+12volt unregulated is dipping down below 10.4 volts , your issue is not uncommon with system 11 mpu's , i had issues that were fixed with a new power supply board , if you have clips on the meter monitor your +12 while you start it up and see what happens to the voltage while things are happening when you play and such , i mean either 12 is being pulled down by something or the 12 is just not stable , i noticed that it happened more for me when the back box was closed instead of opened and i figured heat was effecting my taxi in the back box so i placed a hair dryer on parts of the back box and heating the power supply +12 was very sensitive so i replaced it and long story short it works much better now , so get clips be very careful not to let any thing slip and short out , monitor your unreg +12v ( 5v is derived from the +12v if i remembered right) but the reset is caused by the +12 line , also sound board can pull it down so you can unplug power to it and test +12 , for me the 5volt never was out of tolerance