| Electronics > Repair |
| Marantz SR5200 amp damaged center channel + DAC issues |
| << < (4/8) > >> |
| poot36:
So should I bother trying to correct the offset or will it make no difference? All the output channels are clones of each other. I assume I would want to adjust the two 22K resistors to adjust the bias correct? |
| coromonadalix:
If it work Don't play anymore with it, an 0.063V dc is okay at the output, it wont fry the speaker, enjoy your cinema ... |
| poot36:
Sorry for the late reply. I wont mess with it. I now have the replacement DAC installed and I still have no sound from any of the speakers unless I put it in stereo direct mode which bypasses all of the digital sound processing circuitry. Interestingly I do get some nonsense sound for a second or so when changing the surround sound mode but that is it. I have power to the DAC and SCLK as well as LRCK. I am not sure about SDATA and the AMUTE and BMUTE appear to be operating in reverse to what I would expect (high when there is sound and low when there is no sound). On SDIN1, SDIN2, and SDIN3 I get a constant high or low but no changing data when selecting the different surround modes. Got any ideas? |
| mzacharias:
I have replaced a number of the DAC/electronic volume control IC, IC720 - a CS4391KZ, mainly on the SR-7200 model. Exactly your problem symptom. They're dirt cheap from UT Source. Also, this series has lots of bad front panel tact switches. Available cheap from eBay (China). Takes a couple weeks to get them. |
| poot36:
Ok, I have attached a picture of the relevant section of the schematic. This unit has a separate volume control IC on a different board and it does work properly. The DAC I replaced is a CS4228A and as they are discontinued I had to get it from China so I guess that it could be a fake. Interestingly it is connected to another DAC (CS4391) for just the FR and FL channels (it is IC720 in the picture as the bottom of it is cut off). Got any ideas of what to measure now to try and figure out what my issue is? |
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