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Need help identifying component

Need help identifying component

Need help identifying component

(OP)
While soldering a notebook DC jack, my solder iron touched and broke off an adjacent component. I posted a picture at:
http://pages.suddenlink.net/stevensmith/NotebookJackPic2.JPG

Please let me know what this component is and if I will need to replace it for the notebook computer to work.

Thanks,
Steve Smith

RE: Need help identifying component

Looks like a surface mount capacitor, identifier is PC273 (PR379 is a resistor and located to the right).

Yes, you will probably need to replace it to ensure reliable operation. It might work without it, but don't count on it. How did you manage to break it off - they are normally pretty difficult to break off a board. It is hard to say for sure whether the black line in the upper solder pad is just fractured solder or part of the capacitor - if the latter then you need a new one. Look for any markings of the component - you might be lucky because it is quite a big one and has some chance of having some information printed on it.
 

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  Sometimes I only open my mouth to swap feet...

RE: Need help identifying component

(OP)
Thanks for the reply. Unfortunately, there are no markings on the part. I've posted a picture of the underside here: http://pages.suddenlink.net/stevensmith/PC273.JPG

The part broke off when I was trying to solder the jack and while trying to get the soldering iron tip along side of the jack the soldering iron touched the component and apparently heated it up and one side just came loose. When I moved it back down the other side broke off.

Is it possible to solder this part back on? Without markings, is it possible to know what part to replace it with? How are these components attached to the PCB? Do they have leads, or are they just soldered directly?

The notebook will come on(with the battery in), but I have not yet booted into Windows. Unfortunately, my jack repair did not work because it still does not get power from the power jack. I'm going to recheck my connections. Is it possible the jack doesn't work because this part is broken?  

I really appreciate any advice you can give.

RE: Need help identifying component

Nice pictures! Very helpful.

That part is likely a resettable fuse that is a mate to the one above the connector. Notice the large traces that fed that part and the unique Board REF numbers. It is likely undamaged and could be a MAJOR pain to ID correctly. It looks like you got a truckload of plastic off the connector onto it.  Sort of like a nasty fish landing struggle occurred.

Use your soldering iron to clean up the two pads on the board so they have a minimum amount of shiny solder on them.

 Very carefully try to scratch some of that black nasty off the part so its thermal characteristic isn't so altered.  Use a sharp razor blade.


Then set that part back on those two pads UP SIDE DOWN. Heat an end and add a TINY amount of solder.  Wait briefly, 5 secs, and then do the other side.

That should do the trick.

Keith Cress
Flamin Systems, Inc.- http://www.flaminsystems.com

RE: Need help identifying component

It looks like the part is identified as PL26. There is one in the left of the photo that is identified as PL2? (last number not visible).

The black grainy structure of the part in the photo leads me to believe it is a inductor (hence the "L" in the designation which is the convention for inductors). Perhaps a ferrite to supress EMI from traveling out of the power jack. Two of them means they are arranged to block EMI on both the + and - of the incomming power.

Surface mount components are held in place by the solder on the leads to the PC board pads.

If the part is an inductor, then it passes the DC input power and block possible high-frequency noise from traveling out of the notebook/PDA. If you have a ohmmeter, it will measure only a Ohm or two of resistance across it. However, since some of the metalization is missing/torn from each end, it could now be damaged (open circuit).

The solution is hard to call. If it is an inductor or resetable fuse, it could be replaced temporarly by a piece of wire. If a capacitor, replacing it with a piece of wire is going to short something out.

RE: Need help identifying component

The L makes sense. I like that thought too.

I use inductors in lots of my designs and I've just never needed them that big since they usually have low DC resistance so I didn't go there.. But they would certainly be series devices too.

Keith Cress
Flamin Systems, Inc.- http://www.flaminsystems.com

RE: Need help identifying component

Agree it's an inductor.  Capacitors appear to be prefixed with "PC" and resistors "PR."  

TTFN

Eng-Tips Policies FAQ731-376


RE: Need help identifying component

Comcokid,

Good spot on the similar component elsewhere - I missed that. Concur it is probably an inductor. My bad!
 

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  Sometimes I only open my mouth to swap feet...

RE: Need help identifying component

(OP)
Thanks so much for the replies. The "inductor" has continuity from one silver end to the other. My multimeter does not measure any resitance. However, if I touch the probes of the multmeter to the black parts, I can't get any continuity. Since it appears this is an inductor, rather than a capacitor, would I still follow these instructions:

"Use your soldering iron to clean up the two pads on the board so they have a minimum amount of shiny solder on them.
Very carefully try to scratch some of that black nasty off the part so its thermal characteristic isn't so altered.  Use a sharp razor blade. Then set that part back on those two pads UP SIDE DOWN. Heat an end and add a TINY amount of solder.  Wait briefly, 5 secs, and then do the other side."


