Bose AM-30P Servicehandleiding - Pagina 29
Blader online of download pdf Servicehandleiding voor {categorie_naam} Bose AM-30P. Bose AM-30P 49 pagina's.
TEST SET-UP PARAMETERS
Before performing the tests described in these procedures, use the following test setup
parameters.
SPEAKER OUTPUT LOADING
All tests are to be performed with speaker outputs unloaded except for those specified in the
Amplifier Test. Outputs should be loaded as listed below.
POTENTIOMETER SETTINGS
Potentiometers R50 (treble control) and R306 (bass control) should be set to the center
position.
TURN-ON
Apply AC mains voltage. Wait 100ms and apply +10VDC between J5 Pin 1 and 7, or (if
connected) power CD-20 on. Pin 7 is the ground reference point which has to be connected.
MANUAL TEST MODE
The microcontroller can be manually configured to operate in several different "Test Modes" to
facilitate input/output troubleshooting and repair without the need for a CD-20 music center (to
provide serial data commands to the microcontroller). This is necessary because, by default, all
volume control ICs (U8, U9, U12) are at minimum volume and all power amplifier stages are
muted in the absence of serial data input. The test modes are induced by grounding Pins 25, 26
and 27 (*labeled TEST 3, TEST 2 and TEST 1 on the top side of the PC board) of U601 as
follows:
Note: Ground out the test mode pins before powering up the AM-30P unit.
Test Modes
NOTE: To access this section of the PC board the top cover must be removed.
29