Rigol MSO5000 Power Supply - Page 1
Forum section: electronics / testgear

author: Protegimus
author_rank: Contributor
timestamp: July 02, 2023, 12:02:11 pm
content: Hi, has anyone already put together a BoM for upgrading components in the MSO5000 PSU?Alternatively, any good quality images of the PSU board would be helpful. Appreciate they are gunked up.I've been through Dave's teardown pic's, unfortunately there's not much visible.Intent is to replace the CrapXon's with some high quality alternatives with the objective of improving noise filtering.Others have already completed this work on different models and noted improvements.

author: beatman
author_rank: Regular Contributor
timestamp: July 02, 2023, 04:00:11 pm
content: I have replaced all caps with Panasonic fc.is a mater of time the cap xones goes leaky.and I am sure the psu is more quiet with better caps

author: Protegimus
author_rank: Contributor
timestamp: July 03, 2023, 04:18:54 pm
content: Nice work beatman.Do you have a record of what was needed that you are able to share?Any disassembly tips?

author: beatman
author_rank: Regular Contributor
timestamp: July 03, 2023, 11:29:47 pm
content: Only remove the back cover and Wright the value from all capacitors to paper. mf numbers must keep the same.voltage can be little higher. when you have the new caps open again the scop unscrew the psu and careffuly to not damage the traces do the job.i hoppe you have the skills.when I see crapxones on device i replace as soon is possible

author: perseverance8
author_rank: Newbie
timestamp: July 04, 2023, 02:03:26 am
content: I too would like to have BOM for the MSO5K PSU, if I remember correctly the MSO5K' s PSU's enclosure is soldered on.

author: beatman
author_rank: Regular Contributor
timestamp: July 04, 2023, 12:08:57 pm
content: no it is not soldered.it is hold in place with 4 screws together with metal shield.once you remove the screws you need to pull the big connector from motherboard and there is one screw for the earth in mains input side that's it.on my device after the job is finished i stuck and one fat ferrite to the cables between connector and psu

author: Protegimus
author_rank: Contributor
timestamp: July 05, 2023, 11:36:32 am
content: Thanks for the additional information beatman.Any chance you still have your notes on what value and voltage rating Panasonic FC's you used?That would form an excellent base for the bill of materials.

author: beatman
author_rank: Regular Contributor
timestamp: July 05, 2023, 03:43:47 pm
content: FC or FR series is ok for the application.nichicon KYA Nippon LXZ alternatives do the job.one more note is to cut carefully the white glue that hold together the old caps.and with nozzle plier remove the pieces.as I said before by the same mf and same or slightly bigger voltage.all is a matter of space bigger caps Don't fit.so check dimensions before you order.

author: Protegimus
author_rank: Contributor
timestamp: July 07, 2023, 07:17:27 am
content: Made some progress on this.Nice to see our MSO5000 is well constructed, disassembly is a breeze. Four torx T10 screws (highlighted yellow in image PSU connectors & screen screws) to remove the screen and PCB.Undo the five connectors and the board is out (image PSU connectors).BoM also attached in excel format with suggested replacements & other information.

author: Protegimus
author_rank: Contributor
timestamp: July 07, 2023, 07:21:11 am
content: Attached image showing additional bypass capacitors installed.

author: Protegimus
author_rank: Contributor
timestamp: July 07, 2023, 07:29:31 am
content: and PSU PCB with partial component overlay.Required components list is small for the MSO5000 (full details in the BoM)11x 1000uF 16V low ESR, e.g. Panasonic FM/FC/FR suitable4x 470uF 16V for these I selected KEMET A750KS477M1CDAE013 aluminium organic polymer capacitors (recommended by someone that has completed recap on other Rigol models)plus the additional TDK EPCOS metal film 0.1 & 0.01uF bypass capacitors if you wish.C1 is already Rubycon CXW 150uF 450v andC4 Rubycon YXJ 47uF 50vso nothing to be done there. I also bypassed C1.

author: Protegimus
author_rank: Contributor
timestamp: July 07, 2023, 07:37:43 am
content: CrapXons removed and replaced.I gunked them up again as per OEM to prevent vibration.Will do the remaining caps once I receive inventory.Can anyone identify U4 & U11 markedL2107?I have lots more images if anyone is interested.

