TSP

In this episode Shahriar explores the cause of failure of an Agilent E4405B ESA 13.5GHz spectrum analyzer. In a previous episode, an E4407B version of the ESA was repaired and upgraded which is helpful in debugging and analyzing this instrument. The instrument displays LO Unlock which is a familiar problem. After an overview of the system block diagram, the LO signal path is traced and analyzed for problems.
After some investigation, the problem appears to be identical to the E4407B model repaired before! The Hittite (Analog Devices) divide-by-4 static divider unit has failed and does not divide correctly at high frequencies. The component is replaced which restores the instrument’s functionality.
The LCD screen of the unit is also very dim. The CCFL tube and the inverter are replaced with an LED back light instead. The unit then produces a bright and vibrant graphs and text. The performance of the instrument is verified with a Keysight MXG signal generator.
The Signal Path
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[@DrTune]

That bit at 3:09 when the camera pans across a replica of the Great Wall Of China constructed from test equipment.

[@PaulHigginbothamSr]

HBib:: when you put out a really knowledgeable video that is clear thoughtful and complete people think they have your diagnostic ability to find the problem easily, not remembering how many false trails you followed in a short period of time. I think a lot of these analyzers will be available again ten years from now when they are given up for recovery, not knowing a lot of units are unrepairable because of unobtainium components.

[@ernestb.2377]

I like to see that you put some towels under the SA front as you work on it 👍 Not all of the people or video makers treat the equipment right.

[@freddiemortos8519]

I don't understand what you're talking about but I still enjoy watching it. :)

[@jjoonathan7178]

Looks like electrolytic caps might have competition for the title of "part that always breaks"!

[@larkincrutcher3424]

Great repair job!!! I was surprised that you had obtained a schematic of the equipment. What is your source for schematics of Agilent/Keysight equipment? They make a huge difference in repair task.

[@CNe7532294]

I've been tracking these scopes for a while now. They are ridicuously priced regardless of your first video. I have no idea why. As you said, I've seen them muddy. Some really look like someone just decided to dump them in a river and leave it there. For something that corrodes they still sell for $1000 - 1500. I think it has to do with grabbing out the parts for resale since its a more recent SA. Same goes for the "EC" type for the 8560 series spectrum analyzers. I can get an E-series for way cheaper than an EC. I was "lucky" to get a 8563EC 006/007/008 for an half of an equivalent 8563E's price but the catch is broken aka "attenuated to 30dBm" RYTHM with broken A14 and A15 boards. The boards are easy but that RYTHM is tough.

[@nataliartemenko8722]

Excellent !!! Very BIG thanks !!!

[@PileOfEmptyTapes]

I would concur with others who've said the diffusor is probably just yellowed. Not sure how exactly those are built, but if acrylic is involved, that will yellow under UV exposure, and I assume CCFLs are not too different from other fluorescent lamps which generally produce plenty of UV (along with some heat). Incidentally, there are some dealers for CCFLs, like CCFL Warehouse. No idea how good their stuff is though. Looked into them a while back when I considered revamping an old 19" LG-Philips IPS panel with tons of hours of graphic design on it (but it also had a massive amount of image sticking like I've never seen before, indicating it used to run very hot, possibly at high brightness under poor ventilation, so heaven knows what shape the rest of the monitor is in). Maybe I'll come across a super high end Eizo one of those days, or I'll just tackle the very worn L795 that's floating around here. It would be interesting to investigate why these divider chips are failing. Might be the silicon itself, especially if they are running hot, but in the past the reason often turned out to be absorbed moisture. I'd be tempted to try heatgunning the chip and see what happens.

[@mikesradiorepair]

I have found KZbin is really good at one thing, driving up ebay prices. I do a video on a radio and the prices go through the roof. LOL, we should get kick backs.

[@pu1ypj]

Before he did the initial repair, we could find Spectrum Analyzers like this for less than a thousand :(

[@QLTD]

it sucks

[@Dyaxxis]

Like anything on eBay, some of the postings are simply a ripoff. I just ignore those "parts only" items that are totally beyond economic repair yet are outrageously priced.

[@anullhandle]

MikesRadioRepair . To monetize it just give a heads up to your patreon members before your video goes public. :)

[@PapasDino]

Did you ever find a source for the front panel probe power connector you were trying to find a couple of years ago? Your borrowing of power for the DC converter reminded me as I'm still looking for the proper connector for my Rigol DSA1030A-TG to power a home-brew high-Z probe for the SA. Thanks for sharing another great repair!

