Advantest R3767 / R3765 VNA Service Manual - Page 1
Forum section: electronics / general

author: kjk24
author_rank: Regular Contributor
timestamp: March 31, 2020, 07:08:52 am
content: Hello search the service Manual for the Advantest R3767 instruments.Error = "Synthe unlock"Best regardsKai

author: bob91343
author_rank: Super Contributor
timestamp: March 31, 2020, 07:20:57 am
content: I have a slightly different model, with the same problem. Unlock. I have spent far too much time trying to fix this baby.

author: Marco_Mar
author_rank: Contributor
timestamp: April 08, 2020, 06:35:09 am
content: Hi,I ran into the same error in my R3751A.Try to pull out the cards inside and seat them back again.This was the treatment for my R3751A ailment!Hope this help

author: bob91343
author_rank: Super Contributor
timestamp: April 08, 2020, 04:57:54 pm
content: I tried that. In fact I have lost count of how many times I have unplugged and reseated the modules. I think I have it isolated to one module but am at a loss how to proceed.

author: tmbinc
author_rank: Frequent Contributor
timestamp: April 09, 2020, 01:52:30 pm
content: Had a bunch of "weird" issues (resulting in no error messages, but complete noise as measurements - the JTO never locked), eventually it was "as simple" as replacing all capacitors on my R3765AH, especially on the two modules. Have you tried that?I don't have a service manual either (but would love to have one).

author: kjk24
author_rank: Regular Contributor
timestamp: April 12, 2020, 08:33:33 am
content: "The internal reference frequency source is out of the phase-locked loop"investigate some time to draw my infos to find out how the thing works.i ordered rizercards made by myself, hope they arrive soon.pictures here:https://photos.app.goo.gl/3hdL4SXadJ6MLe9u6

author: coromonadalix
author_rank: Super Contributor
timestamp: April 12, 2020, 04:10:29 pm
content: Beautiful pictures in therehttps://photos.app.goo.gl/3hdL4SXadJ6MLe9u6

author: bob91343
author_rank: Super Contributor
timestamp: April 12, 2020, 07:31:09 pm
content: Replace the capacitors in the module? Which ones? There are dozens of them. At my age I may not live long enough to complete such a project.If I had an idea of where in the module to look, I could do some replacing. I made an extension cable so I can work on the module and make measurements but I don't know what to expect where.Incidentally, this is a different model, not a VNA but a Leader signal generator model 3220. It covers up to about a GHz. I would love to get it running. It's not as good as my HP 8657B but does a good job when it works.

author: imett
author_rank: Contributor
timestamp: May 01, 2020, 04:47:44 pm
content: If anyone need it i've the maintenance manualbut for the calibration after the repair the procedure require a special floppy disk, i don' t have the name of this floppy, for example in the calibration of the output power the procedure talk like that "insert the floppy with file SRC_COR.BAS"anyone have this files?

author: DaJMasta
author_rank: Super Contributor
timestamp: May 01, 2020, 05:51:24 pm
content: Not 100% on the design, but when it says "synthe unlocked" have you been able to correlate signals internally that are obviously out of place?If that block diagram you've made is right, I can imagine three potential causes of such an error message:The base synthesizer output is varying when it shouldn't beThe YIG isn't able to lock to the synthesizerThe fixed 4G oscillator isn't stableIf your 4GHz fixed LO is looking ok (and if the lock is intermittent but works on some ranges, I think this would work), and your primary synthesizer locked to the 10MHz reference is outputting steadily (again, if this is supposed to be fixed and works for some frequencies, I would assume this s alright), then the problem would be with the YIG. This could be the oscillator itself or it could be the amplification out of it (need relatively high output for the next stage mixing, maybe some frequencies are below what's needed) or that something about the driver circuitry isn't able to adjust properly to lock to the synthesizer's reference (the YIG has its own PLL).So I'd check the output of the synthesizer block and then the input and output of the source block to try and figure out what exactly (module level) is up with the synthesizer. Then you can start tracing out the signal on the board and identifying functional blocks. If it is indeed YIG or PLL related, you'd be able to see abnormalities in the drive circuitry, or in the frequency division in the PLL or similar, and if it is power related, narrowing it down to what board will let you monitor the rails for just that module, so if you feel like just replacing caps en-masse, at least you only do it for a rail or two in one module.For understanding troubleshooting methodology in this kind of equipment, I'd also recommend TheSignalPath on youtube, as Shahriar has done some repairs for SAs/VNAs/SGs that use use somewhat similar architectures to generate their RF signals, so you can get a feel for the layout of the boards, the architecture of the unit, or just some common problems these units can run into if you aren't already familiar with it.There are a lot of potential problems, but with a fairly generic error message, I think the priority should be trying to isolate the particular module that is causing the issue - it could potentially be more than one, but I think more often than not a single failure is the thing to bring down the beast unless it's some sort of overload condition.As for the floppy, may be tricky to find but if a physical service manual turns up it's the kind of thing that could be in an appendix or in a pocket of the binder. Just from the name, Source_Correction.Basic may give an outline of what's in there if it needed to be reconstructed... but it would likely be a very tedious task. It could be worth looking in calibration files stored on the drive (or in eeprom?) for values, because I assume that file probably just prompts a cal lab tech to enter levels from a power meter so it makes its own calibration curve (though it could be that the basic code generates the coefficients, and only those are stored for calibration).

