it, If you're lucky,someone (possibly even the manufacturer will solve it). For the price we paid for the SDS7102, it's a bargain !!

author: SeanB
author_rank: Super Contributor
timestamp: September 02, 2012, 01:31:24 pm
content: If it is alcohol and you use a little elbow grease it will work. If you have some really potent homebrew ( double distilled or better, and it burns with a blue or colourless flame) it will work as well.

author: aghp
author_rank: Regular Contributor
timestamp: September 02, 2012, 03:49:43 pm
content: I have seen many Owon SDS series oscilloscopes (made for European markets) inside and never seen like this.Sometimes I have seen some residues and fingerprints but anything like this total waste station garbage.Also I see some other signs what let me think this unit is some kind of junk. But why this unit is packaged and sent to some seller and finally to end user. This unit belongs to factory inside material recycle garbage.Did you find any signs that this unit have been opened before you did it?( before there was also some suspect that protective ground wire was perhaps not ok)Also these front end RF shields soldering are strange. What I have seen before it do not match.Then I can see (perhaps) there is some marking pen traces on the board. Never seen these in new factory fresh unit.Strange is also in one picture, there can see RF shield can is bent in a lot of.Are there different standards product lines in Owon for example domestic markets?If I'm you I send these pictures and explanation to Owon (and not to some basic level "email answering workers") and tell that you do not accept this junk and also ask Owon also inspect in factory how it is possible this unit have passed QC and sent out from factory.Ask Owon give free DHL to return this unit and send unit what meets normal factory quality standards.This information need reach factory higher level peoples who are responsible about quality and who have real power for solve your case.-aghp

author: marmad
author_rank: Super Contributor
timestamp: September 02, 2012, 08:31:52 pm
content: Quote from: aghp on September 02, 2012, 03:49:43 pmRf-loop - I think maybe you haven't been looking that closely. Here is a close-up pic from the inside of one of the very first SDS7102s ever manufactured; I have quite a few photos with fingerprints. I have to assume that it's a common occurance in Owon's manufacturing. Even so, I'm not necessarily worried about fingerprints in the solder mask - but it is rather troubling to see the fingerprints overlapping the BGA devices.

author: marmad
author_rank: Super Contributor
timestamp: September 03, 2012, 09:44:16 am
content: Quote from: GEuser on September 03, 2012, 01:10:52 amThat's just the pin 1 marker for the IC - nothing to worry about with that.

author: T4P
author_rank: Super Contributor
timestamp: September 26, 2012, 05:36:05 pm
content: It costs about 80 bucks direct from china, seems like it isn't a cheap arse one.

author: saturation
author_rank: Super Contributor
timestamp: October 04, 2012, 01:30:41 pm
content: Thats a lot of work, but great recovery effort! Thanks for documenting.

author: tlu
author_rank: Regular Contributor
timestamp: October 05, 2012, 03:32:01 am
content: Hi GEuser,Nice tear down, even the battery....wow! I only wish it had better UI and firmware. Features are limited as well. Hopefully this can be hacked. Does anyone know the underlying OS? Is it linux-based or windows-based or neither? I'm in between picking up this scope or the Hantek as budget is the gating factor for me. GEuser, what is your impression of the scope in terms of functionality and signal fidelity?I saw the video by marmad and the over all scope is physically beautiful and nice big display. However, the firmware seems lacking in features such as dual window is not even implemented and no fine adjustments pointed out by marmad. Well, since you have the scope on hand I would also like your opinion.Thanks,Tim

author: Dread
author_rank: Regular Contributor
timestamp: October 05, 2012, 03:44:50 am
content: I love my 8202VWorks very well and I have had no issues with it. The Battery pack is a fantastic option, I have already used the scope on a remote location and it really was nice not having to look for a spare power plug when I was working in the field also during battery mode the scope is not grounded so that could come in handy. (Assuming you of course plugged it out)

author: muvideo
author_rank: Frequent Contributor
timestamp: October 05, 2012, 10:31:53 am
content: Hello, thank you for the info, so the battery is simply two cells in series and twowires to connectors? No other electronics inside, balancing the cells andchecking the temperature and voltages? If so it's not good.Quote from: GEuser on October 05, 2012, 10:07:42 amAfaik eclipse is only a general purpose ide, and java enviroment needs a "normal" OS.I remember somewhere that tinhead mentioned that owon doesnt use any OS, oruses some proprietary/non standard one, is it also possible that they programmedthe thing "bare metal" ?Fabio.

