Have an old Klipsch 4.1 speaker system? Did it die? I bet you can fix it!

Discussion in 'Computer Audio' started by TOOL1075, Aug 8, 2008.

  1. IM0001

    IM0001 n00bie

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    No so far the components have been left on and I am just using the probes as best I can so far.

    I will probably replace R12 next and try again, but how would I test the bridge rectifier next if need be? (I suppose I can also youtube it so yea..)

    Just need to find the time to work on this.
     
  2. titan97

    titan97 Limp Gawd

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    Does your meter have a diode setting? Use that setting and check each pair of legs, forward and reverse. I believe that this rectifier has 4 leads, so that would mean you would be doing 12 tests. You should get a voltage reading in one direction (~3.7V if I recall) and a zero or "closed" in the opposite direction
     
  3. IM0001

    IM0001 n00bie

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    Here is a link to some pics of my subs insides.

    http://1drv.ms/1vo8Dah

    Is there a chance you can point out what I should be testing as the only thing near the copper coil that looks like a rectifier from what ive found is that little rectangle next to it that only has 2 leads.
     
  4. titan97

    titan97 Limp Gawd

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    In your first photo, in the lower right corner, where the power comes into the system, and near the fuse, is a tall black rectangle with 4 leads. It should have a hole punched through the middle and a corner clipped off.
     
  5. IM0001

    IM0001 n00bie

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    Got it, you can see it in the 2nd photo. Will take a look and see what I find.
     
  6. IM0001

    IM0001 n00bie

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    OK here are the results from my test tonight....

    As it sits in my picture. Starting from the bottom with the black probe and testing the other three with the red. This is done from the ends on the board.

    With no contact my MM reads 1.

    1 - 532
    2 - 621
    3 - 616

    1 - 609
    2 - 1
    4 - 1

    1- 620
    3 - 1
    4 - 1

    2 - 1
    3 - 1
    4 - 1

    So I'm guessing something is off since none of that seems to add up to 3.7v or am I just way out of practice from my old electronics classes?
     
  7. titan97

    titan97 Limp Gawd

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    Did you remove the rectifier from the board before testing? This is required for this type of component.

    Also, what setting did you use on your MM? The numbers you mentioned don't make much sense to me.
     
  8. IM0001

    IM0001 n00bie

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    There is only 1 setting for Diode on my MM. I would assume it is .### from readings I see others get testing on the Tubes.

    Ok removed from the board, I get normal readings from + to AC and - to AC as it should be and around the 620 mark, however is the test between + and - Worth anything? It gives me a reading in the high 800-900's both ways.

    May just replace the part either way since its out.
     
  9. titan97

    titan97 Limp Gawd

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    It sounds like your bridge rectifier is working, but I do have one concern. Your MM is measuring the voltage drop (in mV) in the forward diode direction. Typically, this should be around 700mV, but the 600mV numbers that you are seeing seem ok. However, based upon the schematic of a bridge rectifier, your measurement from 1-4 should be double the individual measurement, since the 1-4 connection goes through 2 diodes in series. You should be seeing around 1400 (2 x 700mV) for a typical rectifier or around 1200 (2 x 600mV) for your specific component. You show only 500mV.

    Could you test that connection again? Also, what happens if you reverse the leads?

    If you are going to replace it, I would look at the thompdale website found further up in this thread and order the problematic resistors too.
     
  10. IM0001

    IM0001 n00bie

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    Ordered a new Rectifier just to be safe, may I ask what are the problematic Resisters besides the R26 and R12? Already replaced R26 and R12 keeps reading proper readings even though it looks toasty. All the other resistors I can reach so far all seem to check out and look like new. Heck except for the R26/R12 guys, everything else inside this thing looks new still. Caps all look good too and I would have expected at least a few of those to go by now.
     
  11. titan97

    titan97 Limp Gawd

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    Without looking at the model-specific thompdale website, I can't say. I'd still replace the R12 and R26 resistors, as their values can change when heated up and under load. If you read the post by Evil Scooter, you will see that he replaced these two units and his buzz went away.
     
  12. IM0001

    IM0001 n00bie

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    Replaced the Rectifier to no avail. Dammit. I need to replace that R12 but I can't seem to find an exact match. About to take this thing to a local shop...
     
  13. titan97

    titan97 Limp Gawd

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    I found all of my parts at Digikey. You can use a higher wattage resistor. I don't have my receipt on me, or I'd tell you what I bought.
     
