#34 - Tektronix TDS 540A oscilloscope repair
Вставка
- Опубліковано 28 гру 2015
- This scope suffered from the classic problem for this line: leaky electrolytic capacitors. All 96 capacitors were replaced, and a few broken PCB traces restored. A backup of Dallas DS1650Y NVRAM was made as well.
Schematics: hakanh.com/dl/kits.htm
Service manual: exodus.poly.edu/~kurt/manuals/...
Discussion: www.eevblog.com/forum/testgear...
Followup video: • #36 - Enabling FFT opt... - Наука та технологія
I really appreciate this video because I have just acquired a TDS784A that fails the acquisition diagnostic. This video has given me the courage to open it up and try to effect diagnosis and repair.
I just picked up the same model with similar self test fail. This video is a trove of good info. Thanks a ton! The link to the schematics is especially helpful!!!
*You are so so good at this stuff, it is unreal*
A very good video on repairing a Tektronix digital ‘scope. I learned a lot from it. My next repair project is a TDS620 and the job will be easier having seen your video.
Thanks!
I really enjoyed this video, thank you for taking the time to detail your thought process and methods for troubleshooting. Your tenacious and determined approach shows real discipline and is inspirational to watch.
Thank you for this work. I most likely will need it with my new scope. Due to the expected failures.
Your tenacity inspires me.
Thoroughly enjoyed the Video and recommended it to my fellow engineer friends! Thanks Lloyd - DigiTek
Marvellous. Just as others have said, I’ve recently got one of these with the usual self test failures and your hard work here in this video will be a big help while i work my way through the problems! Thanks a lot.
Great troubleshooting & repair my friend. Glad you got it going properly again.
Well done sir! I’m hope you have a good memory. I just picked up a TDS 554D of my very own that’s in need of some serious love. If I do half as well as you did, I think I’ll be ok. Thanks videos!!
Very nice job. Thanks for the link to obscure manuals, too, that was nice.
Excellent work; goes to show when persistence pays off. There is nothing more concerning when you see corrosion on the boards and especially the IC'S, not to mention all the bad capacitors that were open. I am surprised the scope even powered up, "congratulations on a job well done"
Bravo, great job, congratulations! Thank you for sharing your wisdom.
Thank you very much for this film. I have a TDS540 with the same self test failures so now I have an idea of what I'm facing
GR8T job. It was touch and go there for a while. A real cliff hanger. Thanks for the video. Cheers!
Wow! good job! that was a great deal of work, glad you stuck with it!
Very informative video. I would have never even considered leaky capacitors as being a potential issue with oscilloscopes, with them being such expensive pieces of equipment. Definitely something I will look out for if I decide to buy a scope for a repair project.
I believe corrosion as a result of leakage only happens with capacitors that use more aggressive water-based electrolytes (common since the mid 80s or so -- these small ones here were meant to replace Tantalum drop capacitors)), since the electrolyte from older caps is pretty much just a mild solvent. Seal construction is another factor. That's why so many devices made from the 80s onwards suffer from leaky caps destroying circuits. Meanwhile you will see devices from the same period of time using different capacitors which are perfectly fine decades later. Blue Philips capacitors tend to dry out, but I've never seen one ruin a board.
Great repair work! Bravo! I just want to say that my Tektronix 422 (1967 transistorized 2-channel 20MHz scope, mine since 1975) has never failed or lost calibration (still within 5%). The caps are miraculous, the whole scope is a miracle. I won't touch anything inside until something fails.
Congrats on a great repair! Peter on the TRXBench channel recently dealt with leaky electrolytics that did considerably more damage than you had and showed it is possible to do this kind of repair. Boy, with well over a hundred caps I think I might have bit the bullet and gotten a tweezer iron! BTW, I got some of those Dallas chips a long time ago from a reputable supplier and they all were bad; I think they actually may have been knock-offs that somehow made it into the system - sourcing them directly from Dallas solved that problem. Look forward to your upcoming videos - Happy New Year!
Years later I admire your detection skills. So many faults and now a board with good fft. Fast Fourier transform for prettier waveform. If I get one of these 540's with the caps in this condition I will expect lots of traces obliterated, and probably some ic's dead.
I love your voice and narration! Great job!
Simply AWSOME. I have a TDS620B with a bad channel 4. I think with what i've seen from your video it can be fixed with some work. I'm glad you fixed this scope. You should consider putting all the TDS scopes that this may apply to in your comments or even the title to get more hits. Thanks for a SUPERB POST. Best Wishes n Blessings Keith. PS Thumbs up and subscribed.
