Yamaha P-115B Service Manual page 65

Power ON
Boot
Main
Starts initialization task
Cancels DAC-IC Reset
With backup ROM
PCM initialization
Backup data initialized
Cancels interrupt mask
Completes initialization task
After 100 msec.
If it boots but does not run up to here,
the PROGRAM ROM (IC105) usually
is not the problem.
SWX03 (IC100) is defective.
YES
Test Program ?
NO
Without backup Rom
Backup data initialized
Sound can be played by PAD/MIDI
Normal operation
P-45B
150pin (PB0) L → H
138pin (PB1) L → H
Starts Test Mode
(A3 sine wave is output)
The keyboard is defective if it is
impossible to enter the test
Test program routine
P-115B/P-115WH/P-45B
65