Yamaha RX-V350

[warb]

Hi all,
I recently bought a cheap Yamaha RX-V350 surround receiver that was sold as defective. According to the previous owner the 'codec IC' was causing the problem. I think by that they meant the DSP chip, since I cannot get it to process any surround signal. All channels work fine when I hook up a separate processor on the 6-channel input, but when I try to use a digital input or process an analog signal with Prologic, the relais click and I get no sound at all (only very very faintly at max. volume). Does this mean the DSP is gone or is to more likely to be another component, e.g. the power feed to the DSP. If it is is the DSP, would it be possible to just replace the whole board that houses it and what would be the costs? I've got some repair experience and am pretty good at soldering. I would really like to save this piece if costs aren't too high. Hopefully someone can help me with it. Thanks in advance.