Bose Life CD5 Series I Service Manual page 53

# 177871-B1
Product: CD-5
Subject: Display Failure
Symptom: Flashing VFD displays are being observed on CD-5 units.
Reason: The existing ground trace breaks at the pad leaving no ground. This change
affects PCB P/N 177400 and has been added to all production units starting the week of
12/17/95.
Solution: Repair ground trace.
1. Refer to the disassembly/ assembly procedures to access the Digital PCB.
2. Compare the PCB to the figure below. If a piece of jumper buss wire is present from the
VFD Support tab (closest to pin 21 of U402) to the ground trace, the modification has been
done. If it is not present, proceed to step 3.
3. Scrape the ground trace a 1/4" from the VFD Support tab until the copper is visible.
4. Install a jumper buss wire from the VFD Support tab to the broken ground trace. Be sure
to wrap the wire around the tab once or twice before soldering it to the ground trace.
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