author: Bored@Work
author_rank: Super Contributor
timestamp: October 05, 2012, 02:43:45 pm
content: Quote from: GEuser on October 05, 2012, 12:03:53 pmEquinox would mean they use the Eclipse rich client platform. Equinox provides an OSGi framework - a thingy to plumb together components. You hack and slash your application into so many small components and libraries you no longer understand what all this is about. Then you use a component framework to glue it all together again, full with enterprisy stuff and management and whatnot, and hope it all starts up, and all the components are finding together.Now, I have seen OSGi used on an embedded system once. But it was running on top of an operating system, and was a prototype ported from a desktop system. Could it be that the Java stuff was for the PC part of the software, i.e. the firmware updater, not the firmware itself?

author: PA0PBZ
author_rank: Super Contributor
timestamp: October 05, 2012, 07:08:30 pm
content: It certainly looks like OSGi:Code:#Product Runtime Configuration Fileosgi.splashPath=platform:/base/plugins/com.owon.uppersoft.patcheclipse.product=com.owon.uppersoft.patch.productosgi.bundles=org.eclipse.equinox.common@2:start,org.eclipse.core.runtime@start,RXTXcomm,ch.ntb.usb,com.owon.uppersoft.common,com.owon.uppersoft.patch,javax.servlet,org.eclipse.core.commands,org.eclipse.core.contenttype,org.eclipse.core.jobs,org.eclipse.core.runtime.compatibility.auth,org.eclipse.core.runtime.compatibility.registry,org.eclipse.equinox.app,org.eclipse.equinox.preferences,org.eclipse.equinox.registry,org.eclipse.jface,org.eclipse.osgi.services,org.eclipse.swt,org.eclipse.swt.win32.win32.x86,org.eclipse.equinox.launcher,org.eclipse.equinox.launcher.win32.win32.x86osgi.bundles.defaultStartLevel=4

author: tlu
author_rank: Regular Contributor
timestamp: October 05, 2012, 08:50:25 pm
content: If the firmware is implemented with Java, does this mean we can write custom firmware for this device?Thanks,Tim

author: 0xdeadbeef
author_rank: Super Contributor
timestamp: October 06, 2012, 11:08:54 am
content: The firmware updater is a poor Eclipse rich client implementation, the scope's firmware isn't of course.

author: tlu
author_rank: Regular Contributor
timestamp: October 06, 2012, 12:52:20 pm
content: Help me understand where in the schematic did you applied your modification for the switch? Why did Owon design to have small current drain when battery not in use? Poor design or intentional?Tim

author: digsys
author_rank: Unknown
timestamp: October 06, 2012, 01:35:04 pm
content: Quote from: GEuserVery handy, I was about to pull mine apart to do similar. Do you have a slightly better res of the P/Supply? Did you get ALL the schematics?Quote from: tluLooking at the schematic, if SOCBAT is connected directly to the battery, then the leakage is due to the battery powering the feedback circuitlocated next to it. In which case, the charge circuit is a basic trickle charger ONLY. Not a "nice" method, but unless the current is set too high, reasonableenough. Definitely something that could be "fixed".EDIT: Posted this 2 secs after your post GEuser

author: digsys
author_rank: Unknown
timestamp: October 06, 2012, 01:46:29 pm
content: Quote from: GEuserIt is QUITE a common "problem" with switch-modes ONLY IF you have backup-power tied directly to the Output. In these cases, rather than waste power / efficiency / regulation by adding a 2nd series, say shottky diode, on the output, you put up with the leakage.The circuit doesn't care, there's no AC mains to control. It can be designed "properly", but sometimes they don't care.

