Today I was going through some of the documentation with my TinySA to learn more about it. Running a self test errors starting showing up and I would like to know if I am the cause of the problem or if there is something wrong with the unit. Every time I run the test Tests 3, 7, and 12 fail. Pictures of the screen are attached. Sometimes at least one other test will fail too. Have I lost one of my favorite tools? I just recently upgraded to tinySA_v1.3-325-gac759f9 and did not have the problem when I upgraded. Any help/thoughts are appreciated.

Something I just tried changed the results. I did a factory reset and then set the frequency range to 100 - 150 MHz and reran the test. Only Test 12 Attenuator failed.

Can you do the test as described here:?
and post a picture of the final screen showing the green line?
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Sorry, I thought I posted that as a reply to the original post. Here it is. Thank you for such a fast response.

Indeed, the attenuator is blown up.
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Did you run the levelcalibration ?

Jos

Today I was going through some of the documentation with my TinySA to learn more about it. Running a self test errors starting showing up and I would like to know if I am the cause of the problem or if there is something wrong with the unit. Every time I run the test Tests 3, 7, and 12 fail. Pictures of the screen are attached. Sometimes at least one other test will fail too. Have I lost one of my favorite tools? I just recently upgraded to tinySA_v1.3-325-gac759f9 and did not have the problem when I upgraded. Any help/thoughts are appreciated.

Yes, I did more than once. Tests still fail. Based on what I have seen while researching, I think I have somehow damaged at least part of the attenuator circuit. Don't know how, but if it is that sensitive I may have to find another tool. :-(

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wrpowell2002,? I have the very similar (surprisingly similar) attenuator results.?
Did you have the to ports connected to each other during the firmware update?? ?
I'm thinking possibly the transceiver possibly outputs a high level unintentionally during the update.? I can't think of anything else I did that would cause the damage in my case.? ?It also seems odd if the attenuator is blown it isn't much worse that the test results show.? I'm not familiar with the attenuator component in this device but hardware attenuator I've seen damaged are usually open circuit not just off by a few dB.? ?
I find the device works better if you do NOT do the level calibration.? in my case only the attenuator step fails if I first reset the level calibration.

??

The level calibration fails when the attenuator is blown.
You can perform a manual level calibration that avoids the negative impact of the broken attenuator
Connect two SMA
Enable CAL output at 30Mz
Set low input mode, center 30MHz
set CONFIG/EXPERT CONFIG/LEVEL CORRECTION/INPUT LEVEL/-25

The attenuator consists of multiple stages, 0.5, 1, 2, 4, 8 and 16dB
Yours seems to have blown the 2 and 8dB stages.

During a FW upgrade the transceiver can not output a high level signal.

Confirmed.? Can use manul attenuation to avoid the bad combinations.? I found the attenuator ICs on ebay so plan to attempt repair. Also ordered 2nd tinySA.? Useful to have one as sig-gen while other one is SA..

Thank you Erik, I performed the steps you recommended and now when I run the self test everything passes except the attenuator test. I guess that will have to do for now. Don't understand how this failure could have happened, but I am certainly not an expert. I have not hooked anything up to it with higher power than I thought it should deal with, always less than 1 mW. Will have to do some thinking and research before deciding on repairs or replacement.

Take it from someone who learned it the hard way (me):? it's critical to use a DC block and an external attenuator (maybe around 20db) to prevent accidental damage to the onboard attenuator.? I inadvertently blew out the attenuator on my first TinySA, even though I was careful to not exceed the recommended maximum voltage.? Obviously I wasn't careful enough.? My penance was buying another TinySA, and I've had no trouble since, and have used the TinySA a lot.

Thank you Steven. I think I will replace my unit and maybe try to get the one I have repaired somehow. I did hook up an HT on low power (2W) through 50 dB attenuator which I thought would be enough. Evidently it was not. I did not think of a DC block and will use one if/when I get the replacement. I appreciate the information.

I've made some small improvements in the WARNING section of the first use guide:?https://tinysa.org/wiki/pmwiki.php?n=Main.FirstUse?

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On Wed, Dec 22, 2021 at 06:44 AM, Erik Kaashoek wrote:

I've made some small improvements in the WARNING section of the first use guide:?https://tinysa.org/wiki/pmwiki.php?n=Main.FirstUse?

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Erik,

It might be helpful if this was printed on a piece of paper and included in the TinySA shipping box.




Roger

On Wed, Dec 22, 2021 at 07:38 AM, DAVE REISER wrote:

?

I only have one hand, so I can’t repair it.? Who can?

?

Dave,

By the time you pay for the parts, someones time and the shipping costs both ways it may not be worthwhile. You might consider buying another one and using the broken one as a signal generator.

Those considering a repair should read this post on where to get parts and how to desolder/solder part.
/g/tinysa/topic/85800920#5771

Roger

Hi,

There are some people who do repairs and alignments on other peoples' gear. I am one. But I have no experience 'molesting' a tinySA and so I will not offer. Dave may find somebody here who will do it.

73,

Bill KU8H

bark less - wag more

Dave - I attempted to repair mine (you can buy the attenuator chips off of eBay).? The tools needed are a hot air rework station, solder paste, and a powerful magnifying glass.? Despite having all the tools needed and 40+ years as an electronics tech, I failed.? The attenuator chip is exceedingly tiny and the entire assembly fragile enough that the solder pads on the board couldn't survive the chip replacement.? These boards are built by robots.? If you have the tools it's certainly worth a try, though.? Worst outcome is a slightly bruised ego and you've got to proceed to buy a replacement.