+1 top what spin said - sorry for the lack of responses, this post slipped through somehow.
Good job troubleshooting with swapping the chips. We know it's not a chip issue since the problem did not move with the chip that deals with the hi-band (IC4). We know the pedal is getting proper power since everything else works fine. The resistor, pot, and cap placements all look correct, so that only leaves one likely sources: a bad solder joint. Sorry to sound like a broken record. But I've had builds where I went over the joint half a dozen times before another reflow finally fixed the issue. You might also upload some current photos taken after you reflowed the joints. The photos you provided show very questionable solder joints on the pots.
In my opinion, the symptom you describe sounds very much like one of the pots is not working due to a bad connection, or IC4 is not getting the voltage it needs from the socket.
Here's something you can do if you've able to take voltage readings: compare voltages on IC4 to IC2 and IC3. They should all be basically the same. If you find a voltage on IC4 that seems way off when compared to 2 or 3, that can help us track down the issue. (if you have a meter but are unsure how to use it, please ask before just taking random readings)
If you feel like it might be a component issue (it almost never is), you can also start replacing the components I highlighted is my previous post as dealing with the hi-band.
Login
Register
FAQ
Search
The Hi-band isn't working! The pedal is really quiet, and both the low and mid bands work great. I've taken the pedal apart and gone over as many of the solder joints (on both sides of the board) as I can without removing the pots AND have swapped the TL074s around and still no change. What am I missing? thx for the help.
