Yamaha n8, Service Manual

Page: 131 / 245

131
n8/n12
DESCRIPTIONS ON TEST POINTS OF THE DM CIRCUIT BOARD
Contents of test points set up on the soldered surface (the surface which is visible when the bottom cover is opened) of the DM circuit
board for the n8 and n12. (See page 139 for overall view)
Signal
type
Test point
No.
PWB
indication
Signal
name
Description
Electric
specifi cations
Reference
GND
Power supply
voltage
TL200 +1.8 V +1.8 V
+1.8 V power for the CPU core of the SSP1. Produced from the +3.3
V at the DC/DC converter (IC101).
+1.8 V ±3 % DGND
TL201 -5 V -5.0 V
-5 V power for the Op-Amp of the PN, PNSB circuit board.
Produced from the +5 V at the DC/DC converter (IC188).
-4.275 V to -5.25 V DGND
TL202 +3.3 V +3.3 V Digital circuit 3.3 V power. Provided by the PS circuit board. +3.3 V ±5 % DGND
TL203 +5 VD +5.0 V Digital circuit 5 V power. Provided by the PS circuit board. +5.0 V ±5 % DGND
TL204 +1.5 V +1.5 V
+1.5 V power for the Talkback microphone Phantom. Produced with
resistive potential divider from the analog 15 V.
+1.5 V +5 %/-8 % AGND
TL258 DGND D.GND Digital circuit system GND. –
TL205 +15 VD +15 VD Power for the audio system A/D, D/A. Provided by the PS circuit board. +15 V ±5 % VSS
TL206 +15 VA +15 VA
+15 V power for the audio system Op-Amp. Provided by the PS
circuit board.
+15 V ±5 % AGND
TL207 -15 VA -15 VA
-15 V power for the audio system Op-Amp. Provided by the PS
circuit board.
-15 V ±5 % AGND
TL208 +5 VA +5 VA
Power for the audio system A/D, D/A. From the +15 VD, 6 V
by the DC/DC converter (IC127) and 5 V by the 3-terminal
regulator (IC187).
+5.0 V ±2 % VSS
TL259 VSS VSS GND for the audio system A/D, D/A. –
TL260 AGND A.GND GND for the audio system Op-Amp. –
A/D input
TL209
ADI1
ADI[1]-(+) A/D converter input hot side of INPUT CH1. Full-scale input: 2.9 Vp-p AGND
TL210 ADI[1]-(-)
A/D converter input cold side of INPUT CH1
(phase opposite to the hot side phase).
Full-scale input: 2.9 Vp-p AGND
TL211
ADI2
ADI[2]-(+) A/D converter input hot side of INPUT CH2. Full-scale input: 2.9 Vp-p AGND
TL212 ADI[2]-(-)
A/D converter input cold side of INPUT CH2
(phase opposite to the hot side phase).
Full-scale input: 2.9 Vp-p AGND
TL213
ADI3
ADI[3]-(+) A/D converter input hot side of INPUT CH3. Full-scale input: 2.9 Vp-p AGND
TL214 ADI[3]-(-)
A/D converter input cold side of INPUT CH3
(phase opposite to the hot side phase).
Full-scale input: 2.9 Vp-p AGND
TL215
ADI4
ADI[4]-(+) A/D converter input hot side of INPUT CH4. Full-scale input: 2.9 Vp-p AGND
TL216 ADI[4]-(-)
A/D converter input cold side of INPUT CH4
(phase opposite to the hot side phase).
Full-scale input: 2.9 Vp-p AGND
TL217
ADI5
ADI[5]-(+) A/D converter input hot side of INPUT CH5. * n12 only Full-scale input: 2.9 Vp-p AGND
TL218 ADI[5]-(-)
A/D converter input cold side of INPUT CH5
(phase opposite to the hot side phase). * n12 only
Full-scale input: 2.9 Vp-p AGND
TL219
ADI6
ADI[6]-(+) A/D converter input hot side of INPUT CH6. * n12 only Full-scale input: 2.9 Vp-p AGND
TL220 ADI[6]-(-)
A/D converter input cold side of INPUT CH6
(phase opposite to the hot side phase). * n12 only
Full-scale input: 2.9 Vp-p AGND
TL221
ADI7
ADI[7]-(+) A/D converter input hot side of INPUT CH7. * n12 only Full-scale input: 2.9 Vp-p AGND
TL222 ADI[7]-(-)
A/D converter input cold side of INPUT CH7
(phase opposite to the hot side phase). * n12 only
Full-scale input: 2.9 Vp-p AGND
TL223
ADI8
ADI[8]-(+) A/D converter input hot side of INPUT CH8. * n12 only Full-scale input: 2.9 Vp-p AGND
TL224 ADI[8]-(-)
A/D converter input cold side of INPUT CH8
(phase opposite to the hot side phase). * n12 only
Full-scale input: 2.9 Vp-p AGND
TL225
ADI9
ADI[9]-(+) A/D converter input hot side of INPUT CH9. * CH5 on n8 Full-scale input: 2.9 Vp-p AGND
TL226 ADI[9]-(-)
A/D converter input cold side of INPUT CH9
(phase opposite to the hot side phase). * CH5 on n8
Full-scale input: 2.9 Vp-p AGND
TL227
ADI10
ADI[10]-(+) A/D converter input hot side of INPUT CH10. * CH6 on n8 Full-scale input: 2.9 Vp-p AGND
TL228 ADI[10]-(-)
A/D converter input cold side of INPUT CH10
(phase opposite to the hot side phase) * CH6 on n8
Full-scale input: 2.9 Vp-p AGND
TL229
ADI11
ADI[11]-(+) A/D converter input hot side of INPUT CH11. * CH7 on n8 Full-scale input: 2.9 Vp-p AGND
TL230 ADI[11]-(-)
A/D converter input cold side of INPUT CH11
(phase opposite to the hot side phase). * CH7 on n8
Full-scale input: 2.9 Vp-p AGND
TL231
ADI12
ADI[12]-(+) A/D converter input hot side of INPUT CH12. * CH8 on n8 Full-scale input: 2.9 Vp-p AGND
TL232 ADI[12]-(-)
A/D converter input cold side of INPUT CH12
(phase opposite to the hot side phase). * CH8 on n8
Full-scale input: 2.9 Vp-p AGND