TSP

[@TheRadioShop]

I think it is great that you take the time to show the troubleshooting on this type of repair. Most of the time when a instrument like this comes across the bench the first thing techs do is change out all the caps. In this case it would have solved the problem, but no one would learn anything. I do hope you can reach 100k subs. Like you said we have a small audience on these type of videos. Just over two years I and I am about to hit 5k. Thanks for all your work.

[@rasz]

no, people that change all the caps already learned that its the caps that fail first.

[@yasirnoori4848]

Shahriar, don't let the number of subscribers put you down, the quality focused contents you're providing make a greater difference to the community, so please keep going forward with this type of videos.

[@DetrimentalScience]

The logo on the bottom side, bottom left of the silk screen almost looks like a flux capacitor. Never doubt that your videos aren't helpful for people that like it! It is hard to find this level of quality ANYWHERE else. Even though I don't have even 1% of your knowledge, I still learn a lot about problem solving workflow for more simple devices.

[@winstonsmith478]

A $12,000 frequency counter for $650 and a few hours time to fix it. That's a real win.

[@JohnGotts]

It's neat to be able to look at test equipment that mere mortals like us never get to see. 46 gigs goes way beyond anything the hobbiest in 2017 would ever want, but as the march up in frequency continues perhaps some day applications in that frequency range will become more common. And great work on the repair. Just a five cent cap and a fan in the end.

[@mikeselectricstuff]

Bad caps on the primary side are such a common fault on PSUs I usually replace them by default without even testing.

[@Thesignalpath]

Yes, you are right of course. I was just all too eager to get to the frequency counter itself! :)

[@EyalSoha]

Hey, spoilers! :-)

[@TehMG]

Yep, most of the SMPS I've repaired either had bad caps feeding the driver IC or bad caps on the secondary side. Extremely common fault, and by my observations often the result of poor component placement. Many times when I find a bad cap in the supply circuit of the driver/PWM IC, the cap is located very close to a hot part such as a heatsink, power resistor, NTC, etc, which leads to the eventual failure of the capacitor. I've found this design defect in many power supplies even from reputable manufacturers. No matter how good quality electrolytic capacitors are, they all eventually succumb to high heat. Good design practice is to keep all electrolytics well spaced from heat dissipating components.

[@JetNmyFuture]

What a unique piece of gear - so few people will ever need such a counter. Totally disabled by a single part. I had a failure on a high-end LeCroy DA1855A differential amplifier but the failure caused the PSU to pulse high voltage into the circuit, destroying the unit beyond repair. Look forward to seeing this used in some future video.

[@jonka1]

I think the number of subscribers is a reflection of the world we live in rather than your excellent content. Thank you for wanting to do this.

[@k1mgy]

Congratulations on this video. It exemplifies what happens when knowledge, experience, and a careful approach is combined. These are the kind of videos I find extremely helpful.

[@AmRadPodcast]

Congrats on the fix. Nice addition to the bench!

[@stefanosmakris5641]

Amazing. Yesterday I finished repairing a SMPS with the exact same IC that had failed for the exact same reason! I wish that you would have posted this video a week ago and save me some time of troubleshooting! :-)

[@nplanel]

Good work, so the hall effect sensor that you found come from the fan

[@Narwaro]

“Please be very careful ... I’ll set it to something non-lethal” Me, a Physicist who has already touched 240VAC multiple times and whose collegues measure exposed 2kV wires with the justification “I was being careful”: That’s cute :D

[@funkyironman69]

14:40 Although, if it did have power factor correction it'd boost the rectified voltage to ~400V DC. So it could be unsafe even though only 30V AC is supplied.

[@patriotik]

Thank you for making another wonderful video. Always great to see your new releases popping up.

[@TecKonstantin]

you probably already know but the Weinschel Planar Crown is supposed to have the ground inside, without you would get tremendous reflections. Normally they are pressed i and should not fall out. And yes they are rare but they are quite good because the impedance and parasitic of the spring contacts are really low. It also has some advantages because it will lock in rotations an so prohibits rubbing of the surfaces unlike SMA, APC7 and such. And you do not need torque wrench. They have a whole ecosystem around that form changing damaged connectors quick and easy, an also to have a common connection to adapt to any other standard. Maybe someone at Agilent design team had a representative from Weinschel convince them ;)

[@ronniewilliams3420]

As communication tech I suspect the caps, resistors, check supply next, etc., just common sense stuff, I first learned in the US Navy. Yeah Go Navy. I always enjoy your videos ... :)

[@gbclab]

And what an excellent scope you have too! I've got today one HP 53150A with a primary fuse broken, now it is perfectly working, olny I have to check the fan operation...

[@grahambernard3932]

Quality commentary. I got a wee bit lost around the logic flow. That's not you it's me and not having an advanced understanding of logic electronics. However, with your intuitive tuition on these aspects I'm sure I shall keep learning from you. Also, I enjoy your exclamations of success and the "beauty" statements and your "wonderment". Oh yes, I subscribed.