  14. IM0001

    IM0001 n00bie

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    Got an R12 from Digikey and Success!

    However I think I ordered one too small. The one I got was a 2W and it looks like the one that was in the system was a 3W. It works but I assume its a ticking time bomb before it burns out and should swap it for a 3W or higher.

    On another note, the original R12 works fine, but the solder hole on the edge completely up and disappeared. The torching the original R12 did to the circuit board completely toasted the hole and surface of the board. The coper trace going from the Diode next to it to the hole was chared and when I tried to at least expose some of it to solder to, it also looked too chard and thin to make a good connection.

    In a pinch I soldered a piece of wire I use on other projects between the diode and the hole and it seems to work fine, however I do worry its long term reliability. I believe I need to replace that resister sooner rather than later to be safe, but is there any better way to repair a trace, or is my wire solution the best there is?

    Also is the heat going to be the same if I get a 3W or something bigger?
     
  15. titan97

    titan97 Limp Gawd

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    Typically, the louder and longer you play the sound, the more power that will go through that resistor. 3W was already at the minimum of the limit, so a 2W resistor is going to fail sooner. I would look into getting a bigger resistor. You can either get one single larger resistor of the same resistance, or get two smaller resistors of double the resistance and pair them up in parallel. Either way, you will want to replace that 2W unit.

    Ex: If the original R12 is a 500 ohm, 3W resistor, you could replace it with either:

    1) a single 500 ohm, 4W (or higher) resistor, or
    2) 2 x 1000 ohm, 2W (or higher) resistors, wired in parallel

    Also note that the wire gauge of the resistors gets larger along with the wattage rating, so a 4W or 5W resistor wire may not fit into the same mounting hole as the original 3W resistor.

    Regarding the trace problem, this isn't a huge deal. You will see that the thompdale website mentions this same issue and they recommend you solder one lead of the resistor directly to the diode pad.
     
  16. IM0001

    IM0001 n00bie

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    The stocker was still good by the readings I get off it. The only reason it appeared to fail was the solder point cooking off lol. So I will pick up another 3W one to replace this 2W and see if I can solder the lead bent directly to the diode. Don't know how I didn't think of that but I'm happy either way that my system is back in action. Thanks for the help.

    Also R12 is a 680ohm 3W on this board in case anyone was looking.
     
  17. ajmi982

    ajmi982 n00bie

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    Hi Guys, so here goes nothing... I know this is a really old thread but i see it still gets some love given how thorough it is for the 4.1 system.

    Unfortunately, I have the old (individual satilites with plugs, sub with on/off switch) of the ProMedia 2.1.

    I have posted on Reddit for support and was hoping this forum could help me out as I'm struggling to identify what is going on.

    Here is the Reddit post along with photos:

    I have an original (well older version) Klipsch ProMedia 2.1. The left and right channels work perfectly. Really loud and clear. The subwoofer is a different story. I can have the sub control at any volume level but nothing is being outputted.

    I took it apart this morning but didn't see anything obviously blown. Granted I'm not an electrical engineer do don't really know what to look for besides blown capacitors or fuses.

    I'll add some photos later and I'll also hook the driver up to another sound system to see if it's just the driver. If do that would be a cheap and easy fix. If it's the amp I have no clue where to start.

    Update: images added. Also tested driver in another system and it works fine so unfortunately it seems to be a problem with the amp. All fuses look good.
    http://imgur.com/owdnLGp
    http://imgur.com/Hc9tBCv
    http://imgur.com/qvcpvxs
    http://imgur.com/WSe46pL
    http://imgur.com/x8tDv7a
    http://imgur.com/dfDy5o8

    Did a quick review and noticed that I also had scorched and broken zip ties. I guess something blew up in the amp :(. I'll have to look a lot closer.
    Adding some more photos that might help...
    http://imgur.com/vNlF1uv
    http://imgur.com/jnRDiSu
    http://imgur.com/yfGdeXV
    http://imgur.com/WX1783G
    http://imgur.com/BBshMIr
     
  18. titan97

    titan97 Limp Gawd

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  19. ajmi982

    ajmi982 n00bie

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    yes that is the unit i have. hate to be such a noob with this stuff but can you be a bit more specific? Do i do this with the power turned on? am i going to V DC or V AC on the multimeter?
     
