Bad caps or inductors on Klipsch ipod speaker unit

[Welchs101]

Re: Bad caps or inductors on Klipsch ipod speaker unit

I thought i would show what the board looks like now after i cleaned it up and soldered in the new capacitors.

[sofTest]

Re: Bad caps or inductors on Klipsch ipod speaker unit

Did you check that the new capacitors (Panasonic NHG?) have same or better ESR/impedance and ripple as the old ones?

Also, you should test the capacitor with the yellow mark on and remove the rest of the glue.

[Welchs101]

Re: Bad caps or inductors on Klipsch ipod speaker unit

I actually did not check the ESR rating of the new caps. They were caps i had left over from some thing. But they were new. Still, i would not think that even if i had the ESR wrong that all 4 inductors and both caps would be sooo Hot. I could be wrong but that is what i was thinking.

I will check the other capacitor with the yellow on it......but i did touch it when the unit was operating and it was not hot.

thanks for the input.

[sofTest]

Re: Bad caps or inductors on Klipsch ipod speaker unit

If you put in capacitors with to low ripple tolerance for the condition they operate under, the capacitors heat up. That again reduce their lifespan. Unless you have good reason not to, one should replace with same or better specified capacitors.

That the yellow marked capacitor don't get hot, don't mean it's good. It could be high ESR, shorted or open. It's difficult to tell from the pictures, but it doesn't look like a capacitor from the "good list".

What tools for testing do you have? If you have an ESR-meter, test the other capacitors. If you have a DMM, test the diodes, resistors etc. Also check the voltage(s) that comes into the board.

[Radio Fox]

Re: Bad caps or inductors on Klipsch ipod speaker unit

Is it possible to power up the unit while measuring the voltage across the 2 new capacitors?

I can understand the inductors getting hot if there is a short circuit somewhere causing excess current through them, but what is causing the capacitors to get so hot so quickly? Reverse polarity, over voltage or AC across it's pins is all I can think of.

[Radio Fox]

Re: Bad caps or inductors on Klipsch ipod speaker unit

btw...when you say that you turned it on & waited 5 minutes, was the amplifier actually working during that time?

[smeezekitty]

Re: Bad caps or inductors on Klipsch ipod speaker unit

How many volts across the capactors? and the inductors?

Also, you should test the capacitor with the yellow mark on and remove the rest of the glue.

Good point as some manufacturers use a mark on top to signify bad components (Rare but i have seen it).

[hardwareguy]

Re: Bad caps or inductors on Klipsch ipod speaker unit

Is this part of the output stage of a Class D amplifier? If so, the replacement caps MUST be low ESR.

In general, for any type of switching power supply or switching amplifier, the output caps need to be low ESR or excessive heating will occur in the caps.

Check for shorts in other parts of the circuit and verify that the caps are installed properly and of the same or greater voltage as the originals.

Cap heating is abnormal but it *might* be normal for the inductors. Some systems (newer laptops and the Playstation 3 come to mind) actually heatsink the inductors!

[hardwareguy]

Re: Bad caps or inductors on Klipsch ipod speaker unit

Looking at the pics closely I can see that this is indeed a Class D amp!

The small quad flat pack chip from Texas Instruments is the amp! Datasheet is here: https://cdn.badcaps-static.com/pdfs/...13b5605905.pdf

Looking at this I'd say those inductors are the output filters leading to the speakers. Current to the speakers passes through this filter. In this application, they shouldn't get warm unless at or near full volume.

Output filter caps are small....the ones you replaced are likely the power supply filters.

Verify this by tracing out the circuit and looking at the datasheet. Understand the circuit and you will make a more educated guess as to what is wrong.....right now I'd look at the power supply circuit.

[hardwareguy]

Re: Bad caps or inductors on Klipsch ipod speaker unit

Show us some high resolution pics of the power supply. Take some measurements to verify that its output is reasonable....and test caps in the power supply as well.

[Welchs101]

Re: Bad caps or inductors on Klipsch ipod speaker unit

I am enclosing a few pics.
1) Is a higher resolution pic of the top half of the board.
2) is a higher resolution pic of the bottom half of the board
3) Representative pic of the bad cap removed.

The replacement cap i used was
http://search.digikey.com/scripts/Dk...ds=565-1544-ND

I did a test today. I dont know if it means anything or not but this is what i did. I Plugged in the power, i attached the IPOD to the front so it was playing a song once power was on, and i attached the cable from the IPOD to the mainboard . What i noticed is that CAP-A in the picture i enclosed..........is what got hot. I turned theunit on and waited a few min.........CAp-A was the only thing hot. I am sure the other cap and inductors would have gotten hot if i let it stay on longer but the other devices did not seem hot after 5 min.....only capA was hot.


