TSP #81 - Teardown & Repair of an Agilent 54845A 1.5GHz 8GS/s Infinium Oscilloscope
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- Опубликовано: 6 сен 2024
- In this episode Shahriar repairs an Agilent 54845A oscilloscope with an intermittent failure. The instrument occasionally fails self-calibration and the displayed waveform shows undesired spurious activities. The teardown of the instrument reveals customized front-end section coupled into a ceramic-substrate ADC ASIC designed by Agilent. The packaged ADCs are placed in sockets. The ICs are removed and the ceramic carrier is cleaned; this resolves the intermittent problem with the channels. The architecture of the scope is also presented. The functionality of the scope is verified through self-calibration, self-test and measurement of various waveform.
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I doubt I would have considered that issue with the ADC's. Even if I did, not sure I would have the stones to pull it apart. Well done! Considering the architecture to build some intuition of the problem as step 1 clearly saved a ton of time chasing your tail. To some this may seem like an easy fix, but without the methodical approach to gaining intuition it could have been a total fail.
I would have like to got more info on the cleaning process and products used ?
Thanks again John
Thanks for another great video. Interesting how you immediately suspected the ADC connections. Considering the OS is WIN95,
I would have wasted a lot of time troubleshooting software. Thanks for another learning opportunity.
We use these at work, and I have such a love-hate relationship. So capable bandwidth wise and as far as measurements but such small memory depth. Asked for a new scope that doesnt run on windows 95, and got rigol 2000 series 70 MHz scopes :-/ So now I have the infinium and the rigol on my bench.
You got nice repairable unit again. One of things I wished to have - bit more details on cleaning process of such ceramic packages and pogo sockets. Those things are fragile and sensitive, so I'd assume regular "swipe stuff with IPA" may not work in such a case? Perhaps separate video on cleaning high-frequency boards and ICs would be possible in future? I'd expect same tecnique would apply today's technology as well.
+xDevs.com Yes! I wanted to see how he cleaned those pogo pins too! What chemicals? How abrasive? Please tell us!
Yep - me too ...
IPA doesn't affect ceramic or metal so.. wipe with IPA? Just limit mechanical stress
Wow I didn't expect the problem to be in the adc connections. Nice video.
This is a very interesting, instructive and compact video!The ceramic A/D hybrids were very impressive.Well done, go ahead!
AMD K5 wow, I suppose it was fast enough to get the job done and sensibly priced. Nice scope. Thanks for posting.
POOCH!!!!! :D easy repair. easy cleaning and re-seating Lots of lights and push buttons....Thats actually a really nice scope.
Pooch-spotting!
Pooch is in a few video's he/she has a knack for being around stuff that Needs to be repaired , if its minor pooch only hangs around for abit.then leaves. but if its something else pooch will hang around for abit.
+Amy Marie Its always a free cat scan!
+The Signal Path Blog Pooch some how Knew the RCL Unit needed to be repaired.
OMFG! 95 was the last Windows I used prior to switching to Linux. The password thing is required just so you can join a Windows network. No need to provide one since you won't be running NetBEUI / NetBIOS any time soon :D. Apparently TCP/IP and DNS have gained a bit more traction and quite a few computers tend to have it preinstalled nowadays :D
Well, Windows computers still use NetBIOS over TCP/IP for file&printer sharing.
You kids and your IPX/SPX back in my day we sent packets via carrier pidgin.
Hmmm, twice now recently you've turned something on without it being plugged in...heh, heh; I've never personally done that myself! Well, maybe I have...I sit there saying to myself "Self, why in the world isn't this thing turning on? Oh crud...that's why!" Thanks for sharing another informative video, keep 'em coming!
Wow those fans are loud. Good job. Good vid.
We don't say "different" now, we say " special "...and I'm sure it's mother loved It very much.
Please make some more stuff for us,, your fans are hungry.!!!
Good Job Shariar. I consider your channel the best on ee. I understand your new proposal for the channel and I liked it. Please continue!
Theoretical lectures such as on various rf components, synthesizers, communications, power supply, etc. or anything else you find interesting would be wonderful
Hmm video was good. I just missed that part with repairing those sockets or cleaning... I would not mind if i didn't see it on all channels but on that one channel it would be nice to see. Next time I could have similar problem so i would also want to see it how to repair it or what to do.. Soo that that was my small advice from me. Good job and make more videos :)
Agreed. I felt the actual cleaning process would could have made a substantial impact and improvement to the video. Instead I can only imagine what he did or why.
Oh I almost forgot: I have seen these modules near the CPU also on standard mainboards back then. AFAIK they were only necessary for certain CPU types that needed special voltages. There are capacitors near the CPU and also in the power supply that are a bit "mean". Which refers to: They do look perfectly fine but they are not. I had to replace some of them that lost about 30% capacity and also had increased ESR. They cause the aquisition and/or mainboard to lock up randomly (about once per hour), especially when the scope is warmed up.
Very nice repair video, those videos never ever get old. I wonder if those fans are supposed to be that loud or if their bearings are worn out. I think they are still ok, but at least on camera they seem to be very noisy.
Great video as always. Thanks for your time and effort putting these together.
Relieved to see I'm not the only one to feel so uncomfortable hard-powering-off a windows system in mid flight!
An oscilloscope I dream about. Great video!!!!!!!!!!!!!!!!!
Cool Vectron Crystal Osc.
