#88 - HP E4421B signal generator repair

[@McTroyd]

The line between genius and insanity is measured by success. Well done!

[@xDevscom_EE]

Yay! Loose cables repair, most fun ones.

[@davido.hamilton3254]

Fabulous video...thanx so much! I have the HP ESG-1000A that I just purchased. Circa 1997.

[@andymouse]

What a great result, but quite a gamble ! This is good timing for me as I finished watching all of your vids a day ago, thanks for them, they were entertaining during this lockdown and I have learnt so much about you repair process and much more in general...cheers.

[@binarybox.binarybox]

Well checked out. I enjoyed watching your logical approach. Glad you now have another quality piece of test gear.

[@Homer19521]

It is called: "The laying of the hands". These devices are not inanimate, as portrayed. They just want some TLC, like us inanimate's. Well done. I just fixed my exercise bikes computer the same way. It was the ribbon cable. Cleaned it's connections & reinserted & viola! Now the bike collects dust better than before.

[@paolomonai9511]

Good morning. Very nice acquisition. Congratulations. The fault was probably due to a loose connection made by the guy who reassmbled, in a great hurry, the unit...cheers from Italy.

[@loualbert6051]

Excellent troubleshooting

[@ronniebrown8775]

That was amazing! I should be so lucky! I truly love your methodology for troubleshooting things like this! You are truly a gifted man! Thank you for sharing!

[@_hackwell]

You've been lucky on this one ! I spent hours to fix my E4432... Ususally these generators show an 'unlevel' error caused by a faulty output board. Some bad RF amplifiers if you're lucky. If you're not : bad IQ modulator... Luckily there are good resources on the EEVblog forum

[@HelmutTschemernjak]

You are not crazy, the E4421B is a fine device, thank you for the great video. I own a E4432B and the mechanical attenuator was stuck in the 20dB relay, I fixed it by making it movable again. The o-rings are not perfect but still ok. I got spare o-rings and will add them once it is required. Regards Helmut PS: Why not to add PayPal link to the description, I am happy to sponsor your Lab.

[@DavidSmith-zx7wz]

Absolutely love your repair videos, Thank You.

[@SoddingaboutSi]

Great score! And a great feeling to repair too!

[@etienneguyot9069]

Great acquisition, worth the money and effort made on it. On a system I maintained, I recall having a problem with the soldering of a SMA connector on its semi rigid cable. It induced a power loss, but once this cable was removed and reinstalled, I had to wait several weeks for the issue to come back... Finally found, with luck! Maybe a clue to find an intermittent contact?

[@PapasDino]

Great fix as usual! Thanks for sharing!

[@MrDubje]

You're crazy if you say so yourself, but at least it's in a good way! Nice score and "easy" repair. Easy in quote marks because you need to have similar equipment to diagnose. Thanks for the video!

[@ljubomirculibrk4097]

Bad contact on the pogo contact, oxide layer or just stuck spring, nice

[@TheDefpom]

Awesome acquisition.

[@stephenbell9257]

Check the battery while you have the case is open. This battery is required to hold user data in battery-backed RAM.

[@feedback-loop]

I did. It is fine. Thanks.

[@amirb715]

wonderful video as always. you are not crazy, I was about to buy that unit myself! I could sense the PSU was still in there from the pictures that the seller had posted but in the end I decided not to because I really have no room anymore... about the problem with the ATTN, I am puzzled too. Actually I have a very similar issue with the attenuator in an Anritsu SA. It shows about 4-5dB loss but all pads work perfectly fine however the difference is that I do see that 4-5dB loss on the SA. In your case it seems that the calibration of the unit is taking care of that 5dB loss (so it is putting 5dB more power into the ATTN) but I do wonder what the problem could be.

[@foxhound4218]

That's why sometime we knock on the instrument when it doesn't work....

[@dimmog]

The dent on the bottom panel suggests that maybe unit was dropped during repair of burnt input filter and this led to a loose internal connection in attenuator.

[@video99couk]

I wonder if the output was low or if different attenuator settings would have produced different results. If the fault re-occurs, it would be worth checking that for clues. But let's hope it's not going to re-occur and it was just a cabling problem.

[@alainbibi0047]

Hi, opening an HP electronic equipement is nightmare: tonnes of screws, not like Hameg. Thanks for sharing

[@nikmilosevic1696]

Very nice. Ended up being a crazy good deal I think.

[@TheGmr140]

yeah that is a great unit, half of my crazy radio videos are made with this.

