Siglent SSA3021X TG Track Generator DIED repair tips ? - Page 1
Forum section: electronics / testgear

author: oz2cpu
author_rank: Frequent Contributor
timestamp: July 15, 2025, 09:37:08 am
content: I am crying, please help me get happy again,my Siglent SSA3021X TG Track Generator just DIED !no output, only some weak wierd glitches can be seen on the output,the SA input works fine,I think it happened during antenna to antenna gain sweep tests, open dipoles,and a friend came by, touched one of the antennas, and this way ESD zapped the TG output.Darn it, have anyone tried to self repair the TG output ?is it a normal thing it will burn by ESD ?normally it is not a problem for myself since i protect my self for ESD,but when a friend come by and just touch stuff before i could yell stop..

author: KungFuJosh
author_rank: Super Contributor
timestamp: July 15, 2025, 03:08:37 pm
content: Is it still under warranty? If so, I'd send it in before attempting anything yourself.

author: coromonadalix
author_rank: Super Contributor
timestamp: July 15, 2025, 03:45:33 pm
content: send your friend a new replacement bill loll he will learn his lessonas written if under warranty try an exchange, if not ask Siglent and check for service centers, could be expensive or notif under warranty you open it, you know you put yourself out, but you can check parts / id's some of them, and maybe try to schematize the output sectioni did for an scope who got 2 inputs blown, but left with some questions, i noted all the possible parts, will order them later ...it can be simple or very complicated and fragile, you can mess your SSA ... pretty badly

author: oz2cpu
author_rank: Frequent Contributor
timestamp: July 15, 2025, 04:39:13 pm
content: it is not under waranty , and ofcourse I dont expect siglent to be to blame for ESD, that is user error,if this is ESD, i expect others have also tried this ? and can reveal the outcome of a DIY repair attemptmaybe i can find pictures or videos of that TG section online, and this way have a "look" before open it

author: oz2cpu
author_rank: Frequent Contributor
timestamp: July 15, 2025, 04:50:00 pm
content: look what i find : see atteched pictureESD diodes missing !!so that makes the TG output very sensitive to ESDalso see in this video af 12 mins, the TG is a stand alone module,maybe i can purchase this as a spare part ?

author: oz2cpu
author_rank: Frequent Contributor
timestamp: July 15, 2025, 05:09:20 pm
content: anyone know what U68 is ?

author: Grandchuck
author_rank: Super Contributor
timestamp: July 15, 2025, 06:06:52 pm
content: BGA2869?Usually, ESD takes out inputs, not outputs.

author: oz2cpu
author_rank: Frequent Contributor
timestamp: July 15, 2025, 06:37:38 pm
content: u68 is not an amplifier but an RF switch, the question is what typeone suggestion could beas169-73lfBut it is specified 300kHz to 2.5GHzand this SSA handle 10kHz to 3.2GHz (same board 2.1 GHz and 3.2 GHz models)>Usually, ESD takes out inputs, not outputs.ESD can take out any port you zap to, inputs or outputs

author: nctnico
author_rank: Super Contributor
timestamp: July 15, 2025, 07:14:30 pm
content: Is there no package marking at all on the chip? Every now and then I dive into RF equipment and putting the package code into Google has been surprisingly helpfull in many cases.

author: oz2cpu
author_rank: Frequent Contributor
timestamp: July 15, 2025, 07:17:46 pm
content: this picture is from daves video,chatgpt say that part number reads 73I cant really see that 73 :-)and it ONLY say it can be Skyworks AS169-73LF

author: nctnico
author_rank: Super Contributor
timestamp: July 15, 2025, 07:31:38 pm
content: Time to take your spectrum analyser apart then. Maybe yours has the ESD diodes installed. Or it may be entirely different. I have the feeling the equipment Dave gets are early models which regulary differ from what ends up in the hands of consumers.

