Originally Posted by ahblaza
What I've done so far: I connected up some speaker cable to a couple binding posts I had laying around and connected the posts to the inputs on the XO board. I did the same with the CD/WG wired to the + - HF inputs. I did this to the bad board and the never used center XO board as well. Now I had to identical setups to work with.
I connected the bad board with the speaker cables from the amp (banana plugs) to the binding posts I wired to the XO. I played some music with a lot of piano sounds and the bad CD XO baord setup had sound coming from the CD but very faint, I also had the left speaker playing so I really couldn't tell if the CD had the same output, of course the speaker sounded wonderful.
Next I hooked up both CD/WG XO boards to the L & R speaker cables using the binding posts to plug the speasker cable into. I played music again and I heard sound from both the bad and never used boards but very faint at -30 dB.
I decided to try running some AVR test tones through both of the XOs and made sure the trim levels were set to the lowest value before playing the pink noise signal. I ran the tones through the bad board first and heard the sounds and slowly turned up the trim level to see if it would get louder and it did. I did the same think for the unused XO board and got the same results.
Then I set each L & R channel trims to -7dB and ran the tones again through each XO board and measured the output of each board separetly with an SPL meter and each board with CD connected measured exactly the same. So I do have sound from the CDs. I can run a lot of tests with the bad board since I have it configured this way with binding posts attached and the CD hooked up as well. The pic is what I have.
I went all around the bad board today and checked again for any solder shorts and found none. I scraped in between each copper pad to make sure nothing was shorting to another pad.
First off, by using the unused board, you introduced another variable since you don't know for sure whether the unused board is working or not. I recommend you do the testing/comparison with the known working channel. If you need to, run a high freq test tone (6-8kHz) to compare the KNOWN good and the bad boards. If you prefer to use pink noise instead, disconnect the mids and LF on the good speaker so you can compare only the CDs.
Once you have a good idea of how loud the CD should be, you can turn off the other channel and start concentrating on the bad board. Connect the CD - terminal to the long connector. Check for continuity between CD- and the copper on the bottom side of the board where the connector is soldered. This eliminates the (-) connector as the bad part. Assuming you have the input of the XO connected to your amp, do the following using the 6-8kHz test tone:
1. Touch the CD + to IN+ on the XO. You should hear the sound loud and clear. If not check you setup
2. Touch the CD + the junction of 3ohm resistor connected to IN+ and the 6.2 uF capacitor. If no or weak sound, desolder on end of the resistor and measure.
3. Touch the CD + the junction of 6.2uF capacitor / air core inductor / 3 ohm resistor (this is your HF+). If no or weak sound here are the possible causes:
- bad capacitor - short across it, see if the sound increases
- bad 3 ohm resistor - disconnect and measure
- shorted inductor - remove and check sound again
Cold/bad solder will also cause this problem but looking at your board it looks like it is soldered well. Do these and if you still cannot figure it out we will try some more things.