author: Sighound36
author_rank: Frequent Contributor
timestamp: July 07, 2023, 08:21:17 am
content: This is an excerise I performed on the MSO 8000 & RSA5065 about three years ago they use the same SMPS unit.Definiately a worthwhile excerise especially on the spectrum analyser, I also went further a few months later, however I didn't change take any further images sorry about.

author: ballsystemlord
author_rank: Frequent Contributor
timestamp: July 07, 2023, 06:51:00 pm
content: Quote from: Protegimus on July 07, 2023, 07:29:31 amI only count 9 1000uf in the BOM. Which is it?Also, the originals don't appear to be low ESR. Is there someone who tested and found that low ESR caps work better or is this more because you can?Quote from: Protegimus on July 07, 2023, 07:29:31 amWhy bypass capacitors? Maybe you've read someone else's work that goes into detail on these matters which you could link?Thanks!PS: I'm asking because I own an MSO5000.

author: ballsystemlord
author_rank: Frequent Contributor
timestamp: July 07, 2023, 07:57:32 pm
content: Even more interesting, why bother replacing all those capacitors if you could just place a few on the output stage to filter the PSUs natural noise level?

author: beatman
author_rank: Regular Contributor
timestamp: July 07, 2023, 11:42:49 pm
content: I thing bypass caps is for audio big capacitance capacitors to get more quick charge discharge

author: Protegimus
author_rank: Contributor
timestamp: July 08, 2023, 06:16:29 am
content: CapXon KF datasheethttp://images.100y.com.tw/pdf_file/05-CAPXON-KF.pdf.Panasonic FM better the specification of the crapxon part in terms of low impedance characteristic (and pretty much every other specification), datasheethttps://www.mouser.co.uk/datasheet/2/315/ABA0000C1018-947496.pdf.Panasonic FR and KEMET A series are also classed as low impedance parts with suitability for use in PSUs, again bettering the specification of the crapxons. Sighound36 has generously already shared his positive results. If you can find improved alternatives that fit, then please post your recommendation and references.Addressing the question of why bypass. Take a look at the attached PYJD_PB0575_V1.00 bypass capacitors_02 image.I've highlighted red C12-C16 ceramic SMD capacitors Rigol fitted for the same purpose, i.e. additional noise filtering.I've just taken that further and also bypassed on the first part of the CRC filter, whereas Rigol implemented it on the latter. Capacitor values set the corner frequency for the filter, hence the use of additional values.Yes, the methodology is extensively utilised in high quality audio equipment.Fesz Electronics has some excellent videos, including a series on decoupling capacitorsCan we leave it at that re bypassing so as not to lose focus on the PSU. It's up to you whether you want to implement it and if you want to start a detailed discussion you're free to open another thread.Also attached is the updated BoM v0.2Not all components are fully identified, e.g. CS1, as some of the PCB silk screen is obscured by gunk. It's a work in progress, amendments/corrections are welcome.

author: Protegimus
author_rank: Contributor
timestamp: July 08, 2023, 09:11:00 am
content: Additional information on disassembly available in the MSO-5000E manual available here:https://www.rigol.eu/Public/Uploads/uploadfile/files/ftp/%E6%96%B0%E8%B5%84%E6%96%99%E5%BA%93-%E5%90%AB%E6%89%8B%E5%86%8C%E5%9B%BA%E4%BB%B6%E8%BD%AF%E4%BB%B6/%E5%AE%98%E7%BD%91%E8%B5%84%E6%96%99/DS/%E6%89%8B%E5%86%8C/MSO5000-E/EN/MSO5000-E_ServiceGuide_EN.pdfMSO-5000E limited 2 channel 150MHz bandwidth version, but chassis is the same.

author: ballsystemlord
author_rank: Frequent Contributor
timestamp: July 08, 2023, 01:06:56 pm
content: Quote from: Protegimus on July 08, 2023, 06:16:29 amThanks for getting back to me.I wasn't trying to take the thread some other direction. Just understand why you made the decisions you did. Being a student, there's still a lot IDK about electronics.

author: tautech
author_rank: Super Contributor
timestamp: July 08, 2023, 08:47:30 pm
content: Quote from: ballsystemlord on July 08, 2023, 01:06:56 pmThinking they know better than designers.Nothing wrong with CapXon caps when design and application meets their spec.Never had any issues with them in gear we sell in 10 yrs.Don't believe all that is spouted on forums.