[@jdmccorful]

You're one sharp cookie!

[@deedledum21]

Really enjoy your videos!👍

[@TheDefpom]

Nice unit, I like test gear 🤓

[@ELECTROxigeno76.]

Great vídeo máster, tks, 🤝🤝💯

[@ptronix]

Weird fault & strange that the original owner didn't bother to replace the mains filter, but their loss is your gain

[@sergeaudenaert]

Great job!

[@bertoid]

"scrappers" cut off power cables for the copper. They sometimes do only this, even if there's more copper inside (eg microwave oven), because it's quick.

[@TheDefpom]

Those AC input filters blow, I’ve had two fail on gear I’ve picked up, and they absolutely stink when they go.

[@zaprodk]

This is not old enough to contain those dreaded RIFA capacitors.

[@TheDefpom]

zapro_dk - I’m not talking about RIFA caps, I talking about the IEC input socket, some (like this unit) have built in filtering and they can blow up, like I said it’s happened to me twice.

[@TheDefpom]

zapro_dk - here is a video where I captured an AC input filter blowing up, smoke escapes at around 14 minutes in...#212 Behold the MAGIC SMOKE !! HP 8647A First Look, Blown up and Repaired kzbin.info/www/bejne/mWPHmHxtmdp0bdk

[@VintageProjectDE]

I thought of my Schaffner input filter, as well. It went off in my Gould scope, making a nice plume of acrid smoke and some bonus black goo out of the silicone sleeve. For the HP, I guess it blew up and they somehow couldn't order replacements or didn't feel comfortable tinkering with mains voltage and off it went to the bay. Good for FeedbackLoop and his audience. :)

[@manoelmoura682]

Good afternoon, your video is excellent, I have an agilent N9310 a. I carelessly put rf in the input and it lost power, it only comes out -30 dbm. I'm looking for the service manual, do you know any link to get it or any suggestions

[@paulosawka6702]

Hello my friend, my name is Paulo I'm from Brazil, I always watch your videos that are very good and this one helped me to repair an E4431B generator that I still would like to adjust a deviation in the output power of -0.25 dbm I didn't find a way to do it this calibration, can you help me? Thank you very much

[@fixthetempo7276]

Great work! May I ask you a question? Are u from Russia/ex ussr country?

[@TATEXPRESSINC]

Definitely gonna subscribe to your channel

[@AnonymousRepair]

well done

[@adaslabs281]

My Agilent E4428C ESG cannot boot properly, and showing message on the 2 bottom line : Code loaded, transfering control to aplication. Decompresing firmware At this point, E4428C stuck not activity any more.

[@octavmandru9219]

Well, I have the belief that equipment is able to select their owners, and to behave accordingly 😜

[@bansci]

Nice repair, but two synths? And when did you get the E4406A? Test Equipment Addiction is a real and serious problem, stop before you go full Shahriar@TSP (or xDevs_com if DC is your thing) :-P

[@tenareze32]

I learn a lot from your videos, although I would never attempt to repair professional equipment of such complexity. However, I would be interested to know what package(s) you use for interfacing GPIB in Ubuntu.

[@feedback-loop]

I use linux-gpib. Recently upgraded Ubuntu to 20.04, and installed linux-gpib-4.3.3

[@billspencer8540]

Great.

[@bfx8185]

I really like such errors :D congratulation

[@TKomoski]

I'm still trying to understand why ?

[@douro20]

Does that signal generator have the advanced digital modulation option?

[@feedback-loop]

Are you talking about I/Q? Not this unit. That would be option UN4 or UN8, I think. My 2GHz unit has UN4 installed. You can see extra inputs on the left side of the front panel @10:02

[@douro20]

@@feedback-loop Option UN8 is the I/Q baseband generator. They also recommend adding Option UN9 with it which adds 8MB of memory for storing custom patterns.

[@feedback-loop]

I am a bit confused. You seem to know the option, so why are you asking if this unit has it? No mention on the sticker on the back, no input connectors on the front panel, and no optional boards inside.

[@gorak9000]

Seems like this one was a hangar queen - someone stole all the good parts out of it to fix other units, and put all the busted stuff back into this one.

[@douro20]

My LeCroy 9410 came from Hughes Aircraft in California, where I believe it was used for about a year or so and then put into storage for over a decade. Needless to say when I bought it everything was fully functional, with just a slight software adjustment to correct the ADC gain on one channel needed.

[@electricbase1930]

Спалился😂