I've just bought faulty TDS 620A with the same self test errors. Already inspected all boards and mine has exactly the same ugly signs of corrosion here and there. I wonder if I'll be able to replicate your work, because from the video it's obvious to me that you are much more experienced and have better gear to to that kind of repairs but I'll give it a try. Anyway very big thanks for the video - it'll be the guidance on my path to rescue the scope! ;)
Repairing down to track and via level. That's dedication. One does not dare to ask how much time and effort actually went into such job to yield perfect completion. ;) My natural response would probably have been to push me dirty boot into the corroded old thing and order me slave to do the job befitting a king.
Interesting video. I just obtained the a TDS540 with the same three failures. I hope I will succeed as well.
Huh, what a work you did with high knowhow! Result: workin scope. Thanks a lot.
Such a neat idea ...taping the backup to the top!
It turned out that those labels don't hold very well especially if bent over the edges. Straight labels stick better. Perhaps some other tape should be used
Excellent debug Sir..
Wow, I have used thousands of these capacitors since the 90s. But I stuck to Panasonic, Sanyo and other well known brands. Until now not one has failed. In fact this video is the first time I see one of them failing. Very interesting.
I really enjoy the video, as always.~
Excellent video! Exactly like should to be. Enjoy the scope. Thx
well .. i am speechless ....... genius work !!
Great job! Отличная работа!
Amazing work!
Again a nice repair! Thanks!
I love videos like this where the technician speaks his thoughts as he's troubleshooting. What I'm wondering is - how can there be so many bad capacitors and bad circuit board runs in what was once an expensive oscilloscope? I'm looking into buying a TDS 360 and you've taken a lot of the mystery out of what's inside the enclosure. I was wondering if I would be able to repair one if I got a defective unit. Thanks for taking the time to make the video.
Thx a lot.. I'm at the start of this, i replaced about 35 caps on the acq board, just tried it out and still no dice. :-) No acquisition or viewable signal at all :-) I see i really have to replace all of them and probably more is wrong. But thank you for your link to the schematics, really great!
very good work !!! i really enjoy your video
Good work. Thanks for the video.
Nice video, like & subscribe! I have TDS540 with same problem. Self-test sometime is OK, but oscillogram is poor. Today i buy all cap-s and on this weekend i try to replace all of them.
I changed all of capacitors, but selftest still error attn/asq interface & cannel 1 dc balance is wrong. I found bad ic U1401-C one output of 4 OA on pin 8 measured +3.8V and dc balance gone wrong. I replace TL074C and oscilloscope passed selftest, channel 1 still working correctly. Thank's too much for links to schematic & service manual.
You are extremely good!
man it sounds really nice to have a local electronics store. The closest thing I have is a crappy radio shack.
Gotta feel good to get this one working.
I just finished watching your video. What a great job you did. Have you been repairing stuff like this for a living?
Thanks again for sharing such a great video
Thanks. No, not for living. It is a hobby.
Great video. Enjoyed very much watching/listening while you troubleshoted. Thanks for sharing.
(Also enjoyable to hear various english 'world'-dialects, and I guessing you are east-country, russian or something. Its beautiful that there are so many variations around :-) ..have nice week to you, fam and the surroundings. br, Rolf/norway)
He is originally from Russia but lives in California.
Would you give part number for the caps that you replaced thanks
Hey! I think you should do one of those conversions to the nocolor system. I’ve heard it’s super cheap and doesn’t even need any of those LCD kits as the CRT is color capable
Nice Job Sir.
another great video. thanks
Very nicely done! Excellent job. I wish i had found your channel sooner. With regard to cleaning the corruded boards, how do you rinse and dry it after scrubbing with Simple Green? Do you recommend Acetone for cleaning PCB board with or without SMD components? Thanks
I wouldn't use acetone. I rinse with distilled water (or from reverse osmosis filter) or isopropyl alcohol, blow compressed air under the chips and such, and dry with a hair dryer.
Hi. How is the capacitors value?. Please! Thank you very much
Hi Feedbackloop, I have a Leader LBO522 Dual Trace scope and I accidentally shorted ch1 to mains ground and I heard a loud bang and the probe got damage. However, When I try to use the scope again with new probes, both Ch1 & 2 are giving me some funny readings. Can you point me in the direction or which board may be faulty so I can begin trouble shooting. Thanks.