[@PlasmaHH]

This is really the ideal thing to setup a lab: produce content, use the money generated by that content to buy stuff to repair, produce even more and better content, repeat until the lab is the best in the world ;) I wish I had time to do such a channel ;)

[@DoRC]

30:00 The fact that in the beginning you said you couldn't be bothered to recap the board made me laugh... :)

[@Thesignalpath]

Yeah... Oh the irony!

[@alexreeve]

Haha, yeah i was like "oh-oh" when you said you wont recap... i sometimes say the same to myself... and end up finding a bad cap after alot of troubleshooting.. darn! ;)

[@joes5669]

Oh man. Keysight should be paying you big bucks. Every time I watch one of your videos I end up on their website!

[@CNe7532294]

Reminds me of a repair I did 2 months back for an old HP lead acid charger/inverter. Powered on but only with fresh battery. Charger wasnt working. Traced it to the unit's SMPS. Eventually traced it to the PWM chip Siemens TDA 4605 made by West Germany (unit is old). I also thought the BUZ90A Mosfet to be broken but it works. Turns out its almost the exact same issue here.

[@Darieee]

This was amazing ! Not to mention highly informational; thanks a lot !

[@AlexeiPolkhanov]

Wow this is a great repair video because failure was not so obvious. Just replacing all electrolytic capacitors without the analysis would have killed the entire plot. I have heard your short comment about the videos at the end. Please keep the videos long and detailed. I don't know about others but I often watch every minute of entire video with interesting DETAILED analysis like this and sometimes I do it twice. Short 10-20 min videos are just too boring and missing all the juicy details.

[@DoRC]

Too easy. I keep waiting for a doozy of a repair but you are super lucky!

[@AngDavies]

Always a nice feeling when you happen to by luck guess one of the faults immediately :). (The pwm controller) just a visual inspection made me notice that little tiny resistor next to the chip was discoloured to the point that the bands where disappearing and I kinda drew air through my teeth and thought that ic is not going to have liked that is it :/ Really rather close proximity, but I guess it probably wasn't a problem when the fan was working. The second fault did seem very "capacitory" (failure under load).

[@zvpunry1971]

Where did the hall-effect sensor come from? Maybe from the fan? Does that sensor still work? So many open questions. ;) I wouldn't install expensive frequency references in all these devices. I would prefer a good gps disciplined OCXO and a distribution system to get the 10MHz (and 1PPS) where needed. But even this would be expensive, but there are people who have built such setups with stuff like video distribution amplifiers and rubidium references from ebay.

[@WillArtie]

Thanks again SS! Great video as always.

[@ufohunter3688]

Excellent video as usual. Thanks for sharing it. A side note @21:00: I would use a ~1K Ohm resistor between pin 12 and pin11 and apply + power to pin 11 only. This case, you are protecting the internal Zener diode (12mA Max @12V which is enough to run the chip, a 1/4 watt resistor should do) from over current (in case you apply say, 40V to the input "40v/1K= 40mA" will pass through the internal Zener diode). A low ohm resistor, will also act as a noise suppressor for the power supply. An additional ferrite bead in the path of Vcc ot Vc with do some good too. One thing is not clear to me. Do I need an actual R/C network on pin 7? Or can I apply my own buffered DAC analog voltage, or even an external clock instead? looking forward to your next video.

[@thekaduu]

Perfect! Thank you as always.

[@Andrewausfa]

Excellent video. Thanks!

[@jackm_]

between you and the other easy fixes videos and topics, i just HAD TO byte the bullet ;) now i have a working four(three*) channel 500 MHz lecroy that i got for peanuts thumbs up :) *haven't had the time to troubleshoot and eventually repair the fourth channel

[@octavmandru9219]

great explanation on the PS. Thanks! Maybe I can fix now mine

[@colinweiss5175]

Very nice video, thank you! I have noticed that the Counter has an input for an external 10 MHz Reference, as probably a lot other pieces of your testgear have. Even if all your pieces of test-gear have highly-accurate internal 10MHz references, would there still not be some amount of drift between them? Would it not make sense to set up a Lab-Standard 10 MHz Reference and fan that out to all the different pieces of test-gear? I'd be interested in hearing your thoughts. Cheers!

[@PlasmaHH]

Regarding the rubidium, would it not make more sense to get a really good one and distribute it throughout the lab into every unit that accepts external references instead of putting it into single units?

[@jfrede1976]

I think a GPS disciplined oscillator for the lab would be appropriate.

[@HeyBirt]

I get a big kick out of your cat getting involved with your work. My cat likes to run off with bits of wire and get right in the middle of things. They sure make the workbench an interesting place.

[@wattmeter]

most excellent. thank you!