author: imett
author_rank: Contributor
timestamp: May 02, 2020, 08:18:59 am
content: HI about the unlock issue the maintenace manual has a procedure. It needed i Will upload that manual. For the floppy i Think the only way to find it is ask to a service centers

author: coromonadalix
author_rank: Super Contributor
timestamp: May 04, 2020, 11:53:34 am
content: Not sure it can help ?Programming manual ...

author: kjk24
author_rank: Regular Contributor
timestamp: May 16, 2020, 07:53:48 am
content: thank you DaJMastafor the detailed explanation to find out where the problem is located, i watched the videos from Shahriar several time to lern and like it.unfortunately i cant refelect how my unit works but i guess its me fault, i miss the point but i dont give upthats for sure.perhaps my cat can help ? she looks verry intrested !i attateched new Connector Pinouts from the Cards PLL and Sythesizer measured with my new rizercardsi will try to follow DaJMasta hints lets see.best wisheskai

author: Potmj
author_rank: Newbie
timestamp: August 21, 2020, 03:39:07 am
content: Hi Folks,Has anyone found a copy of SRC_COR.BAS yet?I have an R3765CH which seems to have an unlevelled output, regardless of the <SERVICE MODES><SOURCE CORR> ON/OFF setting.I am also missing <EDIT> so expect I need to be able to build a floppy image of P/N PR37670001-FK to load it.Does anyone have an Editor image?Lastly, the programming manual identifies commands PEEK and POKE, but they are not documented. Are they documented in the service manual which I don't have?Many thanksMichael

author: bob91343
author_rank: Super Contributor
timestamp: August 21, 2020, 04:50:36 am
content: I own models R3762AH and R3961B. I don't know if they are working properly but frankly they are too big and awkward for me. Does anyone have information on them?

author: kjk24
author_rank: Regular Contributor
timestamp: January 31, 2021, 01:07:19 pm
content: still not solved,only some infos to share with you.at my device-YTO is stable at 4.4GHz and has around -2dBm output,i dont understand here the maintenance manual, the setting for the YTO is not clear for me. 4.4GHz or 4.44Ghz ?- @Hold, span0 the syntesizer is locked and on all frequency up to 8GHz stable.if the span is small (200MHz) and sweep is slow @10Hz it is still locked.but when the span is larger the frq jumps somtimes for and backward, if the span is large and sweep i faster it get out of lock and sythesizer is unlocked.then i have to reboot and bring it emidently to 0 span and 10MHz otherwise its Syth. unlock again.the synth. who mix the first Lo get the jumping values digital i into the two dac.best wicheskai

author: Gyorgy Albert
author_rank: Contributor
timestamp: October 07, 2021, 11:20:52 am
content: Hello All,I recently activated my R3767CG, which was sitting on the shelf for more than 10 years. Of course, the 3.6V RAM battery was empty. I replaced it, but I am still getting the RAM error at the start-up test. I know that for several Advantest analyzers the RAM reset procedure is known (I also used similar procedures for the other Advantest analyzers), I tried all documented key combinations (found in the documents of the Advantest instruments IO group), but none works for my R3767.Is there anybody who can help me with the procedure for the R3767? I asked the company from where it was purchased (about 20 years ago) if they can help me, on return they sent me an offer for repair (I have to sit down when I saw the figure). We paid at that time a little fortune to them, and I expected to get some help. But it seems that it is not possibleThanks in advance,Gyorgy

author: esoteq
author_rank: Newbie
timestamp: January 26, 2022, 08:24:20 am
content: Hi Kai,still reading this sometimesI had the same problem. When trying to fix it YIG failed finally.I scrapped it and used the front panel to a faulty R3565, which now works great.But I had suspicious finding. The level from the comb generator to the ch samplers is low.I think it should be at least > 5dBm but was c. -5dBm. Check that ...your opinion ?And (hence) the level of it from the R-(sub)sampler to the PLL creating 840kHz IF was very very low. PLL might have hard time to lock on it ?In my case it locked sometimes temporarily to a wrong harmonic.Some of the elco's had also high ERS. Bought new elco's, but the YIG failed before getting them.I have all the remaining part for free it needed.The input directional couplers are very good for feeding bias in testing active devices.ErkkaOH1NS

author: kjk24
author_rank: Regular Contributor
timestamp: February 12, 2022, 09:56:34 pm
content: Hi,My unit is still on the bench, i can measure it for you to compare it.

author: Gyorgy Albert
author_rank: Contributor
timestamp: January 27, 2023, 10:32:17 am
content: Hi kjk24,Have you made any progress with your R3767? I also have mine on the bench, so if you need some measurements to be taken, just let me know.BR,Gyorgy

author: kjk24
author_rank: Regular Contributor
timestamp: February 18, 2023, 07:04:46 am
content: Hi Gyorgy,I have to switch it on first after a time ,lets compare your unit errors with my

author: williamlee
author_rank: Contributor
timestamp: July 23, 2024, 10:11:39 pm
content: HiIf you could, email me the R3767 service manual, please. Best Regardswilliambu2ah@gmail.com

author: williamlee
author_rank: Contributor
timestamp: July 23, 2024, 10:54:41 pm
content: Albert, did you solve this issue? I have the same with you.

author: kjk24
author_rank: Regular Contributor
timestamp: July 24, 2024, 04:39:36 am
content: Hello, not done anything on that 👎no time ... Still on the bench updsidedown 😂

author: coromonadalix
author_rank: Super Contributor
timestamp: July 24, 2024, 10:45:59 am
content: PLS @ OP don't put boards on white foam .... static ....