author: beatman
author_rank: Regular Contributor
timestamp: July 09, 2023, 08:34:26 am
content: i disagree.companies cut cost everywhere.see the prices from capxone samwa samxon etc.i do repare and i own mainly a lot stuf audio amps processors etc you can see inside of 3-4000 euros device the cheapest crap.this is unacceptable.in most cases 85C temp. all the time found on psu's (any kind of psu's) audio household pc's no more than 7 to 10 years old this crap deformed or leaked.never sean good brand capacitor goes bad that way.i do a lot measurement before and after replace (crap)acitors in relative new devices in most cases the ripple and noise get a lot better.

author: 2N3055
author_rank: Super Contributor
timestamp: July 09, 2023, 10:03:42 am
content: Quote from: beatman on July 09, 2023, 08:34:26 amThat is why you took out capacitors that are rated for 105°C? Because some random PCs had bad 85° capacitors 10 years ago?Also, this power supply is basically a preregulator. Board has dozens of local regulators thatarecritical to signal integrity. If anything, those should be made "better". But to do so would need some real engineering, probably a respin of mainboard and would also be a point of diminishing returns, because other types of signal integrity problems would influence signal more (ground paths, crosstalk, shielding..)...And then you have noisy front-end/ADC on MSO5000 that drowns any other interference in it's own noise floor..It is basically a audio-foolery type of nonsense. Let's change all the capacitors for most expensive ones because "the more - the betterrer" ((c)AvE)..Let's see measurements before and after. Then we can see if it was worth it. So many of poor souls that do not have enough knowledge can realize it was a bad idea to disassemble perfectly working instrument (with maybe warranty) and possibly even damage it (Murphy never, ever, sleeps) to gain absolutely nothing. Except hand waving and woodo.Or maybe it is not woodo. Maybe it was worth doing it. Easy to settle: lets see what oscilloscope measurements got better as opposed to original PSU. Hard numbers. Like: RMS and P-P noise on 4mV/div was xx RMS and xx P-P and now is 1 or 10% better. Or in FFT you can see that spurs at xx MHz are xx dB down ... Those kinds of things.Or maybe statistical analysis of MTBF and defect rate on these PSU based on full battery of thermal tests in environmental chamber of say sample of 100 ?Here's one data point for you: there are literally 10s of thousands of those sold and there has been few years now. Not to mention all kinds of similar PSU designs by same manufacturers for other scopes... And you know what ? There has been practically ZERO defects on PSU for reason you stated.Oh, there were (expensive) Keysight scopes with PSU problem, but even those were not because of capacitors...Or only metric that it got better is that now you "experience the clarity of waveform presentation with nice and crisp peaks but subdued curvature of low frequency spectra and better defined pixel presentation of fine details..."

author: Protegimus
author_rank: Contributor
timestamp: July 09, 2023, 10:44:04 am
content: Now that experts have joined the conversation it seems like a good time to post before and after measurements.I was actually waiting until I'd completed the operation to make a better assessment (waiting on replacement Panasonic 470uF 16V capacitors), nevertheless ...PVP2350 probe grounded to the scope calibrate groundbefore - MSO5000_OEM noise 1mV 1ms 20MHz_filter screenshotafter partial replacement -MSO5000_partial noise 1mV 1ms 20MHz_filter ave 4be aware firmware was 00.01.03.02.02 at the time of original measurement, current is 00.01.03.03.00.With regard to the comment about, "Thinking they know better than designers". Little ironic considering they make money plying their wares from the forum EEVBlog which is based around Dave's critique of equipment design and implementation.Pretty sure you don't have to look too far in the teardown videos to find comment on use of low quality components...In terms of the PSU being a pre-regulator and that there is additional regulation down the line. Well that may well be so, but regulators regulate, it is the filter components that reduce noise.Reducing noise at source in the dominant switched mode power supply source will provide benefit which is all we are addressing here.Gents, if you can't add anything in terms of engineering or recommendations, don't post your emotive responses to trash this thread - make your own.

