Advantest R3463 trouble (solved)

[Maurizio1957]

Hi Ed, you hit the bullseye! Today I tried to turn on the SA, and it didn't start; i tried heating the top 2 tabs with a hair dryer and it worked.
Noise floor was higher than normal, but in a few minutes it dropped  down.
Faulty capacitors all around? I think I have to change them all, not only in the power supply.
Ciao, Maurizio

[Fraser]

My similar model Advantest SA had failed (leaking) electrolytic capacitors in the power supply DC-DC converters, Processor PCB and RF PCB ! Basically all of the electrolytic capacitors had either failed or were starting to fail 

[edpalmer42]

Hi Ed, you hit the bullseye! Today I tried to turn on the SA, and it didn't start; i tried heating the top 2 tabs with a hair dryer and it worked.
Noise floor was higher than normal, but in a few minutes it dropped  down.
Faulty capacitors all around? I think I have to change them all, not only in the power supply.
Ciao, Maurizio

What is a 'tab'?  I don't know what that refers to.

Actually, what you're describing doesn't sound right.  Heating it to make it work is the opposite of what you experienced earlier.  But you still might be dealing with either a bad component that has become sensitive to temperature, or maybe it's just a solder joint that has gone bad over the years.  Power transistors and connector pins are famous for unsoldering themselves over time, particularly when they experience heat from the current flowing through them.  I'd recommend a long, boring session with a powerful magnifying glass to inspect the solder joints near where you applied the heat and all the connectors.

Have you removed the processor board completely?  If not, have you checked all the mounting screws to make sure they're tight?  Normally, a loose screw would cause random problems rather than the repeatable one you're seeing, but these things can be sneaky.

I also see a DIP switch and a few socketed chips on the processor board.  It would be a good idea to switch all the switches a few times and to ease the chips out of and back into their sockets.  Also, unplug and replug all the cables.  Of course, do that with power off.

Ed

[Maurizio1957]

hello Ed, this time Google didn't do a good translation. Tab => board...
>I also see a DIP switch and a few socketed chips on the processor board.  It would be a good idea to switch all the switches a few >times and to ease the chips out of and back into their sockets.  Also, unplug and replug all the cables.
Done.
I'll do more heat/cold tests.

Maurizio

[Maurizio1957]

Hello everyone.
I would like to know if this characteristic of the R3463 is normal or not: if I connect the 30 MHz reference to the input, and I set the input attenuator to -20 dB, -30 dB etc. I always see the peak at -10 dB, and the noise floor rises. see pictures.

 On the screen, the reference is always 0 dB. ( Markers off ).
I would have expected to see the peak drop in steps of 10 dB, or see the reference at the top of the screen change to -10, -20 ... depending on the attenuator setting.
I couldn't find anything in the manual about this.
Thank you all, Maurice

[Gyorgy Albert]

Hi Maurizio,
Yes, what you see is normal. By default the analyzer is switching the input attenuator (at RF level) automatically, together with its internal IF Step Attenuators and IF Step Amplifiers (both at IF level). All this is calculated according to the set Ref Level. You can change the control of the input attenuator to manual (as you did), but on the IF level the Step Attenuator and Step Amplifier is still controlled automatically by the analyzer (and you cannot change them to manual control). Since you kept constant the Ref Level, but changed the input attenuator to manual, and increased the RF attenuation, the analyzer compensates this attenuation with the increase of the Step Amplifier gain (to keep the dynamic range on the screen related to the Ref Level and the number of vertical divisions multiplied with the set dB/division). And of course this increase of gain will increase the level of the noise too. This is what you see. 

BR,
Gyorgy

[Maurizio1957]

Hi Gyorgy, thanks for the reply, now this is clear.
Now I have another issue: I see strange peaks at narrow span, both with the 30 MHz calibrator and with an external source.
These peaks seems related to the time of the span rather than the amplitude of the span




and, when I start the autocal feature I see this message:

" IF Step amp failure. Pls verify external reference and setting, then repeat " 
I have checked the 10 MHz output on the rear panel with a o'scope, and the signal is there, I don't know what " setting " check...
I have these instruments: multimeters, CRO up to 50 MHz, Marconi signal generator up to 500 MHz and another sig gen from 1,3 to 3 GHz, DG8SAQ VNA, hammers and skrewdrivers...
Thanks to all, Maurizio

[Gyorgy Albert]

