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- Опубліковано 28 чер 2024
- In this episode Shahriar investigates a failed Rohde & Schwarz AFQ100A I/Q (ARB) Modulation Generator. This instrument provide differential I/Q outputs with exceptional SFDR which makes it ideal for various wireless system testing. The instrument shows a stand-by LED but does not power on.
The problem is tracked to the main power supply's soft power-on circuit. After the repair of the power supply, it becomes clear that the main HDD is also defective. An identical donor drive is used to repair the broken HDD main controller board. A full teardown of the instrument is also presented. After the repair, the instrument is used to generate various arbitrary waveforms for performance verification.
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26:50 we did! 🤗thank you for taking the time to show us!
Worth to note for readers - often replacing boards from different hard-drives quite dangerous, as firmware can have different settings and mapping, which are not matching the platters side, even from same model drive. So there is high risk to bork everything beyond repair by doing controller board swaps. Glad it worked out in this case.
I made sure the firmware is the same version. This is all listed on the drive itself.
@@Thesignalpath Firmware is only one bit of the story, service information and maps also stored on media.
Agree, the bad sectors are stored on the board for instance... swapping the EEPROM from the bad board to the good one is likely what is required.
@@xDevscom_EE Yup this, must admit I was a bit surprised it worked without errors. Got lucky.
Wonderful and very educational video as always. Thanks Shahriar!
One of the best youtube channel. Like your video so much.
That R&S computer is a standard part, that R&S calls FMR6. There are several versions of the computer in this formfactor. It is universally used across many instruments, such as the CMU200, CRTU, likely even ZVL and FSP etc...
Ah, pardon, this is not FMR6, this is the more recent stuff with SATA interface, likely FMR7? I think 6 was the last one without SATA.
But can it run Doom?
At 15:11 BIOS says FMR7
@@benmodel5745 I'm pretty sure Doom would be a walk in the park, it's from the 486 era after all. Crysis is another matter.
I love that fancy heatsink design on the underside. Very cool.
Perfect, As always
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Absolutely brilliant video. I particularly like the hard disk repair which you treated very casually, but to everybody else would’ve represented an entire video. Great work.
Brian Frost , Funny you put it that way, too!
Nice repair and video! My humble thanks.👍
I'm really happy you got that drive to play nice on the first try! That could have gone either way. Nice instrument to bring back to life.
Rohde & Schwarz hardware never disappoints. Top notch.
Interesting and informative video! Thanks.
I would really image that HDD quickly now you got it working and put a new SDD in place of it , before it goes pop and you loose the lot :)
I'm pretty sure Shariar will have the HDD image file saved using something like dd on his NAS, cloud storage or even a USB thumbdrive. There is no rush to SSD.
@@Drew-Dastardly LOL - Yep, but NOT done similar things myself and spent days and money getting images from suppliers that i didn't need to do if i had just done what i have said :( I always back up now at the first chance, as i do alot of CAD CAM machine repairs and it very easy to either loose, or delete the data :( :)
Yes you are right, the very first thing I did was to image the drive. :)
Great repair. Before changing platters it's worth changing hdd firmware chip on an identical board
Always the electrolytic -- except for when it's not! Check out the fan as well, could be why the PSU got toasty in the first place.
Really enjoy the videos, many thanks.
Had the same issue in an R&S ZVA network analyzer power supply, also a high quality Lambda power supply with a failed cap in the startup circuit. Also had a „burned“ loe voltage power connector in a R&S SML signal generator...
Sophisticated RF instrument.. still struck down by run-of-the-mill power supply and disk failure! Just like a $175 laptop from WalMart. Very nice walk-through of the instrument, thanks very much. I missed Pooch - out on vacation this week?
Pooch was on his sabbatical this week! ;)
@@Thesignalpath , LOL!
A very good video.
Shahriar, You Da Man.
>open the hard drive and switch the platters
WAIT WHAT
Just do it in the shower to keep the dust down. :)
Just the THOUGHT of doing that makes spots on my little undershorts.
It isn't that bad as long as you do it in a reasonably clean environment and clone it sofort (i.e. with Germanic immediacy).
I've done it twice in my life and it has worked, in a non clean room environment. If it's your last resort, either the controller or motor and you need that data.
@F. BERTAGNE A good data recovery company is the right way to go if you have things you might not want to risk losing, but like you said, not cheap. Thanks!
Smashed like button. thanks !
other companies: Just put a proper heatsink on a hot component
R&S when they notice a heatsink is too small: We shall make a giant airflow shroud! Out of solid metal!
