Yamaha DRX-1 Service Manual page 48

DRX-1
and select Command mode
48
3. Digital Board-4
DSW MEMORY TESTS
Start Diagnostic Software
Flash Checksum
Command: 100
OK
Flash 1 Write Access
Command: 101
OK
Flash 2 Write Access
Command: 102
OK
Flash Write/Read
Command: 103
OK
SDRAM Write/Read
Command: 104
OK
SDRAM Write/Read fast
Command: 105
OK
NVRAM I2C Test
Command: 123
NVRAM Write Read Test
Command: 122
OK
MEMORY PART OK
- Check IC 7301
NOK
- Check IC 7302
NOK
- Check IC 7301
NOK
- Check IC 7302
- Check IC 7301
NOK
- Check IC 7302
NOK
- Check IC 7300
NOK
- Check IC 7300
- Check I2C-signals
NOK
- Check 7201
Fig. 7