cbradshw

I HAVE SINCE FIXED THE THE RIGHT CHANNEL PROBLEM. Turns out to have been a corroded copper tracing on the circuit board before the signal goes to the amp card. See more details at my website: http://christopherbradshaw.net/The_Project_Bin/klipsch%20promedia%20subwoofer%20repair%20-%20page%201.html --------------------------------------------------------------------------------------------------

I HAVE SINCE FIXED THE THE RIGHT CHANNEL PROBLEM. Turns out to have been a corroded copper tracing on the circuit board before the signal goes to the amp card. See more details at my website: http://christopherbradshaw.net/The_Project_Bin/klipsch%20promedia%20subwoofer%20repair%20-%20page%201.html -----

I HAVE SINCE FIXED THE THE RIGHT CHANNEL PROBLEM. Turns out to have been a corroded copper tracing on the circuit board before the signal goes to the amp card. See more details at my website: http://christopherbradshaw.net/The_Project_Bin/klipsch%20promedia%20subwoofer%20repair%20-%20page%201.html --

UPDATE: I have been carefully examining schematics and using a volt meter to determine that all proper signs of voltage are appearing at the proper places according to the schematics. I am beginning to suspect that the TL074 component chip is failed. I realized today from the TL074 datasheet that it actually contains 4 independent amps within itself! One for each satellite channels and two for the sub channel. There are two main output transistors on the SP2 card that I may consider investiating for failure as well. I leave these updates for other fellow repair travellers. Namaste, Christopher

I seem to be on the same trail that Valter was on and I agree and respect his perserverance to see the problem solved. My problem is that I lost the right side speaker sound. The wire and speaker are fine as they work perfect on the left side. Upon looking at the schematic for the Input/Output board the componenent listed as part U201 is a integrated circuit (TL074) that operates amplification for all three signal systems, the sub (low frequency) system, and both satellite (high frequency) systems. I have confirmed that all proper voltages are showing up at the correct places and this leads me to consider changing the TL074 for a new one. I am also considering the output transistors Q9 and Q10 on the speaker card for possible failure. If I should find new information I may update in the future. Christopher

I HAVE SINCE FIXED THE THE RIGHT CHANNEL PROBLEM. Turns out to have been a corroded copper tracing on the circuit board before the signal goes to the amp card. See more details at my website: http://christopherbradshaw.net/The_Project_Bin/klipsch%20promedia%20subwoofer%20repair%20-%20page%201.html -------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- Hello again, I purchased a new control pod but that didn't fix a thing so I know that the pod is most likely fine. What I did find is that I have a conflicting set of resistance readings from the two channels. Here are some resistance readings I took: Sub speaker terminals with no wires connected: 5.7 ohms Satellite speakers with the wires attached, tested at the ends of the wires: Left: 5.9 ohms, Right: 6.2 ohms I also decided to compare the output terminals for both channels on the back of the amp box as I have a failing right channel. The odd thing is that when I select different ohm ranges on the multimeter I get a different resistance reading. Also the readings tend to climb upward at a certain rate (like it's walking up(capacitor?)) and then rest at a value. Here are the channels and ohmic ranges: LEFT CHANNEL: Ohm Range 0 - 2,000 => (too high for this setting) Ohm Range 0 - 20,000 => 8,5000 ohms Ohm Range 0 - 200,000 => 55,000 ohms Ohm Range 0 - 2,000,000 => 385,000 ohms RIGHT CHANNEL: Ohm Range 0 - 2,000 => (too high for this setting) Ohm Range 0 - 20,000 => (too high for this setting) Ohm Range 0 - 200,000 => (too high for this setting) Ohm Range 0 - 2,000,000 => Starts at a high realing like 1,600,000 and then climbs out of this top range. There is a issue here. Any ideas where i can start looking? I do have schematics on hand for the circuitry. Christopher