Hi Maurizio,

Normally if you don't have any problems, you should see a clean carrier in the middle of the screen, without those spurs. The spurs indicate that you have some unwanted modulation on the calibration signal, but this appears not at the generation of the cal signal (not at the BNC output). Most probably somewhere on the analyzer input path (1st IF, 2nd IF and so on). It is a typical power supply/filtering problem, and it is very common for the Advantest analyzers of that age. I also had a similar problem, which leads to user calibration errors. Please see the images below: 001,002,003 is the cal signal in different span and dB/division view (measured with a good working analyzer). In zero span, the analyzer performs like an oscilloscope, you will see the demodulated signal. You can see, in zero span it is a straight line, there is no noise over it. The zero span is very handy, to determine the cause of the spurs/noise. In the pictures B004 through B007 there are the captures of the same calibration signal taken with my defective analyzer (Advantest R3273). In zero span, with 10 dB/division it also can be seen (this should be a straight horizontal line) that there is a ripple. In the last picture I triggered to the video signal (the resolution is 0.5dB/division), so it looks like an oscilloscope image, and is clear that there is an additional modulation detected, the period can even be measured with the help of the markers (the power supply is a switching mode one, so we do not chase 50 Hz or harmonics, the frequency is in the range of multiple of 10kHz). In the end the solution was to replace a lot of capacitors, first all inside the power supply, and also some others in the different modules.

If you have the possibility to use another analyzer, and measure the signal on the receiver path of your R3463, you can trace down where the most part of this noise appears on the path. You have to keep the analyzer with zero span (tuned to 20/30 MHz, depending on the analyzer, and the CAL signal connected to its input), and you can measure along the path (1st IF, 2nd IF, etc.) with the other analyzer the signal (also in zero span). You will find where this additional modulation appears.

This unwanted modulation causes the step amplifier/attenuator calibration failure. During the user calibration, when the IF is calibrated, the analyzer keeps the input RF attenuator at fixed value, and switches some IF step amplifiers and attenuators with small increments (0.1/0.2/0.4/0.8 dB). As it can be seen in images the ripple causes a change in amplitude of the demodulated signal more than 1 dB, which confuses the analyzers measurement/calibration routine. It measures a reference level first, makes a small attenuator step change, and when measures again, due to the ripple, it will detect an over range value. So it will report an error.

[Gyorgy Albert]

Hi all,

I am following this topic, because I also have an Advantest R3272, which belongs to the same family as the R3463/R3465. The platform is the same, the RF decks of the units are different (3GHz/8GHz and 26.5 GHz version). I was a bit annoyed because I have never seen a R3272 with the Basic controller options, or the RX control options, which makes the R3560 family controllable by the analyzer. And I would be interested to enable this option for my analyzer. I recorded the boot sequence (indeed, 60 frames was necessary to not miss anything, thanks Ed), and I noticed the following differences in my unit compared to what is listed by Ed and Maurizio:

Read system files ...      >> OK
LOADING ATOS.SYS      >> OK
LOADING INIT.SYS      >> OK
SYSPATH = SD:/                >> OK
LOADING MONS.X      >> missing
LOADING GPIB.X      >> OK
LOADING STATUS.X      >> OK
LOADING REMOTE65.X   >> in my case is REMOTE72.X
LOADING SIOCTL.X      >> OK
LOADING ROMTASK.X      >> OK
LOADING DH.X         >> missing
LOADING VOO.X      >> OK
LOADING MENU.X      >> OK
LOADING PCCLOCK.X      >> OK
LOADING SYSCONF.X      >> missing
LOADING SRM.X      >> OK
LOADING ISUPER.X      >> OK
LOADING MMM.X      >> missing
LOADING CMPNSTR.X      >> OK
LOADING DFM.X      >> OK

So obviously there are some differences. Ed wrote earlier, that the system files (these above) can be copied to the memory card. I have not found any information related to this, I checked all the user manuals (R3463/R3465/R3272). I would really appreciate if someone can give me information, about how this can be done. I tried all the possibilities, but I did not succeeded.

There is a DIP switch on the daughter board which sits over the main board (in mine the switch number 7 is in ON position, all the others are in OFF), I have not tried yet to change these settings. Maybe, some special modes (maintenance maybe) can be activated/enabled with these switches. In the case of other Advantest analyzers (R3267, R3273, R3132/R31xx), where there is a flash disk, and the content can be read/listed, there is a MAINTE.X executable/library, which is loaded at boot, and this is responsible for the maintenance mode. Since in this family this file is not listed in the boot sequence, for sure the Maintenance Mode is not available. It would be helpful if we found this out, because than we could do some service mode calibration.

BR,
Gyorgy

PS. I dumped the content of all 4 eproms of my R3272, the files are available on the Advantest list of groups io. If someone needs them, just let me know, I can send them by email, or upload here (they are not too big)

[edpalmer42]

It was many years ago that I copied those files.  I didn't think I'd ever need to do it again so I didn't take any notes.  I seem to remember that it felt like a bit of a hack.  I know it was related to the path listed in the bootup info so probably SD:/ .  It was something like 'copy all from SD:/ to A:' where A: is the PCMCIA (or Compact Flash or even SD card via adapters).  I'll see if I can reinvent that wheel, but it'll take me a day or two.

