Hello everyone! I found this site by looking for some tips on repairing the amplifier for a set of speakers I'm pretty fond of. A while back, someone posted here about a Klipsch Promedia 2.1 system Previous topic that lost audio on the left channel. I have a similar issue, but not quite the same as his, and that thread was never resolved. His actual speakers appeared to be damaged while mine don't seem to be affected.
I've narrowed the source of my problems down to the Left-Channel High Frequency amplifier board. In this system there are two identical boards for the left and right speaker.
A full schematic of the speaker system can be found here:
Klipsch ProMedia 2.1 Schematic
Upon my initial inspection I found a resistor burned out on the board. Further testing found continuity on some of the transistors and a somewhat-puffy capacitor. Long story short, I was in a hurry to get the speakers working again for an event and was careless/frantic in ordering new parts. New parts went it, new parts failed/exploded. Pretty sure that was alllll my fault. SO, I've ordered new parts that I'm sure are the exact replacements this time and not some "close enough" parts.
So here's the terrible
The Left HF board as it sits now:
and after testing, here's the current failures:
Fortunately all of the other components on the board test properly.
I've currently ordered new R15, R17, Q7, Q8, Q9, and Q10.
Also, since R14 was so close to R17 when it went "poof", I'm replacing it even though it tests good.
I replaced all of these same parts (including C3) originally. The first time R17 was burned up, but no other components showed damage. This time Q9 popped but I'm pretty sure it's because I got the wrong components for Q7 and Q8.
All of the parts should be arriving in the next two weeks (Slow boat from China) and I'm hoping that replacing them properly should fix the issue, but my concern here, and what I'm writing all of this for, is what might have caused this in the first place? I just don't want to wire this all up with good, working parts and have them blow again right away because I didn't look far enough up the chain. For the record, I did buy duplicates in case that exact thing happens
I don't remember any one event that would have caused this. I was using the speakers for a party where many people were hooking their phones up to play music. When I moved the speakers back to my computer a few days later the left channel was out, the right channel sounded weak and terrible, and the subwoofer worked as expected.
For those that know what they're looking at in the schematics, what other components should I be testing that are sending a signal (or too strong of a signal) to these boards? I'm hoping the failure is contained to this one HF board but I don't know enough to trace the line back and find exactly where I should be looking for a surge or something.
Any help or guidance is extremely appreciated! Thanks!
I've narrowed the source of my problems down to the Left-Channel High Frequency amplifier board. In this system there are two identical boards for the left and right speaker.
A full schematic of the speaker system can be found here:
Klipsch ProMedia 2.1 Schematic
Upon my initial inspection I found a resistor burned out on the board. Further testing found continuity on some of the transistors and a somewhat-puffy capacitor. Long story short, I was in a hurry to get the speakers working again for an event and was careless/frantic in ordering new parts. New parts went it, new parts failed/exploded. Pretty sure that was alllll my fault. SO, I've ordered new parts that I'm sure are the exact replacements this time and not some "close enough" parts.
So here's the terrible
The Left HF board as it sits now:
and after testing, here's the current failures:
Fortunately all of the other components on the board test properly.
I've currently ordered new R15, R17, Q7, Q8, Q9, and Q10.
Also, since R14 was so close to R17 when it went "poof", I'm replacing it even though it tests good.
I replaced all of these same parts (including C3) originally. The first time R17 was burned up, but no other components showed damage. This time Q9 popped but I'm pretty sure it's because I got the wrong components for Q7 and Q8.
All of the parts should be arriving in the next two weeks (Slow boat from China) and I'm hoping that replacing them properly should fix the issue, but my concern here, and what I'm writing all of this for, is what might have caused this in the first place? I just don't want to wire this all up with good, working parts and have them blow again right away because I didn't look far enough up the chain. For the record, I did buy duplicates in case that exact thing happens
I don't remember any one event that would have caused this. I was using the speakers for a party where many people were hooking their phones up to play music. When I moved the speakers back to my computer a few days later the left channel was out, the right channel sounded weak and terrible, and the subwoofer worked as expected.
For those that know what they're looking at in the schematics, what other components should I be testing that are sending a signal (or too strong of a signal) to these boards? I'm hoping the failure is contained to this one HF board but I don't know enough to trace the line back and find exactly where I should be looking for a surge or something.
Any help or guidance is extremely appreciated! Thanks!