[@kieranj67]

Thanks, nice repair job

[@gbclab]

As far as you know, are these stable measuring sine signals of low frequency like 1 kHz, 10 kHz, 100 kHz? Mine is very stable with 10 MHz but very instable with a 1 kHz sine wave signal, only stable with square wave signals.....

[@KF7JO]

$20 for a 46 GHz connector!?! What a steal!

[@douro20]

They tend to go cheaply because this interface is rarely used. It's a shame that it is due to the robust nature of the interface, which allows cables to be switched often without needing a torque wrench and minimises damage to expensive connectors.

[@JimMorrison44]

Hi from Poland! Very interesting video, impressive, well-done. Can somebody tell me how much such Agilent, like here, working condition goes as for March 2023? Thank you.

[@senohpi]

I dont recognize the white RF testcables, what brand/model are they?

[@EvanZalys]

Should that SMPS not be run with a load? I know some will burn up without a load... plenty just won't regulate.

[@ironman7261]

love the repair videos I think its foolish that high end counters like that would not come with oven controlled crystals as standard

[@JGunlimited]

Is it possible to test whether a capacitor is good or bad without desoldering?

[@freetoc1]

Excellent. thank you!

[@ivanblogs]

I know it's drudgery, but consistent info in descriptions on your videos would be very handy. When you mentioned Patreon, I went to find and click your Patreon link in the description (I don't see any). You can guess what: (No description + No link) * No patience = ?

[@DaveMcAnulty]

Isn't the LoZ only for AC measurements? It don't load the DC line when testing with it, does it? Jealous 87V user here :)

[@heathwellsNZ]

Immensely interesting! Thanks!

[@bsalai]

This is a little off topic, but where did you find the cylindrical supports for your shelves. My cinder blocks are sturdy but they take up a lot of space. Thank you for all the work, I have learned a lot. Brad

[@garci66]

waaay too late, but those are from IKEA. I was using the same for a monitor stand at my office. They are nice since they are adjustable. That particular model might be discontinued, but the "CAPITA" ones are probably very similar: www.ikea.com/us/en/catalog/products/30263575/#/60263574

[@JustSomeGuy1967]

Have you been involved in Exalt or SIAE? Just wondering...I am a small WISP and over the last few years have built 40 mile hops with these two manufactures and am always intrigued how awesome these microwaves work. Watching your videos has made a lot of these thing more understandable to me...thanks.

[@adithyayuri]

great video ........ thanks ........

[@TiBiAstro]

Aaaand subbed. Love stuff like this.

[@pa3deeghztv302]

nice video also nice counter keep it going....

[@mcintoda9]

Why is the firmware split into even and odd bits on two chips?

[@cmdstraker]

That little fan seems like an odd design choice. Even if it was working at peak efficency, how much could it actually do without an air duct?

[@vaniz2012]

Perfect

[@firedeveloper]

Any info from the IC that fell at the beginning?

[@Thesignalpath]

Likely a Hall effect sensor from the broken fan.

[@rhirsch81]

Ten bucks says the mystery hall effect sensor fell out of the broken fan.....

[@antoineroquentin2297]

Where could i get faulty lab equipment (to repair)?

[@Thesignalpath]

I get pretty much everything from eBay.

[@antoineroquentin2297]

Any particular keyword?

[@PeterWalkerHP16c]

The Bell Labs and Patreon is just a front, the real moneys is repairing gear to a couple of thousand percent markup !! :-)

[@m93sek]

Can I cook my noodles with this? How many watts does it have

[@lordhelmchen100]

650$?? damn that was a great deal :D

[@joopterwijn]

Thank, "Nice content" to use your own words :-)

[@cncdavenz]

Maybe some cat videos would help with your subscribers :-) Again another interesting video. Cheers Dave

[@materialsguy2002]

Two thumbs up! If I could spontaneously generate 1E5 subscribers, I would. That said, you are doing good work.

[@SianaGearz]

Don't be so modest. If EEVBlog can have half a million subscribers, then you can have 100 000. But then, i think w2aew will hit it first, sorry :P

[@gglovato]

Actually this was more a "HP PSU repair" and "partial teardown"(we didn't see inside the cans!). Also, ¿¿¡¡how come these devices do not use RPM-monitored fans?!?!, it's beyond my comprehension that these very expensive, very high end and very high-margin equipment have straight to VCC dumb fans(and it's not the only one, of all the teardowns i've seen in YT not one has RPM control/monitor)

[@Thesignalpath]

I promise to show more of the unit when I upgrade it. :)

[@OC35]

That white powder looks like it came from the battery.

[@Arek_R.]

Duh, 40 min vid about repairing SMPS...

[@jonnysolaris]

avval

[@plemli]

Well-meaned thanks anyway, but the repair of a basic swps isn't that interesting. Spending more time on the instrument itself would have been far more rewarding for your viewers.