bluedraco Posted May 8, 2005 Share Posted May 8, 2005 hey guys haven't posted on the klipsch forum in many years! i woke up this morning to a hissing noise coming out of my right front speaker on my promedia 4.1s... i have only used them for probably 50 hours of actual playing music/games because 99% of the time over the last whatever many years (4 or 5 or something) i have just had them "off" and using headphones off the headphone jack... anyway, so i woke up to this hissing/static type sound and had to unplug the speaker cable to stop it...it has me worried because i've barely used the things and haven't really touched them (been in the same spot gathering a bit of dust) for quite awhile... now i have done the following: 1) turn the "preamp" (front left speaker controller) both on (green) and off (red) several times...the noise stays... 2) reset the sub amp (main power) several times, leaving it off for a bit...the noise stays... 3) unplugged the connection between the preamp and the sub and the noise stays... 4) plugged different speakers and different cables into the front right output on the back of the sub and the noise is still there... this all tells me that something inside the sub amp is wrong with the front right channel... now, does anybody else have any idea as to what this could be? has anybody experienced this before? is it a known problem or something? i'm pretty good with electronics and fixing things...i've done a lot of soldering, i have installed many car stereos (with amps, subs, head units, etc) and many home theatre systems before, so i see myself as capable with fixing these sorts of things...i just need any ideas/help if possible to save me time! i'm a bit frustrated though...i mean, i have barely used these speakers and never overdriven them and now this happens? i'm thinking i'm just going to open up the sub (with the power unplugged obviously) and have a look at the amp and see if there are maybe some dry solder joints or a blown cap or something...but i'll wait for a response or two first! thanks blue Quote Link to comment Share on other sites More sharing options...
craftsman Posted May 8, 2005 Share Posted May 8, 2005 By all means open them up. Once you open them up, you will find 8 printed circuit boards - 5 of them will be identical. Those 5 are the 5 amp boards for the speakers. On each amp board, you will find a jumper which will control which channel the amp will be responsible for. Just change the jumper and see if the noise follows the channel. If it does, then the amp boards are fine. And the op-amps on the long thin board many need replacement. If you take a little more time and look at a couple of the other boards while you are in there, you will find that at least 2 or 3 resistors may need to be replaced. They will be heavily discoloured due to heat and you might see some burn marks on the printed circuit board. I've got a couple of postings with values of 2 of them but the 3rd one I can't seem to get a good reading on. If you can help, let me know. Quote Link to comment Share on other sites More sharing options...
bluedraco Posted May 8, 2005 Author Share Posted May 8, 2005 ok, i have opened it up... there are 3 boards that i see: 1) the long thin board at the bottom which houses the main power, the speaker connectors for the back of the sub (where i plug each of the satelite speaker into), etc... 2) the medium sized board in the middle that has the "danger high voltage" cap (?), a coil, and a few more big black caps... 3) the biggest board that has 5 indentical colums with "front left", "front right", "rear left", "rear right" and "sub" positive and negative paired connectors... now, i've had a look on all the boards and can't seem to find any bad solder connections nor any blown caps, resisters, diodes, etc... on board number 3 i did swap the front left and front right speaker connectors (the pair of them) with each other and then tried connecting my speakers back up...when i did this the hissing/static sound came out of the front left speaker on the back of the unit instead of the right...this tells me that the problem is somewhere in board number 3 (possibly the front right speaker colum) or BACKWARDS in the circuit...is my thinking correct? what should i do next? is board number 3 definitely the culprit? or is there something else in the circuit BEFORE those connectors on another board (board 3?) that might have something wrong? i really don't know what i should do...should i just replace the resistors in board number 3 in the front right speaker column just for the sake of it? Quote Link to comment Share on other sites More sharing options...