Thanks for the excellent video. I have 3 Tek scopes with the Dallas chips (one of them it's a digital, colour one, very similar to this one in the video), and I need more, in depth info about how to make the backup (the app you used, etc.), because I want to modify the battery with a new one, which will last longer. But previously I need to do the backup...just in case!. Do you know this procedure in depth?. I think so, because you have made it here. TIA for you help.
Hi I have a TDS420A, is it possible to add the MAT for the FFT?
Well Done!!!
hi..I'm trying to do a copy of a ds1645Y from a tds520.
What programmer do you think I should use?
I think I can also replace it with ds1245y? what do you think?
22:38 "Check this out! It passed the self test!", Congratulations on another job well done! I know you do this as a hobby, however, I wonder, how much time did you put into this repair? Thank you sir. Ya da man!
I like your DIY hot tweezers.
Again nice video
I have the TDS640A Tektronix , he work fine , but it is dangerous X-ray of the Tube when i use this product a long time ? Thanks for this good video !
TNX for the great video !
Have you ever repaired a TDS820 (6GHz 2 channel)?I am currently working on one that had similar faults to your 540.Same cause of problems being leaky caps. All caps replaced but there was no trace and self test failed with Acquisition and sampler1 and sampler 2 faults. I cannot find a schematic.So far I have cleared the sampler1 fault and got it to start triggering which restored both traces and now the setup tests work which did nothing previously. Ch2 has a large DC offset which I think is responsible for the sampler 2 self test fail but the scope will only trigger on the internal clock. External, CH1 and Ch2 triggering do not work at all.
+Jerry Walker
No, never seen one. I suggest searching the www.eevblog.com/forum/, and, perhaps, opening a new topic. Describe your problem, attach photos and such. There is a good chance to get suggestions.
Did the same with my 540. It still complains on acq board on startup, but the rest is fully functional. Still can not figure out what means "ctlConfidence diag, 2.50e-9
That time I started to smile :) 22:36 Congratulations!
do you happent to know somme site where you can find the firmware for various instruments? i have the eeprom and ram from my hp6624A power supply and i wanted to make them availeble to everyone...
+ElectronicMarine
I know of this one: www.ko4bb.com/getsimple/index.php?id=manuals
ok, tks i'll send them the files...
I wish I could find a real of those caps for $10 per reel - LOL. I am anxious to get through your video later. I have a TDS540A that fail Acquisition, that I am guessing is the caps. I don't know yet how damaged the board is.
Hello, great explanation!. Question: I have a "Not Working" TDS540B coming, and I want to be prepared for the recap so I want to order them. What size of 10uF 35V and 33uF 10V capacitors did you use?
The label on the reel says 5 x 5.5 mm.
FeedbackLoop hi thanks for your response, I'll order them that size. In hindsight, I had another look at your movie, and I could see the size on one of the reels. :-)
Great video thanks
What do you do if DS1650 (1250) battery fails and you have no backup?
What are the capacitor values or, ref designators for BAD parts? Thanks
Хорошая работа.
Hi, inspiring videos, I just got a TDS 644B, works ok. it has seen some action and is a little dirty and needs some TLC, was wondering if I should tear it down and clean it?
+Craig Hold
I would certainly suggest having a look inside. Chances are it needs recapping too.
Thanks, so you have a blog?
Hi I have a TDS 320 that is completely dead in blank screen and, saw and hear you speaking about capacitors the tds 320 don't have those big electrolitycs caps but, all they are SMD,I think the problem here is the battery,just don' know if is possible open that memory chip,is it possible?
+CYBERRD58
It is hard to say anything useful based on your description. I would suggest asking on the EEVBlog forum - see the link in the description. It is one of the best electronics forums on the net. Carefully describe your symptoms, attach photos, and quite likely you will hear some suggestions from very experienced folks.
Thank you
Great work, well done and clearly explained. What is the make of your ESR meter? Best wishes for 2016
+rupert handford
This is Tonghui TH2822C
www.tonghui.com.cn/en/Product/lcr/lcr_1/2014/1201/354.html
Thanks.
how can i get in touch with you i have a TDS754D with a strange NVam problem FATAL: 250 nv storage too small, more bytes requested than available ...
I have never seen TDS754D. No idea.
