Is this tantalum capacitor damaged?

[gnurf]

I'm troubleshooting an old (1995) LeCroy scope that has shown some irregular behavior lately ("multiple calibration errors" warnings, display freezes for a while when changing the volt/div and time/div settings, etc), especially after running for a while. I won't bother you with all that—I'm just wondering if the cap in the picture is damaged? The picture quality is not great, but it's the best I could do. I thought it looked worse in a 4X microscope where the bump seemed darker/grey/black in the middle. Any thoughts?

 

[NascentOxygen]

I have no idea, though I can see why you might wonder. Are there others on the board that you can compare with? If you can see a manufacturer's name, maybe try their website there may be photos of their products there.

Good luck! Very disheartening to have to bin a piece of equipment for being unable to trace a faulty component worth a few cents.

 

[davenn]

how does it comapre to the one in the upper right of the pic
the one partly hidden by your enlargement inset ?

Dave

 

[gnurf]

Vishay has tantalum series (e.g. 595D) that look exactly like that:

I'm still not sure if it's a sign of damage or not, but the other similar looking caps on the board do not have this bump, and Vishay, of course, wouldn't put one of their ugliest ducks in a marketing photo. Anyway, I've replaced it now and after a complete disassemble/reassemble it seemingly works again. Time will tell, I guess.

What is certain is that the scope (which I got for free) is not going in the bin any time soon. It's a 500MHz-2Gs/s monster compared to what I had before, and the fact that you can download the complete 400 page manual complete with schematics, BOM list, etc, blows my mind a little bit—very educational! You old heads had it too easy. :)

Edit: Btw, I measured the capacitance once the cap was out of circuit and it was within spec. Google: Is there some definitive capacitor test I could do?

 

[alphysicist]

Based on the information provided, it is difficult to determine if the tantalum capacitor is damaged without further inspection. The irregular behavior of the LeCroy scope could be caused by a number of factors, not just a damaged capacitor. It would be best to thoroughly troubleshoot the scope and rule out any other potential issues before concluding that the capacitor is the cause. If the capacitor does appear to be damaged, it is possible that it could be contributing to the issues with the scope. However, without a closer examination and analysis, it is impossible to determine the extent of the damage and its impact on the scope's performance. It is recommended to consult with a professional technician or engineer for a more accurate assessment of the capacitor's condition.