  20. ajmi982

    ajmi982 n00bie

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    is there suppose to be a relay at J104? I just have an open space, the back of the board shows solder but the front there is no little silver piece of metal.

    http://imgur.com/hesPORE
     
  21. titan97

    titan97 Limp Gawd

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    No, that is supposed to be a jumper (a piece of wire), but these types of components are often not installed because they are not needed.
     
  22. titan97

    titan97 Limp Gawd

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    I think this side of the board is after the rectifier ,so set your multimeter to VDC. If that doesn't show anything set your multimeter to VAC and check it again. It won't hurt anything.
     
  23. ajmi982

    ajmi982 n00bie

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    Thanks guys. So it should be plugged in for me to test these voltage numbers correct? Also sucks about that one spot was hoping for an easy fix. I think the whole board should probably be replaced. It's so scorched compared to the others.
     
  24. titan97

    titan97 Limp Gawd

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    Yes, plug it in to do the voltage checks.
     
  25. gwsjr425

    gwsjr425 n00bie

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    Hi, I have a set of 4.1 that I've owned for nearly 15 years or there about....I got them when they first came out. About 5 years ago I lost the rear speakers. For a temp fix I plugged my rears into the front and turned down the surround. Eventually the sub went and am now just getting around to fixing them.

    Before addressing the R12 and R26, i dug out the set up that I had packed away and plugged everything in. I got nothing from the sub and the speakers where all working but hardly any sound was coming out.

    I replaced the r12 and r26 resistors and now its alive again but the rear speakers are still not working at all which is confusing as they produced minimal sound before I swapped out the r12 and r26.

    Any ideas?
     
  26. titan97

    titan97 Limp Gawd

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    More than likely, the pot for the surround channels is bad or dirty. Since you are not getting sound out of both units, this points to a component that is common to both units. The pots are known to be problematic, so I would try to clean them with electronics cleaner.

    Have you tried swapping the quiet speaker towers with the working ones to verify that the speakers themselves are working?

    Have you tried swapping the audio jacks on your PC to verify that the rear channels are turned on and working within the OS and on the PC hardware?
     
  27. gwsjr425

    gwsjr425 n00bie

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    Yes, once I got the sub back up I attached all the satellites to the FR and FL ports and all of them work. This is essentially what I was doing when the Rears first went out years ago. That is...until I lost the sub.

    I hooked everything up again this evening with the amp board out of the sub and switched the speaker jumpers around. The Rear banks is not putting anything out. I get continuity from the black and red plugs to the jack on the back panel so the problem isn't between the board and jacks.

    I visually inspected the banks of components in rows 300 and 400 and they all look good. I'm not all that adapt at reading schematics so I'm not sure how to back track the power flowing into those two banks of components.

    I'll try cleaning the pod.
     
  28. gwsjr425

    gwsjr425 n00bie

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    Hello,
    OK, I opened up the pod and visually inspected the components. All of them seemed to be alright as I have noticed somebody had an issue with one of the 8 prong components. However, when I flipped over the board, there where 4 orange components on the back and one of them had solder that had bled over to an adjacent prong as shown by the yellow arrow in the image linked here. None of the other orange components do this.

    http://s1212.photobucket.com/user/gs425/media/DSCN0235_zpsp7qfpo5g.jpg.html?sort=3&o=0

    Could this be it?
     
  29. titan97

    titan97 Limp Gawd

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    It is certainly possible. I would resolder it and break that connection.

    Regarding the pots, there won't be any visible issue. I would still try to clean them with some electronics cleaner.

    One thing you can easily try: Switch around the connectors on the amplifier board, and see if the problem follows the swap. So, if you know that the front channels work, then swap those leads to the rear amplifier connections.

    Have you tried swapping the audio plugs at your PC? In my 4.1 system, I think they are green and orange?
     
  30. gwsjr425

    gwsjr425 n00bie

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    After a visual inspection of the components and before I cleaned the pod, I reassembled it and fired it up. I now have nothing coming out of any speaker except static when before I at least had the front speakers and the sub working. Would this indicate that there is a loose connection somewhere in the pod or with the wiring coming in and out of the pod?
     
  31. gwsjr425

    gwsjr425 n00bie

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    FWIW, I do have power going to the pod. The light is red when off and green when on.
     
  32. titan97

    titan97 Limp Gawd

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    Does the volume of the static change if you turn the knobs up and down?
     
  33. gwsjr425

    gwsjr425 n00bie

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    I think I"m good. Last night I broke down the amp to get to the r27 to replace it and took apart the pod again to clean it. When I got it all assembled again, I had life...no static or hum.