Very nice repair. You put a lot of work in this Tek. Question: Why are you so interested in the TDS540A. You have one already. What features do you like most? Or is it only the repair? When the Dallas chip is broken is the TDS540A beyond repair or is there a solution? Great video, will follow your channel. Bye FEY
+FEY
I just happened to find a good deal. These 5xx and 6xx Tektronix scopes present a great opportunity to have an affordable, but quite capable scope in a hobbyist's lab. Of course I will sell one of the scopes. I don't need two.
+FEY
The Dallas chip can be copied from another scope. See my follow up video.
полезные видюхи, спасибо.
Your repair video and the analysis of the failures and their repair is very attractive.
I enjoy watching it.
Maybe I can get help from members in this community for repair of my TDS744A.
After lifetime of the batteris in the NVRAM DS1650 an the timer DS1486 has ended, I desoldered both circuits and replaced them with a socket. Now the information in both ICs is lost and the scope boots up after several attempts but with lost data and SPC information. I have bought some ICs from china, but I have no Information about the programm to be loaded.
Where can I get it or who can help?
I don't think that UA-cam comments is the right place for this sort of stuff. I suggest www.eevblog.com/forum. Also have a look at this site, which is a great source of manuals, firmware and such (try NVRAM from 784C): www.ko4bb.com/getsimple/index.php?id=manuals&dir=Tektronix/Tektronix_-_TDS_784C. Good luck.
Excuse me for useing a wrong path for my problem and many thanks for Your links.
Nothing really wrong with using UA-cam comments, but I believe that they are not effective if you are looking for technical advice. Especially, from the audience, not the author. EEVBlog forum must be much more effective for this.
What is with the X-ray warning?
douro20 probably for the CRT screen would be my guess
I think you should copy also the schematics you do not have the scope for so in the future when you run into these scopes you will have them because lots of things disappear never to reappear. Good job by the way on the 540 sir. Yaay!
Thanks.
I'm surprised at the number of open circuits you found. And not so happy seeing DS1286 and DS1650 parts with embedded Li battery, even though they are warranted to last at least 10 years with no power applied to the IC.
Oh, I see a LIST!!...Thanks
this guy is not an human... I can't believe it.
I saw in Paul Carlson video (Mr. Carlson's Lab) a faster method to get those caps off. You just have to twist them but you leave broken pins on the boards and you have to desolder them afterwords.
There is always more than one way to do something. That one works too, I suppose. It has its own risks of lifting the pads, for instance. My method is not ideal either.
That was a lot of work, is the scope worth it?
I like it. Very good capabilities for the money. A bit bulky and noisy though.
Hi
My name is Marcelo ,and i need your help.I am trying to repair a Hameg 408 oscilloscope ,which have a intensity adjustment issue.I need a profesional to explain me how this circuit work and which is the relation beetwin the analogic part of this and the digital part .I will send you the schematic,if it is necesary and i will give you my e-mail.
Thanck you , and i hope you will give me an answer.
Thumbs up for the Backup-Trick ;-)
dafuq, how easy can it be....
I have a hard time trying to fathom how a reputable company like Tektronix would install so many bad caps as that?? They must have put them in backwards from the factory?? You paid ten times more than that scope was worth!! 73's , Gary Grove Minneapolis, MN
Как же можно так не беречь технику...
Nice but time demanding job! It is the best case scenario when you have an identical equipment to compare to, otherwise...
Excellent work. I have a TDS524A that turns on and off, but will not stay on. I sent you an email. Hope you can hel
Nice job !
And I thought that Tektronix equipment was expensive because they use only top quality parts... Pfff...
They do, but shit happens sometimes.
AlainHubert my tektronix mint condition rm 585a has never been touched and is in perfect calibration .... Fun to use every once in awhile ...Best part I got it for $50
I would say that scope is still quality..... All them bad caps... But it didn't hurt the scope.
My Tektronix 422 (1967 transistorized 2-channel 20MHz scope, mine since 1975) has never failed or lost calibration (still within 5%). The caps are miraculous, the whole scope is a miracle. I won't touch anything inside until something fails. Tek equipment was worth the price always. I don't have experience with modern Tek gear. I'm still using my 422 and 2465.
👍
Whew!
I always thought caps should be esr tested at 100khz not 1? !.
That's persistence for ya.
Makes you wish for a ultrasonic cleaner.
Круто. К стати, тут уже акцента не слышно. Быстро ты освоился.
Акцент, и очень сильный. Я только потому задержался на видео, что с первых слов заметил типичное российское звучание английского.
First 14 minutes... yeah, I could do that. No problem! Shortly afterwards, he's confirming capacitor trace behaviors against some of his spare units. I'm out! ;-)