author: tautech
author_rank: Super Contributor
timestamp: July 15, 2025, 08:11:52 pm
content: Quote from: oz2cpu on July 15, 2025, 09:37:08 amSSA3000XTG spec:Output maximumreverse levelMean power:30 dBm,DC: ±50 VDCHave you tried a Factory Preset ?

author: Martin72
author_rank: Super Contributor
timestamp: July 15, 2025, 09:53:49 pm
content: Quote from: tautech on July 15, 2025, 08:11:52 pmIf there are diodes for protection at the output, which I hope is the case, at least one of them will be defective if the maximum voltage is exceeded, and a defective diode usually causes a short circuit, which could also explain the current signal.

author: tautech
author_rank: Super Contributor
timestamp: July 15, 2025, 10:08:03 pm
content: Quote from: Martin72 on July 15, 2025, 09:53:49 pmWe haven't seen one, yet a screenshot showing the TG menu with levels and TG ON with a TG to RF IN connection is so easy to do and the standard sanity check for troubleshooting analyzer faults.Words are words, screenshots show the truth.

author: Martin72
author_rank: Super Contributor
timestamp: July 15, 2025, 10:20:27 pm
content: QuoteDo you have doubts about his statement?Withthistopic creator, I assume that he knows what he is doing, seeing, and writing...

author: tautech
author_rank: Super Contributor
timestamp: July 15, 2025, 11:53:50 pm
content: Quote from: Martin72 on July 15, 2025, 10:20:27 pmAlways, as an authorised repair center for Siglent equipment it is our job to initially collect as muchrealdata as possiblebeforeany possible return for repair.

author: TurboTom
author_rank: Super Contributor
timestamp: July 16, 2025, 07:18:33 am
content: Before attempring anything else, you may want to check the "Pi" attenuator resistors located between the DC blocking capacitor and the output RF switch.The RF switch itself is driven with a negative control voltage via a pair of BAR63-02V PIN diodes (located at the other side of the board), hence you've got to look for a component that's specifid to be compatible with this driving scheme. The Macom MASWSS0181 would be such a candidate. Another hint is that the output to the Pi pad (common switch contact) is DC coupled. It's not absolutely clear if the Macom is the original component but there's a pretty good chance that it will be working in this configuration.Another candidate would be the HMC595A but it lacks the tolerance for negative/differential driving scheme and requires DC blocking capacitors on all RF ports.My repair approach would be to remove the switch (important: pre-heat the board from the rear for the job, hot air from the top alone just won't do it, and the Rogers RF PCB material isn't really known for its mechanical robustness...), jumper pin 3 to 5 to get a direct link to the HMC307 attenuator output and then check if the TG is working again. If it was only the RF switch that got damaged, this should work and you can replace it. If the damage continues further up the signal path, things may become awkward, but the next thing I would try is jumpering the step attenuator to figure out if the HMC313 output driver is still doing its job. Further up the signal path, I wouldn't expect any damage to be present.Good luck and success with your repair job!Cheers,Thomas

author: oz2cpu
author_rank: Frequent Contributor
timestamp: July 16, 2025, 08:31:31 am
content: that is exactly my idea TurboTomcan we have a confirm of the RF switch part number ?anyone ?Meanwhile : i try to order a whole new TG board, lets see the spare part cost

author: tautech
author_rank: Super Contributor
timestamp: July 16, 2025, 10:10:31 am
content: Quote from: oz2cpu on July 16, 2025, 08:31:31 amNot possible, all SSA PCB's are calibrated as a set.

author: coromonadalix
author_rank: Super Contributor
timestamp: July 16, 2025, 01:36:43 pm
content: i would say find all datasheet of the parts and try to draw some schematic ?

