If you have a look inside EII you will notice that -EVERY- chip (and there are over 300 of them!) is socketed. Where this might have seemed like a good idea at the time it was a disaster as, with time, these low grade sockets oxidise and develop poor connections. It's one thing having a few dry solder joints to deal with - it's another having over 5000 potentially poor connections. This is why, if your EII starts to play up, it's by far most likely that one of the chips needs to be reseated in it's socket.
The problem is made worse by the fact that the two main pcbs in EII are huge and cover 75% of the large metal base plate. These pcbs are rigidly mounted to this plate and thus when EII flexes so do the pcbs. This is why EII can often fail after being moved.
My EII recently developed a fault - after moving it the sample input signal failed (which -really- upset me!). I tracked the problem down to an IC in the ADC stages which needed to be removed, sprayed with contact cleaner and reseated in it's socket.
With lord knows how many hundred chips in this beast it's no wonder they have a reputation for being a bit flakey.
If E-mu had chosen turned pin sockets - it would have been a very different story.... it also would have been several hundred dollars more expensive! (as if $10,000 wasn't enough)
Our EII's are now well over 20 years old - in damp climates the pins on these sockets will look like they've been residing on the bottom of the sea - so get your contact cleaner at the ready and pray
EII's SEA OF IC SOCKETS:
The Mac was the last thing to die on me....cost three times as much as what I paid for it to get that repaired !!
