Chosen Solution
Hi, I have a Yamaha AV Receiver, DSP-A1092 and I’m not able to find exactly what is the problem. The outputs are not working, except for the front effect (R and L). I know could be the logic board, the amp or relays. The folder with manuals (Owner’s manual and Service Manual). If anyone helps me to figure out what it’s I would be so happy, thanks.
From a quick scan of the service manual, each set of speakers has its own protection relay and relay driver transistor. I would start looking there. It is possible that the relay drivers are not working or that they are being told NOT to trip the relay because of over current detection. Check those transistors as well (Q165,167, 170, 173,176,179, 205 and 211). See page 44ofthe service manual for the reference (lower right hand corner). The power amp for the front speakers is an IC while the other channels use discrete transistor amp circuits. These too could have a problem. Since all channels except for the front seem to be out, I would look for a missing voltage that supplies all of the discrete amp sections. Dan
