Troubleshooting Harman Kardon TS-14 Subwoofer

[Jdog420]

Found this cool site while looking for some answers on my sub. Started off intermittent, switching it on and after a minute of thumpage, going into standby. Now when I switch it on, it is trying to turn on but it cycles back into standby, continually. I took it apart and damage wise it looks to be this. Apparently it overheated and melted the coating, but am somewhat newbage and am unable to figure out what the specs are to this, resistor?

[Dgtech]

Re: Troubleshooting Harman Kardon TS-14 Subwoofer

From what I can make out (pics too small), It's an inductor. They rarely go bad and will work with the melted outer shell. What makes these hot is whenever there is too much current going thru them. I can't make it out but it looks to be a bad cap or two near it. These will need to be replaced but it would be nice to see larger pictures of the whole board to make a proper determination. Use "Manage Attatchments" just like you did but larger pictures. Not too large though.

[Jdog420]

Re: Troubleshooting Harman Kardon TS-14 Subwoofer

Cool, working on the bigger picture. I was disappointed myself when I clicked on it.

[Jdog420]

Re: Troubleshooting Harman Kardon TS-14 Subwoofer

Resized photos in.

[seanc]

Re: Troubleshooting Harman Kardon TS-14 Subwoofer

Yes there are two bad caps there.

[lti]

Re: Troubleshooting Harman Kardon TS-14 Subwoofer

They leaked all over the board too. You will need to clean the residue off of the board.
Harman Kardon likes to use crappy caps and place them in very warm locations. I found that out while repairing a set of Harman Kardon computer speakers.

[Longbow]

Re: Troubleshooting Harman Kardon TS-14 Subwoofer

I'd like to see any other boards that are part of the subwoofer also. The main focus at the moment is to remove the inductor and the 2 caps and start cleaning the pc board to remove the conductive electrolyte that spilled. Also look carefully at the bottom of the board where these parts are soldered, as the fluid might have done damage underneath as well.

I'm wondering if the board we see in the photo is a power supply? The inductor is a high current high value (ferrite core) part, connected to a NP cap. Those parts might actually be part of the subwoofer's crossover/low pass filter for the audio. Let us know the results after cleaning and replacing the caps.

[Jdog420]

Re: Troubleshooting Harman Kardon TS-14 Subwoofer

I was gonna take it to the local electronics guy, but appears he isn't open anymore or moved. Looking at irons ( don't have any tools) and replacement caps right now. I'm gonna take the boards apart and post some more pics tomorrow.

[Longbow]

Re: Troubleshooting Harman Kardon TS-14 Subwoofer

This is something that YOU can fix! All you need is an old toothbrush, a soldering iron and some alcohol or lacquer thinner to clean the board. Caps can be ordered from Digikey, Mouser, Newark, etc for a few bucks. Here's your chance to be a hero!

[Jdog420]

Re: Troubleshooting Harman Kardon TS-14 Subwoofer

Thanks for the push Longbow, I usually do surprise myself when I tackle something. I have a habit of talking myself out of things, but once I get into them, turns out they aren't as bad as I perceive them to be. I did take go to a vocational Industrial Electrical Maintenance program, that lightly touched on solid state electronics. However not as in depth as I would have hoped it to been. Looking at this makes me want to go to an actually electronics program. Here are some picks of the rest of the boards. Does they look like quality workmanship to you guys?(made in China, which you guys probably already knew)

[lti]

Re: Troubleshooting Harman Kardon TS-14 Subwoofer

Those boards don't look bad. That is typical Harman Kardon quality.

If the amp runs hot, a full recap might be needed. In the computer speakers I mentioned above, almost every cap was bad.

[Longbow]

Re: Troubleshooting Harman Kardon TS-14 Subwoofer

If we are talking subwoofers with internal amplifiers, it is absolutely certain that the electronics will run hot. The boards are mounted inside the cabinet along with lots of fiberglass insulation (for audio purposes). But that doesn't mean that every part is in immanent danger of failure. Jdog, get yourself a soldering iron and some solder wick and a few supplies. The knowledge and experience I've seen presented on this forum is far more than you'll ever get at the tech school. I'm very big on hands-on. Remember, if it is already broken, you can't do much worse trying to fix it!