craftsman Posted May 8, 2005 Share Posted May 8, 2005 Okay, just to verify that you have the same set-up as I do, can you check the following: On the long thin board with the speaker connectors, does it have the following number on it: 630043 Rev 4 (located in the middle of the underside (non-component side) of the printed circuit board. On the 5 columns, each of the 5 columns are identical - they are connected via a grey ribbon cable, with power being jumpered from one column to the next, and each board is labeled with 650017 Rev 5 near the speaker wires. In addition, they are 5 independent printed circuit boards connected to the metal plate via a couple of screws. On the medium size board (with the high voltage warning) is really two different boards mounted on the metal back panel. The one with the high voltage warning is labelled - 640014 Rev 6 (middle of the undersize again). The other board is labelled 610036 Rev 6. Do these part numbers and descriptions match yours? Quote Link to comment Share on other sites More sharing options...
bluedraco Posted May 9, 2005 Author Share Posted May 9, 2005 the long thin board has "indigo HC BASH - 6300XX Rev. 1" written on it... the board with the "danger high voltage" and coil on it is definitely ONE board and has "640023 Rev 1" written on it... the board that has the 5 identical colums on it is definitely one single big board as well...i have looked very closely on both sides of it and can't find a model or rev number on it anywhere...it is indeed connected with a grey ribbon cable to the long thin board... edit - oh yeah, and just so you know, i live in australia and own the "230v" version! edit 2 - another thing: i have checked all the resistors, caps, diodes and connections and can't find anything wrong...all caps are good (no bulges or leaks), all resistors look like new, all diodes seem fine, all connections seem solid... edit 3 - also, regarding the (single) board with the 5 identical colums on it, i would like to tell you that there are no jumpers on it to select which channel or whatever they control...it would seem from this and other things that this unit is very different to the one you have and the ones you have come across before...maybe because this is an australian version (230v) or maybe becaue it's a totally different revision!!! Quote Link to comment Share on other sites More sharing options...
craftsman Posted May 9, 2005 Share Posted May 9, 2005 Chances are that it is a 230 V version... However, there are a couple points of advise: 1. From the sounds of it, one channel has a definite problem. Chances are that it is either an Op-Amp or one of the transistors driving the actual speaker. 2. From all of the reading I have done on audio boards, capacitors - especially electrolytic ones - have a tendency to fail. They might not have any physical defects to show for the failure. Check the ones that are close to a heat source - heat tends to damage capacitors. Quote Link to comment Share on other sites More sharing options...
bluedraco Posted May 9, 2005 Author Share Posted May 9, 2005 as i have clearly said, it IS the 230v version...no "chances" about it.. 1. i know that, how do i go about fixing it? 2. i have looked over and over and over all the capacitors and can't see anything physically wrong with them...not to say that there isn't something wrong but it sort of makes it different to fix when i don't really know what ones *might* or *might not* be damaged... i'm thinking that if i can't fix it (looks that way because i don't actually know what exactly is wrong) then: 1) i will take it to an electronics repair shop and see what they have to say (i don't want to spend much money on it, so they might or might not know what is wrong)... if they can't fix it then: 2) i will just swap the cables around internally and use it as a 2.1 system...(i'll just swap the wires for the faulty front right channel with say the rear right and then just use it like that, won't be any difference i'm sure)... it *really* is pathetic that a unit that was hardly used, never abused and cost me $650 australian starts playing up like this...i don't accept the fact that this unit is a few years old...i have a lot to do with speaker/electronics/pc gear, etc and this sort of thing should NEVER happen in any mid-high range gear...NEVER... klipsch denied from the word go that their promedia series had flaws and they still won't admit it to this day that they didn't design them properly... anyway, suffice to say, i will never touch a klipsch product again in my life...and considering i install home theatres for people all the time and recommend products for them to buy, well, klipsch will certainly lose some business (not that klipsch gives a sh*t about customers)...they are just in it to make money... anyway, i won't bother trying to seek help here any more...it's a waste of my time and i'm obviously getting no where...i'm better off seeking help from proper professional electronics experts since klipsch doesn't want to make any effort to help me despite it being their pathetic build quality from a product which cost NEARLY twice the price of something else i could have bought instead... Quote Link to comment Share on other sites More sharing options...
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