BOSE 264563 B3 Schematic

264563-B3

Lifestyle® AV28 Media Center, US and European models

Product reliability issue

Inspect orientation of C839 on all units that come in for repair with a date code before 2200
(200th day of the year 2002).

Symptom: None or dead unit

Reason: C839 electrolytic cap installed backward

Solution: On all units with a date code before 2200 that come in for repair, inspect the orientation of C839

located on the main PCB. This would apply to units with all revisions of main PCB P/N: 254135 and
revisions 00 - 02 of main PCB P/N: 267026. The orientation of C839 should match the picture below. If it
doesn’t, remove surface mount electrolytic capacitor C839 and install a new part (part number 256772-331A)
in the direction indicated below. The negative (marked) lead of the capacitor should face toward J102 and
away from Y700. Note that prior to part number 267026-001 rev 02, the correct orientation does not match the
silkscreen. After the part is replaced, the capacitor polarity on the board will match the polarity shown on the
schematic, sheet 9 of 11 for the main PCB.

After correcting the orientation of
C839, if the product doesn’t operate,
you may also need to replace the
+2.5V regulator U806. If the +2.5V
is present and the unit still doesn’t
function, you may need to replace the
CS98000 DVD decoder IC U1.

Note: This is a product reliability
issue, and not a safety issue.

Refer to the AV28 service manual,
part number 264563, for disassembly/
assembly and test procedures.

CQE
7/02