    I think my rear speaker issue is my computer. I have a Dell Precision M4600 laptop. Its a killer system for my CAD work but its got a shitty card in it. I only have a headphone out jack to use so I have an 2 into 1 adapter hooked up to it. The only option I have in the sound config list is "stereo"

    I have an old Win Vista desktop system packed away Im going to pull to see if that has a better card in it I can test the Promedia's in 4.1

    I'll keep the forum posted. Thanks for your help.
     
  34. titan97

    titan97 Limp Gawd

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    Cool. Good to hear. Do you know what caused the system to start working?
     
  35. gwsjr425

    gwsjr425 n00bie

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    My guess is a loose connection from when I first took it apart. After I broke it down the second time to get to the r27, I may have not hooked everything back the proper way. The red power wire that goes to the amp board slipped off its post very easily...almost with no resistance. That most likely wasn't seated properly.

    On another note, the 4.1's have a two prong connector that is supposed to plug into the sound card. The light green one goes into the audio out or the "headphone" jack, where's the purple one supposed to plug into. As I mentioned, right now i have both plugged into a 2 into 1 adapter and that prong is in the headphone jack.
     
  36. gwsjr425

    gwsjr425 n00bie

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    update: After performing three of the fixes here (r12, r26, r27) my Promedia 4.1's are up and running again. I wasn't getting rear speakers but that turned out to be just my config in my laptop. I hooked the speakers to a desktop with a good sound card and was able to config the speakers properly and all works the day it came out of the box!

    I would not have been able to fix these without the this forum and would have most likely thrown the system away. Here's hoping for another 13 years of use!!
     
  37. titan97

    titan97 Limp Gawd

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    That is certainly good news. I think for your next project, look at refoaming the subwoofer speakers. The foam surrounds on my units fell apart last year and I paid around $10 to purchase new foam. With the shot foam, the speakers would rattle like crazy.
     
  38. skynet3020

    skynet3020 n00bie

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    Sorry for the necro-post but wow, this is a great resource. I'm grateful that you are sharing this information. I have one of the 4.1 ProMedia sets - good speakers that have lasted me a long time. Like others in this thread mentioned, I had the foam surrounds rot out on the sub and the drivers started rattling. The surrounds were fairly easy to replace and the sub still sounds great after 4 years.

    Now the set set is starting to behave strangely - it still has power (LED on the control pod) but sometimes the speakers don't produce any sound, or they produce a high-pitched squealing noise without any input. It seemed to be worse in the summer when the unit was hot and especially after not being used for a while, and has been getting worse slowly for the past year or so. I even unplugged the DIN connector while it was squealing and it kept doing it - strange stuff. This all probably points to some heat-related issue in the amp.

    Anyway, I opened it up and despite being 16 years old it looked pretty good inside. R12 on the digital converter and R26 on the dc-dc converter were cooked of course - R26 is all cracked and nasty looking. I measured (while still on the board) 640 ohms across R12, and 52k on R26 - not terrible values but a bit off - I'll try replacing those. The color bands are basically unreadable - it would be hard to figure out the right values without this site.. Everything else looked fine as far as I could tell but I didn't measure anything else.

    Even if I do fix the problem, it may take a year of trouble-free use - or at least the next summer - before I can be sure.
     
  39. titan97

    titan97 Limp Gawd

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    Gotta love the HardOCP. We are still here, years later, trying to help each other out.
     
  40. TOOL1075

    TOOL1075 Gawd

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    Hey everyone! I made this thread back in the day to try to help folks out. I haven't been back to this site in a while - good to see people are still using this!!!!


    Wanted to update everyone. I am still using my speakers. I use them connected to a laptop docking station in my home study. Last night, while listening to some bass heavy music, one of the woofers failed. The foam surround literally crumbled.

    I just got off the phone with Klipsch. Although they don't make the 4.1 system anymore - they apparently make the 2.1 system, and the woofer drivers used in the 2.1 are the same as those used in the 4.1. So I ordered two of them! They should be in my hands Thursday. I'll replace both drivers in the subwoofer.

    The total cost, shipped was $49. Not bad for a 17 year old system driver replacement. The guy told me they have upgraded/changed the driver surround material so the new ones should give more use. If I get another 17 years, I'll be happy.

    I'll try to post here more.... HardOCP was the shit back in the day.
     
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