I'm glad the repair was easy for you. While I hated the rats nest of PC cabling, the ADCs were gorgeous to behold. That whole UI is very dated, however. Am I being too unfair to expect better stability at the top-end of the bandwidth rating?
very impressive, but kindly explain if no cannel is detecting what should be the problem please?
Nice teardown! It's a big LOL when you see pieces of cake like this on Ebay in US. It's incredible how people doesn't even looks for a simple repair.
Could you guys gently speak more about RF? And I have a little doubt, when designing a RF PCB (for a transceiver, for example), is this correct to isolate GND and POWER signals between stages with beads like we normally do with Digital and Analog domain? Or make just a big GND plane and that's it, just separating the power (for the Power Amplifier) and low power signals?
THanks for the video. Good job.
Would using an active probe clear up some of the noise and jitter in the signal. Another great video again, Prince :(
you want to fix my circa 1974 cro it had a bandwith of 10mhz lol. Keep the great videos coming!
Shahriar, if you don't mind me asking, what figures did you use for the torque wrench/screwdriver? Where did you get these from (if from a manual etc?) ?
always great, thank you.
Great Video! Thank you!
It's safe to hard shut-down the Windows because it doesn't write much to the drive. (probably only the user settings) Parts of it are loaded into a RAM drive, and this is where most of the writes are happening.
That GPIB controller card has quite the flex to it... or is that just a trick of the camera?
Awesome video! As always!
Dammit. It is 5:00 in the morning. Too tired to watch and understand....:)
But here, get a thumbs up
Would it be worth getting an IDE SSD, or even a CF card to replace the HDD on something like this? I'd be really worried about the HDD failing given the age.
Does that 🐈 assistant you during fixes. It seems like it always wanted to take credit in front of camera.
Love the repair videos!
Plug-in VRMs used to be the norm with higher-end PC mainboards.
I love the repair videos...
what happened? where are you??
Excellent, Shahriar, Your video has been very useful to me! I have recovered the exactly same scope from scrap, and after fixing some caps on the PC side around the CPU, the windows started to boot!!! :). Similar symptoms with selftest though but the trigger issues you see at 1.5GHz already start at 1GHz on mine. Sometimes, cannot trigger at all, unless I do autoscale with lots of clicking of relays that usually fixes it. So I was suspecting some relays were at the end of their life... Since this does not happen very often, and under 800MHz it is quite dependable as as a "hobby scope" I did not have the courage to pursue the ultimate fix... You gave me some ideas, thank you!!! Did you happen to find a service manual by any chance?
I like your repair videos. This one was pretty simple (good for you, bad for us), so hopefully you can find some test equipment that has something besides a power-related issue. Those more in-depth troubleshoot/repairs are the most fun to watch. Seems like most of the power problems are just bad caps/bad regulators or a blown fuse. It would be fun to follow along where you actually need to bust out the oscilloscope and multimeter to troubleshoot the issue.
Thanks for the videos. I had no idea you had a PH.d. Im assuming you have a day job as well?
+Ron Berry
www.linkedin.com/in/shahriar-shahramian-41813912
www.columbia.edu/~ktj2102/CISL_D/Seminars.html
Hehehe, I really want to see a SSD upgrade for one of those. :)
Those hybrid acquisition modules sell for about $350 apiece nowadays.
Sorry for dummy question but what is wrong with these HP asics? Who is manufacturing them? Where are some datasheets?
I am asking because i have seen them so many times and i absolutely has no informations about them. Is it same HP company as HP we know from personal computers (Hewlett packard enterprise)?
Great Half-Life 2 reference!
How did you clean around the pogo pins and pads?
First of all, nice video again.... Wow, "embedded" Windows 95 hahaha ;)I am not sure if this makes any difference, but you have been closing the acqusition dialogs by clicking on "X" as opposed to clicking on "Close" button... These two way may or may not do the same thing behind the scene. In fact, the radio button change aleeady seems to handle the switchover (4G to 8G, vice versa). Then, again, why have two way of "closing" the window? I'm just thinking out loud....... I dont really remember but I think frameless windows were not possible at the time, were they?
Does the scope need a quieter CPU fan ?
Do you know how to change the CMOS battery in the motherboard? I dont see a CMOS battery in motherboard. I see one in the one of the plugin cards, probably the data-acquistion card. Thank you in advance.
Hey...so what is the name of your gray helper you got there....???
Kennynva T. His name is Pooch. :)
Nice, nice fix :D
Where did u acquire it? How much $$ ?
But can it run Doom?
Another stupid comment instead of soaking up this intelligent guy's knowledge...current state of affairs.
Try and be prepubescent cute as opposed to wits.
@@iamthenra.4842 It was 3 years ago...
I bought one of these myself.
Though, the problem mine had were a dead hard drive, and a broken screen. (Probably CCFL back light driver being dead, but using an external screen is a simple fix.)
But I need to find a source for the software for it.
witch one?
@@LisasexgeilesLuder Good question. I don't really know. But to what I have gathered it is the same as shown in the video.
@@todayonthebench I am currently looking for a scope too an i am thingking about a 54815A (the cheapest one) if i buy i would use a ssd and dump the drive
@@todayonthebench but thoese scopes are expensive (540€ in germany) and for 500 ill get a new 100mhz rigol without old electronics with risk of dying
its 500MHz 1GS/channel
👍
do you have the setup files?
👍👍
earning that phd degree :D
Good Stuff. .:)
Fan bearings sound like they’re going…
👍😁