[Jdog420]

Re: Troubleshooting Harman Kardon TS-14 Subwoofer

Good point Longbow. I have been checking out some amplifier circuits on buildingGadgets.com, and figure I want to get into it as a hobby. As I play guitar, and wouldn't mind being able to tweak some things here and there or make a little amp. I'm looking at irons, have been going through the Test Equipment Usage, Techniques, and Reviews and gonna make a decision soon, very soon. Not gonna buy a cheapie, but can't go high end. No Bass = Bad

[hardwareguy]

Re: Troubleshooting Harman Kardon TS-14 Subwoofer

Want a cheap, reasonably well behaved soldering station....look at the Weller WLC 100. Its a simple unit with coarse thermal control but it works and is available for around $40 USD. I use one and once you get a feel for what number on the dial corresponds to what size joint you want to rework, its a good unit.

It comes with a small chisel tip, add on the fine conical tip for smaller circuitry. Tips are of good quality, WAY better than the tips you find on cheap "fire stick" type irons. I actually am still on my first tip 6 months in, with an old Radio Shack or ECG iron, I'd have gone through at least 3 tips due to their poor coatings.

If you have more money, step up to the WESD51....that's about the cheapest thing that I'd call a "real" soldering station. Buy one of these or a WD1 if you get serious about electronics. See Hakko's stations as well, they are comparable.

As for multimeters....you CAN NOT get a good, safe meter for under $20 new....I've tried. All of them came with terrible leads and questionable components. Don't skimp too much here....My multimeter has literally saved my life a couple of times. (Test before you touch...and test again!) Excellent units with good reliability and safety features can be found for $35-50, good True RMS units can be found for about $100 new. If buying used, dont get one that's too old....if it lacks an IEC 61010 -1 classification (Category rating), its too old for my tastes as it may or may not have modern safety features. For electronics, you want at least a Cat II unit.

[kaboom]

Re: Troubleshooting Harman Kardon TS-14 Subwoofer

As for multimeters....you CAN NOT get a good, safe meter for under $20 new....I've tried. All of them came with terrible leads and questionable components. Don't skimp too much here....My multimeter has literally saved my life a couple of times. (Test before you touch...and test again!) Excellent units with good reliability and safety features can be found for $35-50, good True RMS units can be found for about $100 new. If buying used, dont get one that's too old....if it lacks an IEC 61010 -1 classification (Category rating), its too old for my tastes as it may or may not have modern safety features. For electronics, you want at least a Cat II unit.

And absolutely none of those "830" meters, or their clones (of clones).

[Jdog420]

Re: Troubleshooting Harman Kardon TS-14 Subwoofer

Thanx guys, I think I have narrowed it down to that Weller WLC 100 and the Goot PX-201. I'd go with the Weller WESD51 If I was working (been holding out to see if this one i got on a line goes through). But yea as far as the DMM, I so want a Fluke. Been checking Craigslist and ebay, but hold their value quite well. Ive used them (company supplied) and they are awesome. Funny you mentioned the under $20 category. I bought some POS from Marcs for like 4 bucks just to check really low voltages. One day i felt the need to check an 110v outlet, and blew the leads off. MUhahaha!!

[Th3_uN1Qu3]

Re: Troubleshooting Harman Kardon TS-14 Subwoofer

The 830s are (reasonably) safe if you use proper leads with them. I own three... But for a more serious meter, if a Fluke seems too expensive i recommend the Uni-T UT60E. I have little to complain about it, and where i do have complaints it's minor things.

[kaboom]

Re: Troubleshooting Harman Kardon TS-14 Subwoofer

Uni-T UT60E.

MCM's 72-7740 is the non-TRMS w/o RS232 version of that. 72-7735 has RS-232, but is not TRMS.

[tom66]

Re: Troubleshooting Harman Kardon TS-14 Subwoofer

On the subject of multimeters I use a BK 2709B and it works well but will set you back nearly $100. Very nice inside (good safety features), true RMS and the first auto and manual ranging capacitance test I have seen on a multimeter to date!

[Jdog420]

Re: Troubleshooting Harman Kardon TS-14 Subwoofer

So got some things to gear up for the attempted fix. Bought a Hakko FX-888 and well what are supposed to be rubycons (can any of you spot fakes?). However I think I had a fail in the caps department, the temp is only rated 85C while the OEM are 105C. Maybe not a big deal, but the OEM are noticeably larger.