author: digsys
author_rank: Unknown
timestamp: October 06, 2012, 01:51:38 pm
content: Quote from: GEuserLOL, cross posted again :-)Of the schematic. I am a bit confused as to what the AC Trigger cct does. J3? bottom left. Timebase? AC fail early warning sense?Probably not important.

author: digsys
author_rank: Unknown
timestamp: October 06, 2012, 01:55:08 pm
content: Quote from: GEuserThanks a lot for the link, but my NOD A/V has flagged it as "on a list of potentially hacked links". Do you know it to be safe?

author: digsys
author_rank: Unknown
timestamp: October 06, 2012, 02:11:06 pm
content: Quote from: GEuserYes, it's the DC regulation feedback. The entire op-amp circuits feeding it are also "always on".QuoteIt's not important for this exercise. What you've provided has been very helpful. I'll do a google and look for another pdf source.NOD definitely does NOT want me to d/load from that site :-) Best I listen to it .. will update once I get further.

author: muvideo
author_rank: Frequent Contributor
timestamp: October 06, 2012, 02:24:24 pm
content: From a first sight to the PSU schematic, seem that R11+U1 should sink almost 5mA, and morethan 2mA trough R14-R27, and remains U4, probably somewhere around 1mA.That is the feedback circuitry from the flyback, I see no need to keep it powered while running on battery,let alone when unpowered. If I didnt made any mistakes, and if the pcb permits, a possiblefix could be to power U4 and U1 from a second rectifier connected to T1 pin 10 instead of D4that is always powered. Remains R14-R27, probably R14 could be disconnected from ground trougha small mosfet (2n7002 for example) with the gate connected to U4 power, the same can be donemore cleanly with a pfet that disconnects R27-R28 from battery when the psu is off.When my unit will be a little older I will try to mod it, it'sVERYannoying to find thebattery flat after few weeks, and if we let it unpowered for few monthes we risk also todamage the battery.Fabio.

author: aghp
author_rank: Regular Contributor
timestamp: October 14, 2012, 03:20:00 pm
content: Quote from: muvideo on October 05, 2012, 10:31:53 amThere is normal Lithium double cell's controller (afaik including balancing of course, hangzhou wanma is not whoever manufacturer) circuit inside battery module.(published picture do not show it, but sure it is "hidden" there)Also you know it shut off outputs after cells are under safety level. In this state it can only charge.In Finland I have onefullydisassembled battery. (It was manufacturing fail, so I use it for study.) After I'm back in Finland I can send picture to you if you are still interest.In China I do not have any disassembled battery.Btw.. I have thinked EEVblog is blocked inside China but surprice... today I get it open but nearly unusable becouse veeery slow..

author: muvideo
author_rank: Frequent Contributor
timestamp: October 14, 2012, 05:46:50 pm
content: Quote from: aghp on October 14, 2012, 03:20:00 pmOk, that's reassuring, it will be interesting to see the circuit.Do you know if the circuit posted here before is still the actualpsu/charger circuit? Or was it changed? It would be possibleto reduce standby current consumption.Fabio.

author: aghp
author_rank: Regular Contributor
timestamp: October 15, 2012, 02:03:55 am
content: Quote from: muvideo on October 14, 2012, 05:46:50 pmLast what I know: Old PS batt standby load was around 8mA +-?Newest PS what I know was around 3-4mA measured from single individual unit.Around 2000 hour. But then, also Li Cell natural self discharge reduce this some amount.My opinion is, old V reference current can reduce and also new can reduce still more. But is it really nessessary or where is some kind of balanced compromize?Of course if do more complex and clever PS it do not need at all this or it is meaningless.It need remember that many of us live in countries where is quite good powerlines but some may use it place where mains swing randomly from 0 to 240V and control need keep in hand in all cases in every second. But everyone can ask why it is 5mA and not 0.5mA.One extra switch is one nice solution. (if someone find different mains power switch what have extra contact for battery. (off position shut off also battery)