Ed

[Maurizio1957]

After a long stop I'm restart work on this SA...
I removed the lower board for capacitors check I'll do in the next few days ,  here I have some pictures.

[Maurizio1957]

More pictures...
A question: why there are on the same board SMD and through hole capacitors?
Happy new year to all by Maurizio!!

[Maurizio1957]

Hi all, update:
changed all the electrolitic capacitors in the             
 power supply and all the boards of the device with new
smd (where possible) or  through hole capacitors;
currently the problem of blocking on start-up seems to have been resolved, the SA starts regularly;
the self-test passes without problems, previously it gave an error on the input attenuator or
  on the medium frequency channel;
  the problem remains on strange artifacts seen using a very narrow rbw,
  I did a test by listening to the mid-frequency output with an ssb receiver
  to 21.400 MHz, and I hear a hum that may coincide with the peaks you see
  on the screen ( some pll doesn't work well, I think) ,  now I don't have the
  instrumentation to do this check on the medium frequency of 421 MHz.
   The images are made with a scan time of 1 second and 5 seconds.
   Cheers, Maurizio

[Gyorgy Albert]

Hi Maurizio,

Try to brake the IF stages and instead of using the IF output from the previous higher frequency stage, inject signal from an external signal generator. You can do this on both 21.4 and 421 MHz. You should be able to determine from where is coming this extra modulation. On zero span with trigger on video, you should see demodulated signal. The extra modulation should be visible there.

There is also a high frequency 1st IF  (above 3 GHz) for the low band of these spectrum analyzer family (in your R3463 this is the only high frequency path, since it is the 3 GHz version). The LO for this is usually made with an ERA monolithic amp, which usually fails. But the PLL of this oscillator could also cause the trouble (the free running frequency of this oscillator is detuning in time, because of the aging of the substrate material, and the locked PLL tuning voltage could be on the limit). 

The loop circuits of the first microwave oscillator (YIG) is quite complicated, you should isolate the problem, and it would be great if not this one is faulty.

There are some topics here on eevblog about the oscillator with the ERA, the R3272/R3463/R3465 is very similar to the R3267/R3273 family (and some circuit solutions are shared also in the R132/R3162 family):

https://www.eevblog.com/forum/repair/advantest-r3273-r3267-repair/25/
https://www.eevblog.com/forum/repair/advantech-r3162-frequency-drift-rf-test-fail/

BR,
Gyorgy
 

[Maurizio1957]

Hi Gyorgy, I did as you said and maybe I found the problem!
In photo 4 I have injected a 21.400 MHz signal into the third medium frequency channel:
there are no traces of anomalous signals;
in photos 1 and 2 I enter with a 421 MHz signal in the second medium frequency channel:
I see the usual peaks as they appear when viewing a signal with narrow RBW placed
at the input to the SA, like in photo 3.
So the problem could be  in the 400 MHz local oscillator for the third medium frequency conversion!
Stay tuned... 

[Gyorgy Albert]

Hi Maurizio,

Good that you made progress. The mixer which receives the 421 MHz IF signal is in the middle screened compartment of the RF deck ( see your picture above, where you have noted 421MHz PANN POST). One of the side SMB connectors receives from the synthetizer module the LO signal. It is in fact 200 MHz, and there is a doubler inside the middle compartment (and some filters of course), so it will drive the mixer with 400 MHz.

If you suspect the 400 MHz LO, you can use the same idea, and drive the doubler instead of the signal from the synthe with an external signal with the same level. It would be a good idea to use tye same reference frequency for the R3463 and your RF generator. Either use the 10 MHz ref output from the SA, and connect it to the ref input of the generator, either reverse way.

Just one remark. I am sure that it is obviously clear, but the only variable frequency oscillator is the YIG, for the first mixer ( in fact, in the first LO loop circuit there are several variable frequency oscillators, but from the system point if view we can consider that only the YIG has variable frequency). All others LO-s have fixed frequencies. So if you broke the path, and entered external IF signals (21.4 MHz, 421 MHz), it does not matter which center frequencies you set from  the SA front panel. I suppose that you set the 21.4 MHz and the 421 MHz, just to visualize clearly on the pictures which of the IF paths are tested. Right?

Best regards,
Gyorgy

[Maurizio1957]

Hi to all
after a lot of work I think I have solved the problems of this device.
The pulses that are in photos n.1, 2, 3 were caused by the 200 MHz oscillator slightly out of frequency.
I made these tests: entering from the rear EXT REF 10 MHz IN/OUT with a signal from a Leo Bodnar GPSDO and varying
the frequency of a few Hz the pulses on the screen increased with a lower frequency or decreased with a frequency
  higher than 10 MHz.
  I disassembled the PLL board for the n-th time and I tried to slightly move the trimmers of the vco at 200 MHz, and these pulses are
  disappeared... maybe it was just a oxidized contact??? I don't know...
Now everything works fine!
Greetings, Maurizio