Serial Numbers: JP1KK0000 to JP1KK9999, MY4210000 to MY42401271 When E5070B has the old step attenuator (33321-60059) and Internal Test fails at Step Attenuator test group, replace the old step attenuator (33321-60059) by improved version (33321-60068), add additional cable and update firmware to 5.02 or later