author: 2N3055
author_rank: Super Contributor
timestamp: July 09, 2023, 12:19:08 pm
content: Quote from: Protegimus on July 09, 2023, 10:44:04 amWay to be an ass....So you basically created controversy on purpose, baiting responses, instead of starting with propper "I had an idea, performed an experiment and measurements proved it was worth it"...Did you by any chance performed frequency domain analysis so we can see what frequencies got attenuated ??And I consider that filtering IS part of PDN.... Probably few well placed SMD capacitors placed on mainboard PCB locally would be even more gain... Also why did you place TH film capacitors across the elcos instead of ceramic SMD capacitors closer to output, or closer to high current paths to minimize current loop length.. Was there measurable difference with that placement? Did you try to put more filtering stages between PSU and mainboard?Please tell us more. Educate us..And yes, with MSO5000 FW version is a big deal. They have restored 500 uV/div in last FW because they have been something in their ADC algorithm lately, actually squeezing a bit less noise. That is why I asked for frequency domain measurements, to be able to see if decrease in RMS is wideband noise or discrete spurious tones...

author: beatman
author_rank: Regular Contributor
timestamp: July 09, 2023, 12:45:14 pm
content: That is why you took out capacitors that are rated for 105°C? Because some random PCs had bad 85° capacitors 10 years ago?Also, this power supply is basically a preregulator. Board has dozens of local regulators that are critical to signal integrity. If anything, those should be made "better". But to do so would need some real engineering, probably a respin of mainboard and would also be a point of diminishing returns, because other types of signal integrity problems would influence signal more (ground paths, crosstalk, shielding..)...And then you have noisy front-end/ADC on MSO5000 that drowns any other interference in it's own noise floor..It is basically a audio-foolery type of nonsense. Let's change all the capacitors for most expensive ones because "the more - the betterrer" ((c)AvE)..Let's see measurements before and after. Then we can see if it was worth it. So many of poor souls that do not have enough knowledge can realize it was a bad idea to disassemble perfectly working instrument (with maybe warranty) and possibly even damage it (Murphy never, ever, sleeps) to gain absolutely nothing. Except hand waving and woodo.Or maybe it is not woodo. Maybe it was worth doing it. Easy to settle: lets see what oscilloscope measurements got better as opposed to original PSU. Hard numbers. Like: RMS and P-P noise on 4mV/div was xx RMS and xx P-P and now is 1 or 10% better. Or in FFT you can see that spurs at xx MHz are xx dB down ... Those kinds of things.Or maybe statistical analysis of MTBF and defect rate on these PSU based on full battery of thermal tests in environmental chamber of say sample of 100 ?Here's one data point for you: there are literally 10s of thousands of those sold and there has been few years now. Not to mention all kinds of similar PSU designs by same manufacturers for other scopes... And you know what ? There has been practically ZERO defects on PSU for reason you stated.Oh, there were (expensive) Keysight scopes with PSU problem, but even those were not because of capacitors...Or only metric that it got better is that now you "experience the clarity of waveform presentation with nice and crisp peaks but subdued curvature of low frequency spectra and better defined pixel presentation of fine details..." i don't say to everybody change the capacitor.the cut cost by companies is a fact.you can't compare cheap cap with brands like panasonic nippon nichicon etc in performance and life.the specs on paper are warranty.every single audio device changed capacitor or better bridge or diode sound much better and is a fact. usually i measure every (old) capacitor for mf and esr and out of the box the device have 30-40 procent down capacitance!!!in mass production save money is mandatory.only imagine what chinese crap smd is installed to everything and not everyone can see or meassure.i don't say to use extreme hi end or military components is not for everyone and the most of them is snake oil.only better good quality instead the standar bottom category.see (badcaps forum)what capacitors goes bad.

author: Protegimus
author_rank: Contributor
timestamp: July 09, 2023, 02:29:49 pm
content: Gents, please don't respond to the threadcrappers any further here. They have an agenda and that has nothing to do with improving the MSO5000 PSU.@2N3055 directly - your hysterical statements and the over complication that you seek to use in order to support your claims is laughable. I didn't come here telling people what to do, nor am I ruining my credibility by making personal insults and being passive aggressive.I'm glad Rigol have continued to make improvements to the firmware, increases the scope of what the tool can be used for. If you want to take measurements that help identify what's been done; great, go do them, but do it in your own thread. I deliberately didn't publish measurements using the 500uV range, although I do have screenshots.It's a simple low pass filter and yes it's possible to improve the performance of a low pass filter. As pointed out Rigol already bypass the 470uF capacitors, we are simply doing the same. Using SMD could offer improved results, nothing to stop you using SMD if you prefer.