The speaker unit only has 1 main board.

Any suggestions on what to measure would be helpful. I am not sure where to measure but if you have suggestions just let me know.

[Welchs101]

Re: Bad caps or inductors on Klipsch ipod speaker unit

One other thing i wanted to mention. The power supply for this unit is included in the power cord i think. The cord has the "box" where i think the transformer and such are located. Hope i made sense?

[Welchs101]

Re: Bad caps or inductors on Klipsch ipod speaker unit

I finally got around to measuring a few voltages.

Voltage coming from power cord (remember i think it has the ac to dc conversion in the box thats on the power cord) measures 15V. I plug power to unit. Turn it on and measure voltage and it measures 15V. Now when i play a song through the unit voltage drops to 7.9 volts...~ 8V. And only capA gets hot. The other caps and inductors dont seem to get hot at least at the 3min mark.

Does this give anyone any ideas as to what to look at or try or anything?

[hardwareguy]

Re: Bad caps or inductors on Klipsch ipod speaker unit

Your link says you bought a 47uF cap...you removed a 470uF. A tiny cap where a 10x bigger one once was installed could overheat due to excessive ripple current.

Perhaps cap A is defective? It appears to be no more than a supply filter cap.

[Welchs101]

Re: Bad caps or inductors on Klipsch ipod speaker unit

Sorry....that was a typo on my part. Both new caps were 470uF/25V. Same as the original.

I guess the new one could be faulty but since they were "new" i did not think of this.

[Welchs101]

Re: Bad caps or inductors on Klipsch ipod speaker unit

The capacitor part number i put into a previous post was the wrong one.....sorry about that my fault.

The cap i put into this unit is shown below:
http://search.digikey.com/scripts/Dk...ords=P13124-ND

Also, i wanted to give you an update on what i know.
For those that dont know i have a ipod speaker system that a friend gave me to look at. When i initially opened the unit up i found that two of the caps were bad. I replaced the caps and when i tried the unit out it worked but the caps were really really hot.

What i have found recently is this:
When i power the unit on, with no ipod actually in the unit, the caps DO NOT get hot. However, when i put an ipod in and play a song (song must be playing) the cap (shown as CAPA in pic) starts to get hot. This is the only device that gets hot initially. Does this tell anyone anything?

Anyone have a suggestion as to how to proceed on diagnosing the unit? I tried calling the company to see if could get a replacement board .........they said no they dont sell those alone.

[Welchs101]

Re: Bad caps or inductors on Klipsch ipod speaker unit

Forgot to mention this in my previous post. The voltage coming out of the power cord is 15V DC. Voltage on the cap when i turn the unit on (no ipod playing song) is also 15V DC. When ipod starts playing song voltage drops to ~ 8V and CAP-A starts to get hot slowly.....its not instantaneous.

[Krankshaft]

Re: Bad caps or inductors on Klipsch ipod speaker unit

Just right off the bat I see a PTC (Princeton Technology Corp) IC in there so my first response is cheap Chinese crap. Which means cheap Chinese caps.

Are those two caps speaker decoupling caps?

A decoupling caps job I believe is to prevent DC from getting to the speakers from the amp speakers are AC devices and DC destroys them. The max ripple current on these Panasonics seems way too low to me and the ESR is probably too high.

Were the original caps low ESR? I know Panasonic well and EB is General Purpose.

When in doubt install low ESR caps they can ALWAYS replace GPs but not the other way around. Panasonic FCs would be good here low ESR and they can work well in hot environments.

The ripple for that EB cap is only 321mah. While the ripple on a comparable FC is 1050mah. Your exceeding the caps ripple current and heating it.

[Krankshaft]

Re: Bad caps or inductors on Klipsch ipod speaker unit

Ironically enough the Chemicon KY cap you put in your previous post would have had the proper ripple .

I wouldn't use KY though I have had them fail on hot running PC graphics cards.

[Welchs101]

Re: Bad caps or inductors on Klipsch ipod speaker unit

I am enclosing a pic from a previous post. This pic is the cap that i took OUT...that was "bad".

I replaced the bad cap with the following cap
http://search.digikey.com/scripts/Dk...ords=P13124-ND

Sounds like i may have put in a cap which was not correct.

Questions:
1-Can someone find the data sheet on the bad cap? I have looked and cant seem to find one.
2-Can someone identify a replacement on digikey or someother site........so i can look at the datasheet and compare the two.

Thanks.