Service Bulletin; Cd5 Troubleshooting Guide - Bose Life CD5 Series I Service Manual

Symptom
Hum
Intermittent or no operation
No operation
Display Dim
Display Flashes
Will not track or focus. CD
mechanism not the problem
No laser output
One or more of the unit's
functions do not operate
using controls on center but
work with remote
No remote control operation
No FM
No audio output
Distorted output, CD only
Customer complains that
CD does not operate. CD
operates after unit is
unplugged and plugged in
again.
CD will not operate.

CD5 TROUBLESHOOTING GUIDE

Probable Cause
C2, physical damage
P1, fractured solder joint or
lifted pad
Q2, 3, 4, 5 failed
C19 voltage under rated
Ground break at VFD
support tab
U503 or U501
Solder short across C502
Defective switch
Remote control receiver not
properly soldered
X301 defective
U101 (multiplex IC)
defective
Defective U506 (D/A
converter) or poor solder
connection
CD micro is not resetting
under certain conditions
C13, located in the power
supply, has a bad
connection causing low
voltage on pin 1 (≈ 14V)
and pin 16 (≈ 4V) of U503
or U504.
Solution
Replace C2
Repair fractured solder joint
or lifted pad.
Replace Q2, 3, 4, 5.
Replace C19 with a 33uF,
63V cap part number
149948-3301J.
Repair ground break at VFD
support tab located near
U402, pin 21.
Ensure U501 and 503 is
properly soldered. Check
U501 and 503 for proper
operation.
Remove solder short from
C502 and check Q501.
Replace switch.
Remove solder from legs of
remote receiver and scrape
legs and then solder
Replace X301
Replace U101
Ensure U506 is properly
soldered or replace U506
See service bulletin 181473
for reset modification
procedures.
Repair fractured solder joint
or damaged track.
54
Service
Bulletin
174798-B1
177871-B1
181473