author: 2N3055
author_rank: Super Contributor
timestamp: July 09, 2023, 03:19:34 pm
content: Quote from: Protegimus on July 09, 2023, 02:29:49 pmSo what is your agenda ??

author: beatman
author_rank: Regular Contributor
timestamp: July 09, 2023, 04:05:44 pm
content: 2n3055 have you ever made test's? I mean measure components or acoustical test temperature test or sound analysis? i do all the time for years and I see only positive results when is something better soldered on circuit. we don't push here nobody to do anything only we tell our experiences the guy open the thread ask for something and get answers.one example here expensive pro power amplifier with main smps filter capacitors Daewoo brand one of them leaked.for me is unacceptable.replaced with kemet.the amp now it sounds fantastic on subwoofers.low tier caps is not for stressing things like smps.is a mater of time to goes bad

author: TurboTom
author_rank: Super Contributor
timestamp: July 09, 2023, 07:19:44 pm
content: Maybe, after the re-capping job, the scope's fan sounds better...

author: Protegimus
author_rank: Contributor
timestamp: July 10, 2023, 06:35:55 am
content: With the foolery now out of the way let's engage on some of these ideas. Seems looking at ways to improve the PSU wasn't nonsense at all.Quote from: 2N3055 on July 09, 2023, 12:19:08 pmNo I was previously thinking in simplistic terms of DC output rather than targetting filtering.I may do this when I next open the unit to see where it's at.Quote from: 2N3055 on July 09, 2023, 12:19:08 pmAgreed. One step at a time though - it makes sense to address the PSU first as the root, improving output quality there benefits everything down the line.Quote from: 2N3055 on July 09, 2023, 12:19:08 pmRigol already decouple all supply rails with ceramic SMD capacitors on the output C in the CLC filter:They were not fitted on the input side close to the rectifiers.J5+5V - C16-7V - C15+7V - C12J4+9V - C13+7V - C14+5V rail on J5 appears to be the high current rail as it has two pins on that connector.Appreciate the suggestion of using SMD instead of thin film. That may offer some further improvement.Quote from: 2N3055 on July 09, 2023, 12:19:08 pmNo. I like the simple approach.Quote from: TurboTom on July 09, 2023, 07:19:44 pmYou should try staying quiet

author: Sighound36
author_rank: Frequent Contributor
timestamp: July 27, 2023, 01:48:55 pm
content: All I'm going to say on this matter is Crapzone caps would come no where near my own designs. Cost is the first and for most use of this brand imho. If you are purchases 100K or Millions of these the cost per unit must be rather appealing. I'm back to my hum drum life now

author: BRZ.tech
author_rank: Regular Contributor
timestamp: September 23, 2023, 07:57:15 pm
content: Hi.I liked @Protegimus' suggestion of adding polyester capacitors to the primary and secondary SMPS of the MSO5000.The effect of drastically reducing the NOISE FLOOR was excellent, from 202.93uVrms to 67.715uVrms, on the 1mV scale, remember that this scale has the BW locked at 20MHz, see the “B” on the 1.00mV side.The NOISE FLOOR reduction was 66.63%. This, in terms of NOISE FLOOR, elevates the MSO5000 to a higher level of quality.One detail I noticed is that in the Excel BOM, the 0.1uF/200V and 0.01/200V capacitors, in parallel with C1, have insufficient insulation, the voltage there can reach Vp>340V. I suggest, in those positions, 630V isolation.I also verified that a 10nF/J/400V polyester capacitor was added, in parallel with CS5, which is the +5VDC voltage output.My suggestion is to add a 10nF/J/400V capacitor in parallel with the CS1 capacitor... You can keep the 10nF/J/400V capacitor, in parallel with CS5, without any problems. (see the photo).Maybe the NOISE FLOOR will decrease a little more.In my opinion, the topology of this MSO5000 SMPS is Fly-back. With the IC-U1 controlling the PWM and the TR POWER MOSFET, which does not have silkscreen on the board.I also verified that the soldering of PTH components are not excellent. The suggestion is to carry out a welding review of these components, with a soldering station at 480ºC, and good quality solder.Request: if anyone has already reverse engineered this MSO5000 SMPS, please post the circuit here in this topic. Identifying the name of main components such as IC-U1 and POWER MOSFET.As soon as possible I intend to do this update on my MSO5074.

