Specifications

Australian Monitor
Service Bulletin
AMIS120 Mixer Amplifier
AMIS120XL Mixer Amplifier
AMIS120P Booster Amplifier
AMIS1202P Booster Amplifier
Bridge Rectifier Upgrade
13 March 2012
P
age 1 of 1
Applicable Models
This bulletin applies to AMIS120, AMIS120P, AMIS120XL
and AMIS1202P models manufactured prior to March
2012.
For Information Only
This bulletin is intended for service technicians only and is to be applied when replacing failed bridge rectifiers.
This bulletin does not apply to functional units.
Known Issue
A small number of bridge rectifier failures at power
on have been observed.
Details
i. Failure of the electrolytic capacitors in the positive and negative 12V regulators result in a large DC
offsets at turn on, resulting in failure of the main AC bridge rectifier.
ii. It is believed that RoHS compliant 35A bridge rectifiers are not as reliable as the earlier non-RoHS
equivalents. We have therefore decided to increase the rating from 35A to 50A to provide additional
headroom under turn on conditions.
Solution
i. Replace the electrolytic capacitors in the 12V reg
ulator section as per service bulletin AM-SB-120313.
ii. When replacing a failed AC bridge rectifier, substitute the original 35A bridge with a 50A model as
indicated in the table below.
Model VRRM I(AV) Terminals
O
riginal Part
KBPC3504 400V 35A 0.25" FASTON terminals
R
eplacement Part
KBPC5004 400V 50A 0.25" FASTON terminals
N
otes
 All models manufactured March 2012 or later are fitted with the 50A replacement part.
 Part number KBPC5006 may also be fitted (50A 600V).