author: TomC
author_rank: Frequent Contributor
timestamp: September 30, 2013, 10:27:13 pm
content: Quote from: GEuser on September 18, 2013, 09:07:09 amI looked at your images and found datasheets that I think apply to the ICs on the board. Not exactly the same numbers but the ones on the board may be knockoffs. I attached the datasheets and a schematic I made based on your image and the datasheets. I believe the schematic is correct, but I couldn't see your images well enough to verify it for sure. I don't have the battery option, so, if you can easily gain access again to the inside of your battery, I would be grateful if you could verify its accuracy.

author: morgan_flint
author_rank: Regular Contributor
timestamp: January 03, 2016, 03:14:58 pm
content: Hello, I know the thread it's relatively old, but I'll try anywhere here because it's the place where I found more information about the Owon battery.Could someone post the battery dimensions (preferably internal)?The idea is to check if it would be possible to make a DIY battery for these scopes using standard 18650 cells (maybe 2S2P), so I need to know how many cells (if any) could fit in the package (I've seen in other thread the scope includes an empty battery package to cover the compartment).Looking at the schematic in the previous post, and also on post #32, it seems it could be doable with protected cells, or just unprotected ones installing a 2 element protecting board as the one in #52 (it looks like they'reeasy to find and cheap)

author: 1xrtt
author_rank: Regular Contributor
timestamp: January 04, 2016, 12:45:23 pm
content: I can't disassemble mine without destroying it, but the external dimensions are 109x109x29 mm.The specifications say:Li PolymerCell: 4669120/4000mAh/3.7vPack: 2S2P 7.4V/8000mAhI can't find where I bought it (Ebay keeps the records for two years only), but a quick search found this:http://www.ebay.com/itm/Owon-SDSBATTERY-8000MA-7-4V-Li-ion-battery-For-SDS-/191754824388?hash=item2ca57a6ac4:g:TBAAAOSw3ydVwnUNThe specified 4 hour charge duration may be ok for a new battery only, after almost 3 years, mine lasts 1 hour, so it stays plugged in and only use battery if really necessary.

author: morgan_flint
author_rank: Regular Contributor
timestamp: January 08, 2016, 12:22:59 pm
content: Quote from: GEuser on January 06, 2016, 12:09:33 amThank you very much for the info, and also thanks to 1xrtt.I can't remember the post where I saw the photo of the "empty battery box", but if find i again I'll post it here. Anyway, as the box's shape is fairly simple, it wouldn't be complicated to make one that fits in the compartment and then cover it with the supplied cover.I also had the doubt about if the slightly different chemistry between the original LiPo and the proposed alternative 18650 LiIon cells could cause problems with the charging circuits inside the scope, but from the schematic you posted (post#32 of this thread), it seems like the scope only provides a voltage at the battery port and all the care about charging is done inside the pack. Maybe the problem could be with the remaining capacity calculation, the different full charge voltages in both types could cause confusion, but I understand is a minor problem.What do you think?My questions about the subject are because I'm in doubt if I should buy scope+battery (about 50 euros extra) or just the scope and try to make the battery later with the cells from laptop's battery pack I have lying around (I don't have an urgent need for the scope's battery now, but I find it convenient).Another possible application is to revive old scope packs, as is the case of 1xrtt. I understand it will be difficult to find the original 4669120 cells wile 61850 are available everywhere.

author: morgan_flint
author_rank: Regular Contributor
timestamp: January 09, 2016, 02:15:23 pm
content: OK, I found the place where I saw the "empty battery box" used as battery compartment cover.It wasn't a photo, but a video:(watch from 7:00)EDIT: I found another teardown video:And, in this case, the cover is just a cover (no empty box)So maybe it's a matter of luck which one you get...EDIT2: Not a matter of luck; apparently from mid 2012 they don't include the empty box:https://www.eevblog.com/forum/testgear/review-of-owon-sds7102/2250/(Beginning of post#2250 and endo of post#2251)

author: Simon
author_rank: Unknown
timestamp: January 26, 2016, 09:22:57 pm
content: The quality of these things is awful. Yes the Earth lead falls off the socket very easily. If you have it open you might as well connect some wires to the battery compartment terminals ready for when the power supply board fails unless of course you intend using the battery.I have one of these and it lasted a matter of hours before the power supply failed so it now runs off a power brick.

