ID of a component on 22 years old Japanese board

[matura713]

I dropped the board, it hit the edge of my desk and as result 2 of those components in question are now broken.

So, guys, please, check the attached picture and help me understand with what I can replace them.

Here is what I can understand as complete amateur:

* it's most likely Panasonic brand, because I can only find Panasonic EMI filters in such form factor:

https://www.digikey.com/product-detail/en/panasonic-electronic-components/EXC-CET102U/P9830TR-ND/137165

[EDIT1] found even other Panasonic series that visually are better match, even exact match, as form factor:

http://eu.mouser.com/new/panasonic/panasonicelke/

but maybe other companies use such form factor as well and my clue it's Panasonic is not really good.

* it's marked as "F103" and I can find the same component on 4 places on the board, on +5V and +12V input lines and on Audio Left and Right Outputs

What I cannot understand as amateur and for what I need your help:

* Do any of you knows what exact part number is that component marked as "F103" and produced over 22 years ago?

* If no one of you can say the exact part number of that component and assuming it's EMI filter - what are the parameters of such component and how I determine them to choose a proper replacement - after all I still have 2 of those components undamaged. How I can measure their important parameters?

thank you, I am total amateur here, while I have some very basic knowledge of things like resistors and capacitors, etc, I have no idea of EMI filters at all and so sorry if my questions are very stupid, I just broke my board with dropping it and I am looking of way how to properly fix it.

[ataradov]

Retracted. They are filters.

[matura713]

Alex, thank you, but are you sure - I mean "FL" could as easily mean "Filter" and if you look at this:

http://eu.mouser.com/new/panasonic/panasonicelke/

those EMI filters look exactly as the component in question - my understand is that the small component in the center is capacitor.

I guess if it's a fuses, then what looks like small capacitor in the center it's not a capacitor.

[EDIT 2] Alex, changed his mind and so I guess they are indeed filters...

[ataradov]

How badly damaged are they? Can you make a closeup photo of the internals? It looks like it has 3 pins?

[matura713]

I don't have with what to make close-up photo of the internals - only my crappy phone that certainly cannot be used for such task, but yes the pins are 3, if you look the picture here:

http://eu.mouser.com/new/panasonic/panasonicelke/

even if we assume my component is something else, on my board the middle pin (the end of what looks like capacitor) is soldered to ground and the left and right joint 2 adjacent pads on the same trace - without the component the trace is disconnected - that's why now it's not working. I guess I can just solder a wire between those 2 pads, but that's not a proper fix.

[ataradov]

In that case it is LC T-filter. Two inductors in series, and a capacitor to the ground from the mid point.

Just replace it with a jumper across two pins and leave the ground one alone. I don't think there is a reasonable way to measure its parameters.

[matura713]

is there way to measure the 2 not damaged one and determine all necessary parameters for a proper replacement? [EDIT] you replied on this while I was writing... it's too bad I will never be able to restore the board to its original state.

Are there other important parameters than capacitance and cut-off frequency? I believe at least "F103" in the marking has to be 10000pF the capacitance and so only cut-off frequency is not clear, which I guess depends on the 2 inductors surrounding the capacitor.

[ataradov]

Capacitor can be measured directly to verify. I'm not sure why they wold mark this by capacitance, its value is meaningless provided that filter works in general.

They would be ferrite beads, not just conductors, so the only way to figure out their characteristics is to measure frequency response. And capacitance is not really important, as long as you can get the same cut-off frequency.

So if yo have a scope and a frequency generator, it would be a quick test.

Can you identify in what signal path they are located? You may be able to infer some reasonable approximation without any measurements.

[matura713]

no scope, no frequency analyzer, as i said complete amateur. however, i noticed something else in current components that look the same, datasheet:

http://www.mouser.com/ds/2/315/AWF0000CE1-951066.pdf

for example for the one marked as "ELKE103FA", which contains "103" it's said:

Cut off frequency: 0.5/DC

I don't know, you here are the experts, but why they use letters "DC" in the cut-off frequency, maybe when such component is placed on DC lines (like in my case +5V and +12V lines), they need to have such 0.5MHz cut-off as that is relevant somehow for DC. I really don't understand, why Panasonic in that datasheet use "0.5/DC" for cut-off value?!

[ataradov]

I think they just consider frequencies < 1 MHz to be DC. So basically this is to remove any noise.

"Easily discernible part number written by lasers" in features - somebody was running out of things to put into bullet points.

The one you found will work as a replacement. If they are installed in voltage paths, then it really does not matter.

[matura713]

hmm, i found similar looking component from TDK as well, they as well in the marking on the component put only the capacitance:

http://static6.arrow.com/aropdfconversion/9d75a5117dcea7075b7ee830db769db2fab0338e/13094765288272463tf_commercial_power_ach3218_en.pdf

Now, I start to believe, maybe it's some industry standard and in case of such component the 2 inductors are fixed value and they only change the capacitor value to make different characteristics. is that make sense? why both TDK and Panasonic only mark the capacitance otherwise?

[ataradov]

Now, I start to believe, maybe it's some industry standard and in case of such component the 2 inductors are fixed value and they only change the capacitor value to make different characteristics. is that make sense? why both TDK and Panasonic only mark the capacitance otherwise?

I would say, they just use the capacitance as part number for a specific range of devices. I don't think it is universal between different manufacturers. They has to use something for part numbers

Look at characteristics of that 103 part between TDK and Panasonic - they are different.

But given your use here - just pick the lowest one in the range and go with that. Just pick one that can handle required current.

[matura713]

ok, i see, thanks... i will use first just wires to restore the traces and see if the board still works, i hope nothing more is broken.