Register to reply

Is this tantalum capacitor damaged?

by gnurf
Tags: capacitor, damaged, tantalum
Share this thread:
gnurf
#1
Feb2-13, 03:09 PM
P: 330
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?
Attached Thumbnails
_failed_tantalum.jpg  
Phys.Org News Partner Engineering news on Phys.org
Tricorder XPRIZE: 10 teams advance in global competition to develop consumer-focused diagnostic device
Study shows local seismic isolation and damping methods provide optimal protection for essential computing equipment
New filter technology uses inert gas to bore holes in high-quality steel
NascentOxygen
#2
Feb4-13, 10:21 PM
HW Helper
Thanks
P: 5,341
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 web site 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
#3
Feb5-13, 04:07 AM
Sci Advisor
PF Gold
davenn's Avatar
P: 2,648
how does it comapre to the one in the upper right of the pic
the one partly hidden by your enlargement inset ?

Dave

gnurf
#4
Feb5-13, 04:37 AM
P: 330
Is this tantalum capacitor damaged?

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?


Register to reply

Related Discussions
Why does the ICs(AD620AN) gets damaged? Electrical Engineering 11
Tantalum vs Ceramic Capacitors General Physics 5
Looking for information about tantalum carbide Materials & Chemical Engineering 0
Help me….my hard disk is damaged Computers 13
Best solder for tantalum? Materials & Chemical Engineering 1