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