author: oz2cpu
author_rank: Frequent Contributor
timestamp: July 16, 2025, 01:57:16 pm
content: to tautech : TG board can be purchased as sparepart, and it is quite cheapI just got reply from my reseller. no need to think so much about calibration,since the TG normally jumps a few db up and down all over a full span,it's own raw response is clearly calibrated using the 1dB step attenuator,if used for something more serious the spectrum analyzer input is used to software zero the ripplein the frequency area your work, then the curve gets perfectly flat and fine.to coromonadalix : no need for schematic, the signal path is very clearand dave's video show all there is to know about this TG unit.the last part is an RF switch, so far we have not seen a confirm in its partnumberby the way while we are talking about the TG,it makes me a little bit sad i can not use the TG as a signal generator,in zero span its output could have been turned on all the time,but that is not the case, for some funny reason it is pulsed in zero spanmaking it impossible to use it as a signal generator for anything but its own SA input.

author: Rubo
author_rank: Regular Contributor
timestamp: July 16, 2025, 02:10:36 pm
content: Shahriar (The Signal Path) has a review/teardown of it, might want to take a look at his video to see if it has more details.https://youtu.be/Fn7uaEVeOPk?si=Mq9R6jJZeCP3_zys

author: tautech
author_rank: Super Contributor
timestamp: July 16, 2025, 02:13:16 pm
content: Quote from: oz2cpu on July 16, 2025, 01:57:16 pmOkay, for Plus models all PCB's are a calibrated set.Good info, I'll remember that.

author: tautech
author_rank: Super Contributor
timestamp: July 16, 2025, 02:16:52 pm
content: Quote from: oz2cpu on July 16, 2025, 01:57:16 pmBeen a few years since I had the earlier SSA3032X but I'm sure you could set the TG to a Zero Span sinewave source but they were never very accurate level wise but didn't need to be as Normalise corrected for level across the sweep.Someone with a working unit should check this to confirm.

author: oz2cpu
author_rank: Frequent Contributor
timestamp: July 16, 2025, 03:25:02 pm
content: you are right on many other modelsthe TG in zero span can be used as a signal generarorthe accurary over full band is normally about +/-1dB so not bad at all,offcourse far from what a real signal generator will do..This model here, turn on/off the output in zero span mode in sync with screen update,why it is done like that i dont know or understand,but the side effect is simply we cant use it as a signal generator, and that is a little bit of a loss of features,

author: tautech
author_rank: Super Contributor
timestamp: July 16, 2025, 03:38:17 pm
content: Quote from: oz2cpu on July 16, 2025, 03:25:02 pmThe real spec from the datasheet is:Output flatness +/-3 dBHowever some units are much better.

author: TurboTom
author_rank: Super Contributor
timestamp: July 16, 2025, 08:43:50 pm
content: Quote from: oz2cpu on July 16, 2025, 08:31:31 amLook at this thread:https://www.eevblog.com/forum/testgear/ssa3021x-input-blown/msg4807826/#msg4807826I guess this confirms the choices of the components. Since you can also purchase a replacement PCB, you can approach the job relatively relaxed since there's little to lose...

author: Martin72
author_rank: Super Contributor
timestamp: July 16, 2025, 08:59:38 pm
content: QuoteThere are no protective diodes visible in the pictures in the thread either, hm...

author: tautech
author_rank: Super Contributor
timestamp: July 18, 2025, 07:25:36 am
content: Quote from: tautech on July 16, 2025, 02:13:16 pmUpdated info from Siglent:All PCB's in all SSA/SVA or X-R models are calibrated as a set.If a TG PCB can be sourced and NOT from a calibrated set its stimuli error level will be 6-8dB.

author: KungFuJosh
author_rank: Super Contributor
timestamp: July 18, 2025, 04:32:22 pm
content: Quote from: tautech on July 18, 2025, 07:25:36 amSo what's the cal procedure?

author: tautech
author_rank: Super Contributor
timestamp: July 18, 2025, 10:43:30 pm
content: Quote from: KungFuJosh on July 18, 2025, 04:32:22 pmFactory secret.Equipment used for full instrument Cal with their Cal script is:SMB100ANRP18A33500BIIRC you can add a TG level offset which one could use to correct for TG level inaccuracy.