check the attenuators. another big issue with these is the attenuator relays getting sticky. much harder to repair than usual attenuators in benchtop analyzers. very tricky to open the relays...
Thank you for that tip! I did not explicitly test the attenuators yet in normal operation. I believe they do click around during the application self test and on power up, not sure if the analyzer does an alignment on boot.
Very good follow up. I'm glad the instrument worked. I like when talented individuals like yourself are humble enough to get the help of other experts -talented in ways different than their own. Positive outcome!
I'm so happy that it worked ! Congratulations. Btw i really appreciate and respect that high level of knowledge you got (your lab is a heaven). Greatings from Algeria 🇩🇿
OH, and BTW... thank you for practicing ESD safety!! I appreciate it!! Also, I have used Gorilla Waterproof Caulk Seal for bonding, and it works well. It's a semi-hard texture when it cures, not the soft-squishy texture.
I don't see that ESD awareness at Northridge. My Lab was scrupulous about it when we were developing cellphone WiFi for the first time...what we didn't need was extraneous surprise failures along the way!
Sometimes, those types of pins can stuck, staying in contact for a long time. You can put some oil and remove excess oil, next time it will be easier to remove and it will not stress the board.
If you had a good board, why use parts from the good board to fix the bad board, why not just swap boards and be done with it? Maybe I missed something.
I'm glad you made it work but boy, is that a bad connection design! Like in bad-bad and bad-bad-bad!!! It's that easy to rip the connector off if you don't know what's under the board and you lift it at an angle.
Great video , I too saw the repair that Alex did..... Wow when you said let's go down to a LOW frequency at 100 to 200 megs , I was thinking , wow that is low for Kevin he's used to working at the microwave level , I work on stuff at 300 KhZ , now that's low , almost down in the AM radio broadcast band... Take care Mon Ami..
Thank you! Yes, the LO1 unlock error is quite common on these units. The culprit is cold solder joints on one of the 3 VCOs used in the spectrum analyzer portion. The Signal Path actually has a great video where he covers a repair of this condition: ru-vid.com/video/%D0%B2%D0%B8%D0%B4%D0%B5%D0%BE-1_M-Wccn2w8.htmlfeature=shared I've repaired a bunch of 2721Bs with this fault too. If you're not comfortable doing it yourself, feel free to reach out through my business contact in the description.
Pretty much. The bootable compact flash can be removed without damage by first unscrewing the motherboard. They don't bother and just break the socket ripping it out. They also rip all the SRAM off on the back of the mobo. Ironically, there is also more SRAM on the front but that never gets touched, again because nobody bothers to remove the motherboard.
Awesome follow up. One of the best I've seen for sure. I didn't realize what this unit was until I watched the follow up. wow, is all I can say. Have a great day.
holy crap i didnt get a real appreciation for how small those components/traces are from the northridge video because he never quite showed them in a comparative light but this puts it in a new perspective how tiny that is and how hard that work must have been
Your RTV number sounds familiar, but I don't have any recollection about its post cure strength. I hope the best! I probably would have (made the mistake?) of trying to apply epoxy to the ends, or the RTV all the length. Great education...
*Following Anritsu's own example of securing caps, I would have secured connector with an epoxy having similar rigid adhesive properties. I hope that no one has to remove that front panel again. I say that because Dowsil 737's mechanical strength is only 175 psi and peel strength is only 20 ppi. A durometer of 33 Shore A scale informs one of its flexibility. You want rigidity similar to that of the PWB here. Just my two cents. Cheers!*
...and just for the sake of equally saying, when the military upgrades equipment, in this case, electronic equipment, the Pentagon contracts a government approved civilian scrapper to dispose of the equipment per instructions. The civilian scrapper actually pays the government for the scrap, typically by the pound. So, it's not like there is a bunch of military personnel taking this stuff apart and 'effn it up. It's a civilian contractor, parting stuff out, saving precious metals, and reselling to the market. No offense to anyone, but scrapping is not a highly skilled job.
