Read JBL PB 12 (serv.man11) Technical Bulletin online
JBL Incorporated 250 Crossways Park Dr. Woodbury, New York 11797
Service
Bulletin
Service Bulletin JBL2001-07 Rev1 - February 2002
This is considered a Minor repair
To:
All JBL Service Centers
Model: PB12 (Revision 1 only)*
Subject: Possible Missing Diode D4
In the event you receive a PB12 subwoofer for any servicing reason, check for the presence
of diode D4 on the Main PCB close to the Power Amp Module (see illustration). If D4 is missing
or has been “cut out” of the circuit, it should be replaced; add JBL part# 50115. Observe
polarity.
Note: The presence or absence of D4, in itself, does not contribute to, or solve, an amplifer failure.
Purpose of D4 is to reduce the possibility of an occasional Turn-OFF pop noise.
Reference for general location only; all parts or designators may not conform exactly to this drawing.
* Revision 1 of the PB12:
Amplifier faceplate says “Made in Canada”; Amplifier serial number starts with “AM”
Black (or silver) potted, non-serviceable S64AMI output module.
Black (or silver) potted, non-serviceable S64AMI output module.
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