author: Simon
author_rank: Unknown
timestamp: July 14, 2016, 05:49:09 am
content: what the hell for ? it all went quite and died on it's own and you are bring it back up to ask for it to be put to death??

author: BravoV
author_rank: Super Contributor
timestamp: July 14, 2016, 05:55:17 am
content: Fully understand its yours, you could do what ever you like.Why not just donate it ? Say if you don't want the hassle of shipping, packaging and etc, just make an ad in the buy/sell section for local pickup for free.My 2 cents.

author: TheAmmoniacal
author_rank: Unknown
timestamp: July 14, 2016, 07:10:10 am
content: Quote from: GEuser on August 06, 2012, 09:04:48 amPlease don't take this the wrong way, I'm just curious - you're flagged in Australia but your English is not very good. Why?

author: ebclr
author_rank: Super Contributor
timestamp: July 14, 2016, 07:19:18 am
content: It's amazing a difference a brain makesGuy with Brainhttp://blog.weinigel.se/Without

author: nctnico
author_rank: Super Contributor
timestamp: July 14, 2016, 09:43:59 am
content: Quote from: BravoV on July 14, 2016, 05:55:17 amThere are things you flush down the toilet because donating them would be inappropriate

author: wraper
author_rank: Unknown
timestamp: July 14, 2016, 10:45:01 am
content: Quote from: nctnico on July 14, 2016, 09:43:59 amDunno, for many folks receiving any entry level crappy scope would be a blessing.

author: wraper
author_rank: Unknown
timestamp: July 14, 2016, 11:28:56 am
content: Quote from: GEuser on July 14, 2016, 11:01:05 amDevices do not suffer, they are lifeless bricks. The only thing you made suffer is your wallet. Frankly, I consider people who smash their phones when they have a bad mood or do similar kinds of things, being stupid as minimum to one of the lowest form of life as maximum. Those who do this on youtube often are not idiots, they earn multiple times of the value of destroyed device because of the idiots who watch it.

author: Simon
author_rank: Unknown
timestamp: July 14, 2016, 04:31:29 pm
content: It's a crap scope but better than nothing, if it's that useless to you just give it away it will be better than nothing to someone. I have a 200MHz one and all I can say for it is it's twice as fast as my only slightly cheaper but better quality rigol so may come in use one day.

author: Hydrawerk
author_rank: Super Contributor
timestamp: July 15, 2016, 12:13:12 am
content: I have a 1982's scope from USSR, it is called H313. I do not use it, but if I did not want it anymore, I would give it to some children or so. Video made by someone else.It is a lovely ugly duckling.

author: Gyro
author_rank: Super Contributor
timestamp: July 15, 2016, 09:53:42 am
content: Quote from: Simon on July 14, 2016, 04:31:29 pmIt's very hard not to compare and contrast.https://www.eevblog.com/forum/testgear/free-oscilloscope/

author: Hydrawerk
author_rank: Super Contributor
timestamp: July 16, 2016, 08:43:02 pm
content: Quote from: GEuser on July 15, 2016, 04:13:18 amSynchronization was probably shit on many of them, including mine and the one in the video.

author: EU1
author_rank: Regular Contributor
timestamp: August 02, 2016, 01:25:11 am
content: It rather looks like bad tunnel diode in the synchronization circuit.

author: StillTrying
author_rank: Super Contributor
timestamp: August 02, 2016, 02:02:23 am
content: Quote from: EU1 on August 02, 2016, 01:25:11 amNope, definitely an axe in the screen.

author: EU1
author_rank: Regular Contributor
timestamp: August 02, 2016, 09:23:26 am
content: I was talking about H313