I dont know the first thing about electronics but I do know a bit about adhesives and am I wrong in assuming that most silicones don't actually adhere well to pretty much anything else that glass, silicone and other things will silica in it...? Epoxies and polyurethanes however are famous for bonding well to most things. If there's a high end epoxy of PU that is known not to mess with your traces and not conduct, I would have used that, ground out a small undercut on the connector and scuffed whereever I could to get even more mechanical grip for the adhesive.
The basic function of a spectrum analyzer is to detect and measure the strength of various signals. It is used mainly for wireless signal analysis, since modern spectrum analyzers can easily detect higher frequency signals used in technologies like mobile broadband (3/4/5G), WiFi, Bluetooth, just to name a few common ones. Of course, those are only a few of the thousands of possible uses. Anywhere you have an AC signal, a spectrum analyzer is one of the basic instruments for analyzing said signal.
great work ! We have at job one MS2721B also; and we need to change de LCD display. Do you know where can we get one and also the N type RF connector??
I'm one of those who been curious to see if it will work again, and it's a really good idea to add that reinforcement before (if it ever need to be unplugged again). Really happy to see it back to life and working. I can imagine a huge smile on Alex's face saying once again; "We did an amazing job !" 🙂👍
Caught this off of Northridge channel. Can confirm your statement. It was a great TMDE item for vswr, freq, and phase measurements. Used serveral over my military career spanning various equipment items.
YOU HAVE NOT YET LEARNED THE DIFFERENCE BETWEEN you're - you are - Your I am curious why is elementary so difficult for you ? Do you have a genetic Learning disability ? RECOMMENDATION: Learn to pay attention to detail and undertake an extensive reading program to educate yourself. Also - learn that Acronyms are to be written in ALL CAPS - because they are ACRONYMS and not words Explain the difference between the following pairs: ARMY - Army NAVY - Navy AIRFORCE - Air Force TESLA - Tesla APPLE - Apple United States of America - UNITED STATES OF AMERICA You can do it. Good luck and Good Bye Also learn the difference between By But Bye Bi Be sure to include the essay in your reply -- so your progress can be examined. When you reply too early I will know that you did not write an essay and your reply will be ignored for being a scholastic failure, -- Third-Party replies IGNORED COMMENT REFERENCE: @HavingFunRepairs.2023020870700
I am not experienced in pad strip restoral, and this was not a good first project to practice on. I'd rather send it to a pro in this method than risk damaging this board myself. Plus, I enjoy Alex's content and wanted to show some support.
The MS2721B is a spectrum analyzer. Think of it as a very wideband (large frequency tuning range) radio reciever. It can detect and measure the strength of signals which have a frequency between 9 KHz to 7.1 GHz. Most WiFi signals are around 2.4 GHz and 5 GHz, so you could detect WiFi and other signals around it. If you suspected that a rogue signal was interfering with your WiFi, you could use this instrument with an appropriate antenna to detect the interference.
Saying that capacitors are on the way and it's hard to repair because of that is real short sight. As 6 easy de solderings later they can be removed to work on 24 broken pads and then put back on after work. The thing that they don't need a fix is not reason enough not to take them off the board for a sec.
It is not just a matter of soldering. 24 ripped pads on a scarce board is not a good first project to learn pad strip restoral. I'd prefer to send it to Alex who has done this many times. I'm also busy with customer units, and this was my own side project.
@@neonkev7866 That pad repair is beyond my skill & dexterity level. Alex did an excellent job. I would consider using Alex for similar work since I am in West LA.
@@Chris_Grossman I once resided in West LACA 20 minutes East of Santa Monica within spitting distance of SONY Studios Was invited there to see how Video post-production was done - At that time it was a movie starring Farrah Fawcett- Majors (Now Deceased) Movie Title : Extremities