...but leave the poor outsourced power supply to suffer its own thermal agony :-)
Brendon Bentley pure german engineering, engineer everything brilliantly, ensure something breaks in time
@@sunnohh It is doubtful that the design intention was to ensure that something breaks in time. There are principally two risks with outsourcing any hardware block. Firstly is poor integration which usually results from misunderstanding the outsourced portion. This misunderstanding comes from poor documentation by the manufacturer of the outsourced block or expectations/assumptions by the integrator that deviate from reality. Secondly the manufacturer of the outsourced hardware may not put the same care and emphasis on quality (often driven by business level/company culture considerations) that the integrator expects. This is not always simple and easy to detect, verify, document & enforce. For these reasons it is seldom a good approach to outsource anything. If saving development time on an outsourced power supply is valuable, then go for it. But please do go back and do your own power supply at the end to be in control of your own product. Power supply failures account for most electronic failures and may even cause more damage down the line. Perhaps the hard drive in this video failed as a result of the power supply? (...because it is seldom to find two independent failure modes on a broken item.)
@@asm2750 I had the chance to select what kind of instrument I need for my job and I picked FSW85 (2Hz to 85GHz) spectrum analyzer, my former employer bought it. In the end I regretted my decision. The RF performance meets with it's price tag, but the GUI is buggy and can poorly operate with the connected RT2064 sampling scope.
As you suspected, the motherboard is a common design for a lot of their instruments, from early Pentium III based designs up through Windows 7 machines, at least. In some units its internal, and in some it's directly behind the display, and they're largely interchangeable, though the front panel decoder chip is coded to the kind of instrument its part of. That white flat flex connector on the left side when first opened would normally be for the front panel buttons, while the shrouded 0.1" connector above it would be for the front panel encoder knob. The IDE port you suspected is actually a secondary display connector, the smaller one next to it is used on more modern instruments, whereas the 0.1" IDE port looking one is the older panel connector.
It seems like every one of these boards has that ethernet port jumper, a goofy addition when you have so much backplane connector space, but I guess they couldn't fit it. I've seen this format board in all sorts of instruments, the CMU200, AMU200, SMJ, UPV, and a few of these units with no screen or local controls included - I think almost all of their rack sized equipment in this same era used these control boards.
Mazing.
Forget about exams when there's an RF video
You’re starting to see that type attenuator that uses relays in audio equipment. They’re trying to achieve better linearity than a pot. But I always wonder that the contact resistance in the relays doesn’t change over time and change the attenuation. Or maybe they’re solid state relays?
Could you show in one video the EPM6600 used for power measurement in this repair?
Great videos as always, looking forward for the next one.
Same request here
Great video! After replacing the PCB of the HD, normally you would have to swap the firmware-chip to in order to function correctly again?
I made sure to get an identical HDD with the same firmware revision. This is listed on the HDD itself which is great.
@@Thesignalpath Not just the firmware is important, specific drive parameters (e.g. bad tracks, alignment info) are also stored in most drives. Therefore one should exchange the chip, although just for reading it make work for a while.
The Firmware is available online, the changelog says it includes some "USB drivers" so there's a chance it also includes other necessary drivers to communicate with the sig-gen hardware...
www.rohde-schwarz.com/firmware/afq100a/
You could try to install a blank Windows XP Embedded, then install the firmware on top.
PS: With an SSD, you should try to set it to AHCI mode instead of IDE in the BIOS and make sure to use an SSD that explicitly states it has software/drivers for Windows XP. Sind WinXP does not support TRIM natively, you need a mnfg tool that clears old data from the SSD periodically or else the SSD will likely be slow (depending on capacity). Also disable defragmentation.
actually all modern hard drives has serial terminal interface similar to linux boards. it is possible to see errors in post messages or run some test or specific commands.
Interesting!
Shahriar, between 20:26 and ~22:00 you mention an acronym DRO multiple times. Please excuse my ignorance - does this stand for dielectric resonator oscillator?
Yes it does.
Damn, $60K for that R&S scope (RTO2064). She's a beauty, though. I'm not even qualified to use it, but I know good quality when I see it. ;)
Nice. I notice an NGM202. Can you review the battery simulation capabilities of this unit? Thanks.
Sure, it is on my list.
@@Thesignalpath Thanks alot Shahriar. I'm wondering what actual instantaneous dynamic range for current measurement is possible... ie. if an IoT device is deep sleeping in the nA's and wakes to pull 100's of mA's... will the unit support/log this fast dynamic auto(?) ranging and provide accurate capacity estimates of what the DUT is demanding. Are there hi-speed switched/banked shunt resistors(?)... etc.
I am such a R&S fanboy, own the older AMIQ.
Hi, I would like to see your professional opinion on more cheaper, affordable units like NanoVNA v2, Malachite SDR, Limesdr, RF Power Meters from Aliexpress...
