My voltages are referenced to Gnd (at the RCA), not from one pin to another.
On the + and - inputs, there was only a couple mV difference in the four pins.
The lowest was 117mV and the high was 119mV. And of course, the +2.5 and
-2.5 supply voltages. The output offset should be less than 10mV but a little
higher is not uncommon in the pupDAC.
Okay, i did this first. Pin 1 & Pin 2 & Pin 5 are 120mV, Pin 6 307mV!!!
Here are some suggestions:
It's hard to tell - your photos are great - but some of the solder joints may be cold. In particular, it appears that some of the resistor leads look like they've been poked through the solder. I'm sure that's not the case, only that it's some indication the joint may be cold. So, be methodical about it, but start with the through hole resistors and see if you can re-flow the solder on their joints. For instance, R14 and R15 take the Right channel outputs from the DAC chip directly. If there's something faulty in the connection there, that may explain the lack of audio output in the right channel. Go through all the resistors this way, stop, then re-measure with the power off and check for good continuity throughout the circuit. A way to do this is - with power off - touch one DMM probe to the output pin on the DAC chip, then touch the other probe to the far lead (toward the opamp) of the resistor. If you can read zero ohms, then things are OK. Do this for the C3 and C18 mica capacitors, too. While you're at it - also check L5. One of the capacitors is blocking it, but it looks a bit dodgy on the right side.
Let us know what you find when you have a chance.
After that, i reflowed almost every through-hole part, but they were all good. All continuity checks were successful. I re-measured all resistor values for correctness.. no error there. Still no audio on the right output. After getting a little bit upset, i wanted to swap the opamp with the other provided (thanks again tomb for the fast shipping and so on). But as i started to remove the solder, i noticed after heating a pin, the solder kind of flowed beneath the lead. So, i tought rinsing it again with flux and reflow all pins and yes, that somehow did the trick. From the visual perspective, the solder joints looked really good (as far as i can judge that). But now, everything works like a charm!!! Next step will be putting it inside my PPAv2 amp to be used at my workplace, because i'm not allowed to switch my sound card ;)
Thank you very much avro and spacially tom for your help and dedication. I really appreciate that!