author: Protegimus
author_rank: Contributor
timestamp: September 25, 2023, 08:39:26 pm
content: Thank you for reviewing the updates and posting the recommendation for increasing the component rating.Good to see the improvement was repeated.

author: thm_w
author_rank: Super Contributor
timestamp: September 25, 2023, 10:57:04 pm
content: Quote from: Protegimus on September 25, 2023, 08:39:26 pmThey are just quoting your numbers, they haven't actually done anything yet.

author: Protegimus
author_rank: Contributor
timestamp: September 27, 2023, 02:37:34 pm
content: Good spot, jury is still out then.

author: Protegimus
author_rank: Contributor
timestamp: March 31, 2024, 09:09:39 pm
content: Quote from: BRZ.tech on September 23, 2023, 07:57:15 pmQuick note to say that CS2, CS3, CS4 and CS5 are all on the +5V rail. Taking the suggestion from earlier in the thread I've ordered KEMET C0805C104J1REC7210 Multilayer Ceramic Capacitors MLCC - 100V 0.1uF X7R 0805 5% X7R SMD capacitors to bypass these just as Rigol have done with CS9, CS12, CS15 and CS21 but not yet had the scope open again to fit them.CS1 is actually between the anode/cathode on one side of DS1 the JH SRF2060C Schottky barrier rectifier diode (DS2 & DS6 also have the same 26R1 resistor and cap, to damp switching noise?).Attached image has the additional components marked up.

author: BRZ.tech
author_rank: Regular Contributor
timestamp: April 14, 2024, 02:51:21 pm
content: Hi,Dear @ProtegimusYou are right about the CS1 capacitor. See in my post #31 the marking I made in the position in the image I sent. Note that the CS2 (electrolytic) capacitor was without the silkscreen, and you added it to your message, in message #35. Correct.Therefore, my suggestion is to place the 10nF/J/400V capacitor in parallel with CS2 (electrolytic), on the solder side. This will maintain the logic of your brilliant article.Here in my country I managed to buy TDK 10nF/J/400V and also 630V polyester capacitors. But PANASONIC brand electrolytic capacitors are not available here, and to import them, the legal taxes and shipping are astronomical and unfeasible. I won't change them for now.I also intend to place an extra 12VDC cooler, to blow the heat generated from inside the case to the outside, over the SMPS heatsink, to help with the internal ventilation of my MSO5000. I will put between the Voltages (+7V and -7V), which will give a total between them of 14VDC. And insert there (3x 1N4007 diodes) in series with (+7V), to give a drop of 3 x 0.7 = 2.1VDC. To maintain the Cooler voltage specification at 12VDC.In my country, temperature and humidity variations are very high, and on days with temperatures above 30 degrees Celsius, the inside of my MSO5000 heats up too much.I have already placed the new cooler outside the case, with an external 12VDC source, and the results are good, the internal temperature drops a lot. Without the new fan, sometimes the CH2, CH2, CH4 channel inputs are activated randomly, without the external cooler.I hope to soon complete the entire procedure and list the results here.I haven't opened my MSO5000 yet. It is now out of Factory Warranty. I have already defined what to do to install the polyester capacitors, and how to attach the new Cooler.I am very grateful for your commitment.

author: ballsystemlord
author_rank: Frequent Contributor
timestamp: July 17, 2024, 12:23:00 am
content: In hopes of getting a lower noise floor, I wanted to try and upgrade my scope's PSU as well.No one seems to have mentioned that Rigol conformally coated the backside of the PSU's PCB. I'm not sure why they did only one side of one PCB.Anyway, I'm not sure what I'll do here. My guess is that they had problems with arcing from mains (Yikes) or maybe some sort of coupling to the metal case which is grounded. Hey, they saved money by using CapXons, so there's no way they would have gone spend happy on a conformal coating without a reason.I'm not sure what I'll do at this point in time. It might be just as well to roll a linear PSU and test that.PS: It's not obvious from other people's photographs, but the TO-220 packages do not have any part numbers on them. It's not that they were rubbed off, the part numbers are just plain missing. They're probably a really low end Chinesium type.