Little ''problem'' with oscilloscope  - Page 1
Forum section: electronics / testgear

author: Fezder
author_rank: Regular Contributor
timestamp: April 22, 2013, 05:20:39 pm
content: Well, i figured maybe i should i ask this out, i did search answers in/out forum, but no good so far.....but here goes.Matter i simple really, what is best way to measure components in circuit, i know, just plug probe in place (sort of), but i talk about IC pins, especially SMD chips, they are so narrow to probe, well at least ground lead that is. Do you people use any cind of custom hacks, or are purpose-made SMD ''clips'' the best way in these measurements? throught-hole components are not problem, except IC's due the risk of shorting close pins together and creating more damage in circuit.....i hope you understanded my problem, and please, be understanding.

author: free_electron
author_rank: Super Contributor
timestamp: April 22, 2013, 05:38:27 pm
content: Use a probe that has a pogo pin at the tip. if you can get the bifurcated version ( or a 'crown' tip )Those things 'bite' inot a point and will not slip. The tip has a spring in it.other good things to have is a probe-buddyhttp://www.eurekaspot.com/sp.cfm/PROBES/TEK/PPM007.htmlalso these things help tremndously :http://www.home.agilent.com/en/pd-1695688-pn-E2639A/e2639a-micro-clips-qty-4?&cc=US&lc=enghttp://www.home.agilent.com/en/pd-1661803-pn-N2878A/n2878a-general-purpose-accessory-kit?nid=-34384.898997&cc=US&lc=engthe above slides ver the probe tip. it gives it two plastic side tabs that can slide inbetween tqfp pins. this avoids the probe slipping sideways.http://www.home.agilent.com/en/pd-1000000658%3Aepsg%3Apro-pn-E2615A/065-mm-wedge-probe-adapter-for-tqfp-and-pqfp?nid=-34380.536881313&cc=US&lc=enghttp://www.home.agilent.com/en/pd-1000000660%3Aepsg%3Apro-pn-E2616A/065-mm-wedge-probe-adapter-for-tqfp-and-pqfp?nid=-34380.536880406&cc=US&lc=enghttp://www.home.agilent.com/en/pd-1000000657%3Aepsg%3Apro-pn-E2614A/05-mm-wedge-probe-adapter-for-tqfp-and-pqfp?nid=-34380.536879430&cc=US&lc=enghttp://www.home.agilent.com/en/pd-1000000666%3Aepsg%3Apro-pn-E2644A/065-mm-wedge-probe-adapter-for-tqfp-and-pqfp?nid=-34380.536879282&cc=US&lc=engand here's a whole rang of clips and tips :http://www.emulation.com/catalog/catalog.cfm#probingeven up to 10Ghz ...

author: jahonen
author_rank: Super Contributor
timestamp: April 22, 2013, 05:41:02 pm
content: If I need an attachment for ground clip, then I'll just solder a piece of stripped wire somewhere near the point to be measured. Much better than destroyed board due to loose ground clip. But of course it is always better to use completely different probe, preferably active or Z0 probe.Regards,Janne

author: Fezder
author_rank: Regular Contributor
timestamp: April 22, 2013, 06:01:06 pm
content: ah, thanks for replies. i just recently, well actually year ago or so, ground pin really got loose. i was ''lucky'' thought, it shorted 50v/6800uf cap, dont know how it happened but it really freaked me out.

author: PA0PBZ
author_rank: Super Contributor
timestamp: April 22, 2013, 06:06:23 pm
content: Quote from: Fezder on April 22, 2013, 05:20:39 pmIf you are afraid to damage DIP IC's there is always this:

author: Fezder
author_rank: Regular Contributor
timestamp: April 22, 2013, 06:14:03 pm
content: Quote from: PA0PBZ on April 22, 2013, 06:06:23 pmoh yes, i saw those at school, i thought they were only for dismantling purposes, not for measuring, hmm...

author: nctnico
author_rank: Super Contributor
timestamp: April 22, 2013, 11:20:57 pm
content: Back in the old days I used to have a clip-on gadget from HP which showed the logic levels on chips like this one:http://www.ebay.com/itm/HP-Vintage-10528A-Logic-Clip-/200916371926I think I still have it somewhere.On topic: to ground my probe and other equipment to a circuit I solder a piece of used solder wick somewhere to the board. Yes I manage to recycle used solder wick!

author: digsys
author_rank: Unknown
timestamp: April 23, 2013, 01:15:41 am
content: Ah yes, it's a problem spawned by ICs etc becoming smaller and smaller, and more tightly packed. There's been many times thatI've slipped on a tiny / awkward pin, and there really is NO perfect solution (after the fact). But -IF you can have input to the design layout, make sure pins that you "may" need to probe are tied to components or free pads.Sometimes I'll place a 2mm DIL strip 1-2 row, just to have a bulk access point. IF it's not your PCB, then either solder fine wire"tags" or use a tiny, very sharp pin, wired to your probe (if it's not a HF point). Don't worry, HEAPS of techs have this problem :-)

author: ben_r_
author_rank: Frequent Contributor
timestamp: April 23, 2013, 03:42:49 am
content: Good info here, glad I read this thread. Thanks for all the links free_electron!

author: ddavidebor
author_rank: Super Contributor
timestamp: April 23, 2013, 05:20:40 am
content: Another little trick is to paint the smd, so your probe stay much stable and if it move don't short the other pin.

author: Fezder
author_rank: Regular Contributor
timestamp: April 23, 2013, 02:54:41 pm
content: well good that i'm not the only one with this problem, now i just cant find anywhere place selling those spring-type clips sold locally/internationally.....any help regarding this is also appreciated!and about that logic clip, i saw that one on school today. and got 16 pin clip for free, but i really could use other sizes too, like dil-8 and dil-40

author: ddavidebor
author_rank: Super Contributor
timestamp: April 23, 2013, 03:32:11 pm
content: Diy?!

author: Fezder
author_rank: Regular Contributor
timestamp: April 23, 2013, 03:37:52 pm
content: Quote from: ddavidebor on April 23, 2013, 03:32:11 pmWELL, here's language i like, i like DIY very much. at least when i cant afford other (which is very often....)

author: Wuerstchenhund
author_rank: Super Contributor
timestamp: April 23, 2013, 05:43:50 pm
content: Quote from: ddavidebor on April 23, 2013, 03:32:11 pmDamageityourself

author: Fezder
author_rank: Regular Contributor
timestamp: April 23, 2013, 05:51:23 pm
content: Quote from: Wuerstchenhund on April 23, 2013, 05:43:50 pmhaha, true