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Component 100 6U? On H340 circuit-board. Capacitor?

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dreamlayers:
I'm almost certain they are capacitors.  Look at the board images.  Components with such markings are labelled CE on the H3x0 and C on the H1x0.  Inductors are labelled L.  The markings on the part also correspond the to the tantalum electrolytic capacitor datasheet I posted.

Regarding it passing current, if it's still connected to the circuit on both sides, the current may be passing via another path.

piscator:
I've never added a picture to a post, but here goes!



http://download.rockbox.org/device-pictures/iriver/h300_front.jpg

In this photo the component is labeled 100 6T  It's the square component to the right of the orange charging jack, about 1" above the DATA port.

To my eyes the board designation appears to be C11

Using my multimeter, this device passes current (the meter buzzes) with the probes touching the solder connections on both sides (North and South)

My meter also buzzes with one probe on either side of 100 6T and the other probe to ground, the metal surrounding the DATA port, for example.

On MisticRiver, Horst stated that if the iRiver's capacitors were hit with to high voltage they would 'turn to solid wire' -- one result being the DAP showing 'connected to USB' when it is not.  That's what my h340 is doing.


Dreamlayer, I am testing the 100 6U while it is connected to the board.  That's what the engineering gent at misticriver suggested. 

Also, thank you for that Rockbox link where I found the picture.  I don't know how to add personal pictures to a post.

It seems I've fried my player!!!!  I was learning so much swapping different hard-drives and now I've screwed the thing up  I love the h340 and they're not easy to come by :( :-[ :'

piscator

P.S.  Dreamlayer/Boris,


--- Quote ---100 is the capacitance in microfarads.  That is the same value as 107 in the more common code, meaning 10 followed by 7 zeros picofarads 6 is the voltage U is a date code...
--- End quote ---

This was very helpful.  My thinking was that the 100 was microfarads, but I didn't understand the 6 to be voltage.  That would concur with the voltages cited by the engineer over at misticriver.

johnp_g:
Hello Piscator,

To my eyes, and without an HG340 to check against, it looks like the component (100 6T) is CE11.

The other SM components of similar appearance and size also have CExx designations so I'd guess they were Electrolytic Capacitors (hence CE).

The banding at one end of the device would indicate the polarity (electrolytic capacitors are sensitive to polarity, with the band being the positive terminal).

If there's a s/c across this component, in BOTH directions (ie with the either lead of the ohm meter attached to either end of the component) and between either terminal and GROUND, this would imply a s/c somewhere to ground.

Electrolytics are either used as decoupling capacitors, between a DC rail and earth to remove AC signals and noise from supply rails, or as coupling capacitors to isolate DC levels between stages, but passing AC signals. If this capacitor is the former then measuring the DC resistance to ground across it will also bring into question every other component (eg other decoupling capacitors) across the same circuit point and ground.

The only way to be sure that this component has failed s/c is to remove it from the board to test it in isolation.

If it's a decoupling cap. and has gone S/C then removing it should allow everything to function normally (near enough).

If you can remove it safely - can you then test across the PCB pads where it came from? If there's still a DC s/c (with the leads connected both ways round) then there's something else to blame.

Be sure to do all the DC resistance checks with the battery removed BTW!


Sometimes, with components this small it's impossible to find the guilty party, especially with no circuit diagram to work with.

God luck

John

yapper:
I agree with John's advice (my previous comment about it possibly being an inductor was based on the lack of a mention of a coloured band, but seeing the picture it's clearly a capacitor).

piscator:
John and Yappy,

I can't thank you enough for your help!

At the same time, I can't say I'm exactly happy to have you confirm my suspicions that I fried this darn thing.  :-[ :o :(

John wrote:


--- Quote ---The banding at one end of the device would indicate the polarity (electrolytic capacitors are sensitive to polarity, with the band being the positive terminal).
--- End quote ---

Yes, this component (100 6U) is banded with the grey band on the side nearest the DATA port.


--- Quote ---If there's a s/c across this component, in BOTH directions (ie with the either lead of the ohm meter attached to either end of the component) and between either terminal and GROUND, this would imply a s/c somewhere to ground.

--- End quote ---


I believe this is what's going on, but I'm going to check it again.  I need to find some needle-thin probes for my ohmeter, It's tight in there!


--- Quote ---Electrolytics are either used as decoupling capacitors, between a DC rail and earth to remove AC signals and noise from supply rails, or as coupling capacitors to isolate DC levels between stages, but passing AC signals. If this capacitor is the former then measuring the DC resistance to ground across it will also bring into question every other component (eg other decoupling capacitors) across the same circuit point and ground.
--- End quote ---


I believe the engineer posting at mistic-river described them as decoupling capacitors.

Testing other capacitors on the board (brown SM caps that are clearly marked) I get continuity (meter buzzes) between ONE side of every capacitor and ground.  I'm don't know if this is 'normal' and/or related to your comment:


--- Quote ---across the same circuit point and ground.
--- End quote ---

I am concerned that there is more damage than I'm able to resolve.  For instance:

Brown (bubbly epoxy? burn marks?) around the base of the DATA port where the metal outer housing is soldered to the board.  These are not severe, but must indicate something.

One of these brown burns is on the right side of the DATA port base (ground?) and extends 'North' to an SM capacitor marked C96.  It looks like someone used a brown marker to draw a straight line up to C96.  C96 itself is not brown. 

I tried to take a picture of this, but my camera is not able to close focus.


--- Quote ---Sometimes, with components this small it's impossible to find the guilty party, especially with no circuit diagram to work with.
--- End quote ---

You're obviously correct on this score!  It's tight in there.  I'll work on this some more and try to verify my tests with a better meter.

It's really a shame, this h340 is absolutely pristine and they're getting harder to come by. 

I did find a h320 on Ebay and snagged it just in case.  It's not as nice as my h340, but maybe I can swap cases or cobble something together.  Sure is a learning experience.

Thanks again for your help.

Sincerely, piscator

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