Hello again I thought I would add some follow up issues with my lost channel: Sub speaker terminals with no wires connected: 5.7 ohms Satellite speakers with the wires attached, tested at the ends of the wires: Left: 5.9 ohms, Right: 6.2 ohms I also decided to compare the output terminals for both channels on the back of the amp box as I have a failing right channel. The odd thing is that when I select different ohm ranges on the multimeter I get a different resistance reading. Also the readings tend to climb upward at a certain rate (like it's walking up(capacitor?)) and then rest at a value. Here are the channels and ohmic ranges: LEFT CHANNEL: Ohm Range 0 - 2,000 => (too high for this setting) Ohm Range 0 - 20,000 => 8,5000 ohms Ohm Range 0 - 200,000 => 55,000 ohms Ohm Range 0 - 2,000,000 => 385,000 ohms RIGHT CHANNEL: Ohm Range 0 - 2,000 => (too high for this setting) Ohm Range 0 - 20,000 => (too high for this setting) Ohm Range 0 - 200,000 => (too high for this setting) Ohm Range 0 - 2,000,000 => Starts at a high realing like 1,600,000 and then climbs out of this top range. There is a issue here. Any ideas where i can start looking? I do have schematics on hand for the circuitry. Christopher

I HAVE SINCE FIXED THE THE RIGHT CHANNEL PROBLEM. Turns out to have been a corroded copper tracing on the circuit board before the signal goes to the amp card. See more details at my website: http://christopherbradshaw.net/The_Project_Bin/klipsch%20promedia%20subwoofer%20repair%20-%20page%201.html -------------------------------------------------------------------------------------------------- Hello again and here's the speaker readings I took: Sub speaker terminals with no wires connected: 5.7 ohms Satellite speakers with the wires attached, tested at the ends of the wires: Left: 5.9 ohms, Right: 6.2 ohms Hope this helps! I also decided to compare the output terminals for both channels on the back of the amp box as I have a failing right channel. The odd thing is that when I select different ohm ranges on the multimeter I get a different resistance reading. Also the readings tend to climb upward at a certain rate (like it's walking up(capacitor?)) and then rest at a value. Here are the channels and ohmic ranges: LEFT CHANNEL: Ohm Range 0 - 2,000 => (too high for this setting) Ohm Range 0 - 20,000 => 8,5000 ohms Ohm Range 0 - 200,000 => 55,000 ohms Ohm Range 0 - 2,000,000 => 385,000 ohms RIGHT CHANNEL: Ohm Range 0 - 2,000 => (too high for this setting) Ohm Range 0 - 20,000 => (too high for this setting) Ohm Range 0 - 200,000 => (too high for this setting) Ohm Range 0 - 2,000,000 => Starts at a high realing like 1,600,000 and then climbs out of this top range. There is a issue here. Christopher

Hello Liplesseagle, I've got the 2.1 system and have it limping right now (right channel doesn't work). I'll take a measurement of my sub speaker's resistance and post it here over the weekend. Perhaps tomorrow. I've have to replace the main power transformer on my system after the thermal fuse called it quits after about 9 years. Just hold tight for a little bit. Christopher

I also have the same problem as the ports on this thread, a dead right channel. This was discovered after replacing the main power transformer. I haven't seen any signs of damaged components on the SP2 card and the fuses are fine when tested with an ohm meter. I also checked the speaker and wire over to the other channel and they work fine. I've tried a brand new controller but no change. I noticed in one of the earlier posts with the photo of the burned transistor. I wonder if replacement got the unit working again. I've checked out connectivity of my DIN cable and that seems good. Any progress from anyone? Christopher

I HAVE SINCE FIXED THE THE RIGHT CHANNEL PROBLEM. Turns out to have been a corroded copper tracing on the circuit board before the signal goes to the amp card. See more details at my website: http://christopherbradshaw.net/The_Project_Bin/klipsch%20promedia%20subwoofer%20repair%20-%20page%201.html ---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- Hello all, I too experienced a problem one day when our 2.1 ProMedia system wouldn't turn on. No thump, no green light, no internal relay click, nothing. After careful research and looking at schematics I determined that the main transformer (Transtec) had blown it's internal thermal fuse. I was happy to find this transfomer still available online and ordered one. Put it in last night and horah! The thump, green light and relay click were back! EXCEPT! The right channel is gone. I switched the wire and speaker over to the left side to rule out faulty satellite gear and they are fine. Interesting issue is that when I umplug one of the wire leads from the back of the sub and then poke around with it in the hole I can hear faint crackling from the speaker. This tells me that they is voltage in the line just no signal. So I now have read a lot about people's issues about the internal fuses, the DIN plug, and the control module. I am going to verify that the DIN plug all the way to the interface plug on the control module is o.k. I know that people like Mister Clean will service the DIN plug but before I do that does anyone have further thoughts about the possibilities of the lost right channel? OH! I've made this repair into one of my webpages and I you're interesting in viewing it it's at: http://christopherbradshaw.net/The_Project_Bin/projects.html Cheers to you all, Christopher