Since there is continuity from one silver end to the other, it seems this would work. Or, would I be better off to use a wire and if so, would that cause any problems? By the way, this component is approxiamately 5mm x 3m. It looks larger in the pictures, but it's really very small. One other question: I'm using a Hakko 936 soldering station. What temperature should I use to for soldering, both the repair the jack and to replace the inductor?

RE: Need help identifying component

No, follow my instructions.

Do not use a piece of wire.

Use 720F.

Do the best you can with black goo removal. You won't hurt the part. Use tweezers and a magnifying glass.

Keith Cress
Flamin Systems, Inc.- http://www.flaminsystems.com

RE: Need help identifying component

Looks like a large ferrite bead to me, so it would need to be in circuit.
Best regards,

Mark Empson
http://www.lmphotonics.com

RE: Need help identifying component

If it is capacitor, one end is connected to Vcc, the other to GND.

If inductor or fuse then it has no GND connection


----------------------------
Please read FAQ240-1032
My WEB: <http://geocities.com/nbucska/>

RE: Need help identifying component

Looks like the top side is undamaged. Maybe just
solder it upside down.

RE: Need help identifying component

(OP)
Thanks again for the help. I followed the instructions by itsmoked and the laptop is now working great. I'm new to soldering and it's not the best looking job, but it does work. See the pictures at http://pages.suddenlink.net/stevensmith/DellJack3.JPG and http://pages.suddenlink.net/stevensmith/DellJack2.JPG . I'm curious, how should one hold this part still while soldering it? I guess you would use an alligator clip. I didn't have one, so I put a drop of Super Glue on the bottom of the inductor and that held it while I soldered it. I realize this would have caused a problem if the part had to be removed, so next time I'll use a different method. Any suggetions?

As I mentioned in my original post, I was repairing a broken notebook computer jack when I broke the inductor off. This is the first time I have done such a repair. The jack had broken loose from the circuit board. I wasn't sure if I should solder the top or the bottom of the jack, so I soldered both. See pictures at http://pages.suddenlink.net/stevensmith/DellJackUnder.JPG  and
http://pages.suddenlink.net/stevensmith/DellJack1.JPG . So I'll know next time, please let me know what should be soldered, top, bottom, or both? I didn't see any traces on the bottom, but I thought maybe they are in a layer below, or at least the solder would help hold the jack in place.

As mentioned in my original post, the jack repair did not work when I first attempted the repair. I'm wondering, would the broken inductor have caused this? It works fine now, but I resoldered the jack in addition to soldering the inductor back on.

Thanks again for helping out a newby. I hope to learn enough so I can become proficient at repairing broken notebook jacks.

RE: Need help identifying component

A word of warning:

Superglue - cyanoacrylate - decomposes when heated to form some really nasty fumes. I think the chemical name for these gases is isocyanates. Perhaps someone will tell us for sure? I made a mistake a lot of years ago when a circuit trace lifted off a SRBP board and I superglued it back down before soldering it. There was a tiny puff of white smoke and suddenly my eyes were burning and I was coughing so hard that my lungs felt like they were being torn out of my chest with a grappling hook. Epoxy resin is a much safer bet if you need to hold something in place when soldering. Most boards these days use epoxy and glass mat in their construction so the materials are stable at normal soldering temperatures.

The jack looks like the active traces are top surface or on a buried layer in the core of the board and the bottom pads are mainly there to provide mechanical anchoring. There are a number of vias - a conductive paths connecting the different layers visible as small dots beneath the green solder mask. A group are just below (above in the photo) the PR372 legend.
 

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  Sometimes I only open my mouth to swap feet...

RE: Need help identifying component

To solder a small part by hand, apply a very thin film of solder to one pad.  Hold the part down to the board with tweezers, and touch the soldering tip to the solder spool wire to grab a tiny blob of solder on the tip.  Touch the tip to the component and board until the board solder melts with what you just introduced.  Let it cool before moving the tweezers.  Repeat the tiny blob technique with the other side, but no need for tweezers.  If you have flux, use a small dab on the pads, but it's not necessary for minor fix-it jobs.

Scotty already has you covered on the reasons to resolder the jack vias and the use of cyanoacrylates.

Dan - Owner
http://www.Hi-TecDesigns.com

RE: Need help identifying component

You virtually never glue the parts down.  That is reserved for boards that will be soldered in mass while upside down.

Just use the tweezer method as described.

On thru-hole parts, like your connector, you normally only solder the bottom of the board, while it's upside down. You do however make sure that the pin and pad get warm enough to allow the solder to run down the hole with the pin.  Preferably to form a small meniscus on the other side of the board/pin.

Keith Cress
Flamin Systems, Inc.- http://www.flaminsystems.com

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