Bose 1800

28
SERVICE BULLETIN
Subject: Output Transistors Date: 10/13/1980
Remarks:
Due to supply demands, Bose
®
Corporation has changed the output transistors on the PM-2
and the 1800 amplifier boards currently being produced. The transistors have been change
from Bose P/N 102433 (2N5840) to P/N 117579 ( Motorola MJ15011). The new output transis-
tors are not compatible with the original 102433 transistors. If you service an 1800 power
amplifier or PM-2 mixer, check the serial numbers on the printed circuit board and the P/N on
the output transistors to see which output device is being used. Below is a list of the approxi-
mate serial number break for the newer P/N 117579 transistors.
PM-2 Boards: Approximately 30800 and above
1800 Boards: Approximately 30800 and above
PM-1 Boards: All have P/N 102433
1801 Boards: All have P/N 102433
When replacing output transistors, you must use the correct replacement device. Older units
with P/N 102433 on the output transistors must be replaced with 102433 (2N5840) transistors.
Units with output transistors with P/N 117579 must be replaced with 117579 (MJ15011) transis-
tors.
Bulletin # Pro-81-001