Freighterman - it's interesting that you recommend following the Troubleshooting Trees "to the letter". I'm assuming that the Airbus ones must be better than Boeing's. I tend to avoid Boeing's Fault Isolation Manual. After doing my own troubleshooting via the Schematics and AMM, I can see the pattern that they have adopted but I've found their methods a little "Shotgun" for my liking and often way off base. Unfortunately with the 747-400, suffering from it's normal "Digital Hypercondriac", it throws a CMC message with it's associated number and you have to trot off to the FIM. I'll be interested to see the Airbus equivalent.. .. .Seldomfixit - Can't wait to see the "Superior" Airbus MM system! Can you believe we are still using the Microfilms and hard copy books for all of our Boeings? Apparently we are one of the last airlines to be using it. The Computer Server based system for our Boeings (except 747 classic) is being incorporated as we speak (probably because Airbus have this or nothing). Our IT guys came out to give demos. It was like a stage show with the boys giving Oooohhhs and Aaaahhhs at all the right places!. .. .Everyone Else - Thanks for your replies so far. Interesting times ahead!