@andro6600 have you by any chance had the control pod open? and been in and out of there alot? i had a similar issue to what you are describing and mine was because i was moving the control pod LCD alot and the wires broke on me (the second time was hard to tell because i could not see under the white glue) but i replaced that connector with a plug and socket type connector i got of something else and never had that problem again. i thought to myself (not knowing how it works) would the display just not work? but twice it happened to me and twice it was fixed by repairing that connector. just check that connector and make sure it is ok... i know you have not said you have been in there in your post but i can remember that i had a problem like that... i was sat listening to music on low volume for about half an hour while i was on the laptop and the sound just went off... then i bypassed the pod and everything was fine... so i had a look at the pod and found the wire broke... so i fixed it once then it happened again so i swapped the connector for a more robust one that i could unplug when needed. did not do it again after that.
little update on mine... on my main system i broke the tracks for the front right and the front left and center (2 op-amps total) and getting them things in and out again was getting worse and worse and once they was in i had to use a link wire for the broken tracks. so i bought some soic to dip adapters from ebay and epoxied them to the board (near the original and not over any small ground points on the board) i then used ethernet cable (multi core cable not single strand) to link back over to the correct smd components (i used the test meter first to find out where everything went and which pins where joined) i removed all the tracks on both of these positions and just soldered the wires directly to the smd's... then tested continuity from the smd component to the chip leg... and then again tested the other side of the smd components to make sure the smd was ok and my solder joint (wire to smd) was connecting to the track on the board... all is ok and all wires are epoxied in place (does not look nice... but its a fix) all wires read very low resistance.
The new op-amps have arrived today and i will be taking extra care of installing these ones... the last ones i was rough with them.. no anti static wrist strap and had them in my hand... and when i put them in last time i had the op-amps hot... where you could not keep a finger on them... i have since got a new soldering iron (regulated one) and had practice on installing the op-amps without getting them hot (removing them is a bit different lol) so hopefully if nothing else is broke... it should be back up and running soon.