[@JonathanTorney]

I have at least 3 of these in my junk pile at work with this exact issue.

[@overtone_audio]

my unit went down. display lights up blank. opened the front panel, checked the ribbon cable and the flat cable to the display. no go. any advice would be greatly appreciated. it was gifted to me by my mentor, great sentimental value...

[@yenaurapourtoulmonde]

Excellent, again! Thanks

[@ManofCulture]

This is beyond my scope of electronic understanding :3

[@audiotecnologia4084]

excellent repair and the backlight was great !!

[@pufero1]

well the no dimming black light was abit stupid when any recovered laptop led blacklight got brightness circuit and they used for use dim and PWM plus the yellow polaricers are not right just sounds like the plastic aged and turned yellow.

[@audiotecnologia4084]

I've already picked up cases where the polarizer was darkened, this caused a yellowish tint

[@tonybell1597]

Riveting watch, thanks. Thouroughly enjoy your simple, easy to understand approach, even though I dont fully understand the tech!

[@saeedsobhani1981]

You went all the way to fix the equipment, just make the backlight dimmable, so the user can adjust the backlight

[@teemoinvietnam1356]

Put the link to the other vid into the description pls

[@oOMonkeyMagicOo]

kzbin.info/www/bejne/nZOUgoCAqdyoo7M

[@hannonm]

Can We have a Hand Held device repair??? Those are so much simpler...and more direct.

[@NatureAndTech]

What software are you using for showing the schematics?

[@vincei4252]

Is it a problem with the Hitite parts or the design? Anecdotally, I gotta admit I've seen you replace Hitite dividers more than twice in differing instruments.

[@rlmillr]

I have an 4403b with this same problem. If I reduce the end freg to ~1.5ghz the LO stays locked above that, same issue. I think I will try the same chip. I think you call it out on your other video. I also have a 4402b that has display noise and no external video. The problem is the display chip on the processor card as it goes directly to the external display. Swapping the CPU card confirmed this. I have not been able to find a replacement chip. Any ideas?

[@omskariyazmaraikayer913]

where can u source the LCD of these family of instruments?

[@BijuKumar-kj7qr]

Thank you ....

[@NuggetNapper]

At around 18:46, shouldn't you have terminated the LO output?

[@michaelschaffter859]

I have an E4402B and when it tries to calibrate the RF or I turn on the RF tracking generator it makes like a hissing sound. What could that be? Or is that normal?

[@cadsonmikael9119]

I have the same. Searched around. It is apparently the chirping sound från the auto alignment. Absolutely normal. Freaked me out as well.

[@zvpunry1971]

The room with your computer has too much echo. Get some things to absorb the sound like a carpet, curtains, houseplants and a sofa for the cat. ;)

[@Krawacik3d]

Or more cats

[@zvpunry1971]

How many cats are needed to get a room quiet? At what amount of cats would the purring and meowing be louder then Shahriar? ;)

[@gbowne1]

I'd go for a dog named Cat

[@gacherumburu9958]

👍👍

[@friedmule5403]

I am wondering on how do people get money for there labs? You see a lab and in the corner or on the shelf, there is a stack of gear, each costing between 2,000 and 10,000$ each, maybe 1,000 to 4,000$ used. How do they do that?

[@atq]

They work ...

[@djreactive]

i rely on ignorance and auctions to buy lab equipment, 95% of people don't know what the equipment is for

[@friedmule5403]

@@djreactive Thanks for replying, that is a great advice! :-) What make the prices so huge for me is that i.e. $400 is what covers all my shopping for an entire month and then is there about nothing left, so alone $1000 will take me maybe 6 months off saving, so $10,000 is totally insane and $30,000 is what a really great new car is costing, including taxes and everything.

[@sefarkas0]

Where do you get the LED strips? Thanks

[@mrkishan4905]

Please display problem

[@ElsuhdElectronics]

I like your video very nice and I like to ask you if you have any test equipment that you don't nead like oscilloscope electronic load please let me know and I will pay the shipping cost because my lab is empty 😁.

[@Multifuchs]

- Keysight -

[@SidneyCritic]

Shame about the colour. It's like that plastic diffuser turned yellow from heat and age.

[@RupertHandford]

Any chance you can lend me a SA for a project I am working on? Can't afford to buy one as on benefits 🤕