#138

[@Thesignalpath]

What a strange issue! Nice find.

[@TheDefpom]

Wow, I’ve never seen a mass resistor failure like that, nice repair work as always.

[@xyloeye]

Thank you. Finally, a youtube repair that wasn't bad caps!

[@IanScottJohnston]

An Agilent PSU I repaired had a similar issue, lots of SMD resistors going open circuit. Begs the question, where are Agilent/Keysight getting their stock from?

[@ChipGuy]

In my Agilent 33220A I had a mass failure of all the bigger Kemet T491 type tantalum capacitors. I thought that was a weird coincidence but your 300 Ohm resistors are even weirder. Congrats for saving that one.

[@nikmilosevic1696]

Well that was an interesting problem, bad 300ohm SMDs, great debug and great video.

[@t1d100]

Wow, a weird fault (301R) and an amazing find (the entire batch.) Kudos.

[@Yorumcu63]

Great repair . Your electronics knowledge is amazing

[@laoluu]

And he must have eagle eyes to even spot these little farts!

[@TheRadioShop]

Interesting to see all those bad resistors. Great troubleshooting as always. Thanks for the video

[@transfunktionator]

Great troubleshooting and explanation, very interesting! We have more than 100 of these generators at work and never seen that fault. Usually, the rotary encoder dies first, and the trigger input gets fried because everyone assumes it can handle TTL levels - but it cannot, and it is unprotected...

[@ydonl]

Sherlock! Thanks for producing these vids; it's nice to see you fixing something a little more difficult! I learn a lot watching them, not just the technical issues, but your general approach and persistence. I wonder how all of those resistors could go bad at once, or... if they did. If they failed while sitting there powered off, just through age, I guess they could have gradually accumulated after the first one failed. Pure speculation! Mysterious (at least to me). I would normally expect parts to fail under use, but in that case, after a certain one broke, the instrument would be left powered off and there would be no chance for more to break. Pondering...

[@saarike]

Really interesting failure and very skillfull repair!!! Thank you very much!!!

[@brendanbarbour8568]

Great detective work my friend.

[@vadimbellous8313]

A surprising issue to be sure. Goes to show, no matter how rigorous a manufacturer's quality control is, bad batches inevitably will still slip through. I've had a similar problem working on a Fluke 725 Process Calibrator, where 4 ceramic caps had identical cracks from the bottom up. Lucky for me, they all failed open because if they shorted that board would have been trashed, most likely. Finding out their value (which turned out to be the same for all four) without schematics was a challenge. Can't conclusively blame a bad batch there, but I have suspicions.

[@klassichd10]

Thanks a lot! Well done! Strange issue. a complete lot of SMD resistors aging prematurely.

[@notJW13383]

Another great video. Please keep making them.

[@artursmihelsons415]

Excellent repair video! 👍 Very strange, that lots of resistors failed. Probably, bad lot from factory.

[@video99couk]

Wow, a bad batch of resistors is a rare thing. I've had cases where a particular value of capacitor is bad all over a board, but never resistors.

[@k1mgy]

what would cause all these resistor failures? any theories?

[@pigrew]

I've experienced the bad resistor issue in the reference circuit of an E3631A. I only replaced a single resistor (I forget the value), and the power supply came back to life.

[@DavidSmith-zx7wz]

You are one smart man! Thanks for the repair videos.

[@gordonwedman3179]

Good lord! A bad batch of 300 ohm "precision" resistors renders an expensive piece of kit faulty. Wonder how many others are out there gathering dust.

[@alanvandusen76]

Interesting, must have been all out of the same batch. Good find and repair.

[@nebicicek7404]

Latent defects... Scary stuff. Those resistors must have been working when the unit came out the factory. What could cause all of them to increase resistance like that?

[@TheGmr140]

Nice gear, and repair

[@paolomonai9511]

Good morning. Good catch, Indeed! The positive thing Is that resistors 0603 have a marking code printed on so even if no layout Is available, with a little effort, you can find and test all one by one. Anyway, very interesting fault, I should say and unusual type. Regards from Italy.

[@feedback-loop]

these are 0805 resistors

[@fixthetempo7276]

good alod known 33250 awg... oh , i miss my time in keysight. Good repair!

[@LoomisRex]

why is there a dc bias on the pin12 and pin 13 on the dac clock ?

[@feedback-loop]

en.wikipedia.org/wiki/Emitter-coupled_logic

[@hinz1]

Keysight with a real service manual, pretty rare these days

[@Chris_Grossman]

Excellent repair sleuthing. That had to be a bad batch of resistors since all had the same value. If it is there may likely be a similar issue with other units from the same production run. What is the serial number of that unit?

[@bansci]

Great repair, can't help but wonder what killed the resistors. Would be nice to see them under a microscope to see if there's some kind of cracking/swelling common to the failed ones.

[@andymouse]

Wow indeed, great work....cheers.

[@vincentjudyjaneric]

Wow, good debug, but I am curious the instrument to fail on DOA(Death On Arrival) or a long time usage. If it failed on a long time usage over resistor parts, it will be quite strange.

[@dimmog]

Just repaired e3634a with 2 open precision resistors.

[@mysticman76]

Are you in Dallas area? I have been enjoying your videos very much

[@feedback-loop]

Do you want to buy me a coffee or something? :) No, I am in California.

[@hydrogenger9364]

Can you please provide the full list of the 10 faulty 301 Ohm 0805 resistors ? You mention only a few: R1148, R1141(?), R1152(?) , and have highlighted a few. What were your actual Rxxxx #'s that were replaced from the list that you compiled ? thank you

[@feedback-loop]

I don't have a list now. I suggest to look up by the part number in the service manual. Why do you need my list of 10 faulty ones (out of 50 or so)? What are the chances that you have the same ones failed? Did you even start checking that you have the same problem? There might be million other reasons.

[@hydrogenger9364]

yes, am checking: so far two of these 0805 301 Ohm resistors in my unit are way off value. Very odd. Continuing to search for the issues.

[@TKomoski]

Who would of thought

[@AB-yu2tj]

Hi thank you that's very interesting. I have a question about the flu scope you are using , is the fluke scope always a little bit slow like that?

[@feedback-loop]

Slow? Perhaps you are talking about slow autoranging. You don't have to use it.

[@RyanUptonInnovator]

Great video.

[@alien8r33d]

How odd. Can't be an issue that's just worsened over time so it must have been caused by a single event. Does the power supply show any signs of repair I wonder.

[@TheGmr140]

Nice gear

[@graemedavidson499]

300… Glad there was not a Spartan FPGA in there too! Humour aside, interesting failure mode!

[@SoddingaboutSi]

Looks like a dodgy batch of resistors there. Good repair

[@MerlinMerlinL]

wow

[@otherbasis8505]

Wash the top metal plate ASAP! It's not stainless - just some galvanic nonsense that reacts with skin fats and whatnots really fast.

[@thatemptyspace]

такой русский английский )))))

[@ДмитрийСумароков-з2в]

косит под иностранца

[@jdmccorful]

Good sleuthing! Enjoyed watching, thanks for your time.