More 300E Ignition control unit problems.

[pezzy]

I actually have a question about ignition control units going bad. Well my car has been in the shop almost 3 weeks now. I first bought a used ignition control unit at a junkyard but it ended up being for a different car but it was good, I went and traded it in for a different one and got the right one but this one does not work. I was wondering, is it possible that these things may go bad when the car is in an accident or just be bad cause of corrosion. I would like to know if I am just wasting my time with that junkyard. I found a new unit for $786 and was wondering is there any place that offers rebuilt units or used units that they know will work? Mercedesshop does not carry the ICU for my car so thats not an option. Thanks for all your help.