Service Bulletin - JBL SOURCE Service Manual

Dolby pro-logic surround processor/cd player/tuner (part of the esc350 & 550 systems)

Hide thumbs

Table Of Contents

Table of Contents

Dolby Pro-Logic

Surround Processor/CD Player/Tuner

Service bulletin JBL9704 - July 1997

To: All JBL Service Centers

Models: ESC550 - The Source

Subject: Surround level changes during CD search mode

In the event you receive a ESC550 system (including the Source) with the complaint that the

surround level (rear channel volume) changes during the CD search mode:

Procedure:

1) Lay unit face down. Remove the 5 Phillips screws holding the upper & lower case together;

separate cases.

2) Locate C707 (.022uf 50v cap.) on the main PCB in the bottom case.; replace with 470uf 10v

electrolytic capacitor (JBL# 3479347121). Observe polarity; negative terminal should be closest to

connector CN702. It should be possible to cut the original cap off the board and re-solder the

replacement without removal of the main PCB. See drawing.

3) Locate solder pads for connector CN702 on the Control PCB in the upper case, near the

headphone jack. Adjacent to the slot cut in the PCB for the 11 conductor cable, solder a .01uf

ceramic cap (JBL# 3519103935) to pins 8 and 11 on the solder pads. See drawing.

4) Re-assemble unit; test as follows:

a) Plug in unit, assure all cable and speaker connections are intact. Insert CD of choice.

b) Turn power ON to the Source and the Bass550 subwoofer; (display on the Source

should now be active).

c) Toggle "surround mode" button on front panel or with remote control until "NORMAL"

appears.

e) Adjust volume (on the Source) so display reads "VOLUME 30".

d) Press PLAY button on the Source or the remote control.

e) Press the SEARCH/TUNE button on the Source or the remote control to search up or

down selected track.

Model

ESC550 (Source)