Thank you
Hey did you ever test if you can upgrade the sample memory of your RTO2000 scope?
Also I would love to see a teardown as I could not find any teardown of this scope.
I'll try to do a teardown. It is a really nice instrument.
Impressive R&S stack. Great to see one of these devices dissected and repaired. It's somewhat of a surprise to find out these machines are pc's - and running windows at that. One would probably be forced to go that way in our day and age but I was hoping that R&S would choose an open source OS or develop their own.
A rather mundane question: what are these telescopic legs you're using to prop up the shelves? they look too small to be from IKEA - can they be ordered from somewhere? It's a very neat solution to an ever existent problem.
Yes, they are Ikea. But discontinued. :(
@@Thesignalpath Typical - they usually discontinue anything worth making or they change it to a lower standard. Great idea nonetheless. When I saw them used this way I immediately thought they must be using the same mechanism as that inside shower a curtain rod. I've been racking my brain for years (pun intended) on what the ultimate solution for an adjustable hifi rack would be and I thought I found it when I saw these. Alas, it's not to be.
Have you had a chance to use one of the Scope Riders from R&S? I've seen your Spectrum Rider but we've got one of the Scope Riders at work and it's an amazing piece of equipment; it's like a more powerful RTB2004 inside a portable body with fully isolated channels. It might be a good addition to the R&S selection if you can get ahold of one!
No I don't actually have one of those in the lab. Looks interesting. You can always ping R&S that you'd like to see a review on my site for the instrument. :)
Shahriar could you advise? For my DIY projects I need a spectrum analyser, and it seems that I can get for the same price used HP/Agilent 8594E (or similar) or a brand new Siglent SSA3021X PLUS. Which one is a better choice? The Sigilent comes with a warranty and is made using COTS components and it is smaller while HP/Agilent had got a good heritage.
At this point the Siglent will give you a lot more features and much better user interface. I’d go with Siglent.
That air flow guide is probably doubling as a shielding system to help reduce noise escaping from the power supplies.
Do you purchase all the broken equipment from Ebay or somewhere else?
Yes. Most of the time eBay.
Higher end RF stuff like this still tends to fetch a pretty penny on ebay tho.
Be sure to image that hard drive
🙏🙏🙏👍🙏🙏🙏
Yay, more RF stuff. Great.
LOOKIT THOSE TINY TINY RELAYS
i want to chew on one!
Seeint the R&S power supplies, I‘d really love to see you analyse an EEZ Bench Box 3 modular power supply. It‘s open source and targets a higher end market. I’d be even more interested in your opinion about the overall concept of an alternative, open source lab standard that it tries to create. github.com/eez-open/modular-psu
Sheer porn. :-9 I would love to know more about that EPM6600. Do you feel it is reasonably accurate? Would you have the means to do some verification on it?
It is a nice little unit to have on the desk during repairs, etc. I have not had any issues with it. Looks to be reasonably accurate.
Please consider switching back to your *plastic* pointer when showing us stuff on the boards, rather than the metal one. You certainly know how to do this safely, but sticking with plastic would be a much safer habit to teach your viewers who don't have anywhere near the experience you do.
Sure!
1:30 didn't you say it runs windows ? one minute bootup is kinda-sorta normal... 🤣
شهریار ،
Wonder why such high THD on these equipment, are they running outputs stage on class AB , or is it main oscillator, are they running oscillator in colpit configuration class A , it would be nice to get lower THD , and find out the main root cause for example is it crossover distortion or is it none linjre , are second harmonics or are they third harmonics, signal amplitude was not so high too.
At end you measuring with vector analyser , and you said it is spectrum analyser ! , it would be nice to have one video to show the difference between the equipment,
Greating from Sweden
The ZNL is a hybrid instrument; it is both a VNA and a spectrum analyzer. I am also measuring IM3 not THD. But either way, the results are normal. The AFQ is much better than what is measured. The RTO and ZNL instruments are not as linear as the AFQ which is to be expected.
yeah whoever installed that hdd bent the cable beyond any reasonable point. if i were you i'd replace the cable. I'd probably replace the hdd with an ssd, as well.
R&S really disappoints me with this instrument. Have they lost their proud and self-esteem, or should I say lost their minds? Integrating a power supply that has Jianghai capacitors on board is unforgivable!
If you pay a premium price, you would expect nothing but first class components. Not AliExpress turds.
The power supply is not made by R&S. It is made by Lambda.
@@Thesignalpath I'd have to say the same comment applies. Lambda is probably the most prestigious PSU OEM on the market. What you found on that board is some really weak sauce at their level of play.