A customer's 4200 seems very buggy and we need to try a firmware upgrade. Could anyone explain the procedure for this please?
The system is running on 4.0 at the moment (though the AC card boot s/w shows as 3.2 for some reason

I have obtained 4.3 firmware which unzips the following files:
a30818eq.aa1
c30819eq.aa1
d30820eq.aa1
And I've ordered new AC and CM boards just in case. I do not know what software (if any) will be supplied with these.
Any help greatly appreciated!