Yamaha PortaTone PSR-550 User manual

SERVICE MANUAL
■ CONTENTS
SPECIFICATIONS.............................................................................. 3
PANEL LAYOUT ................................................................................. 4
CIRCUIT BOARD LAYOUT & WIRING .............................................. 6
BLOCK DIAGRAM ............................................................................. 8
DISASSEMBLY PROCEDURE .......................................................... 9
LSI PIN DESCRIPTION ................................................................... 13
IC BLOCK DIAGRAM....................................................................... 18
CIRCUIT BOARDS .......................................................................... 19
TEST PROGRAM ............................................................................ 28
DATA BACKUP & INITIALIZATION .................................................. 32
ALERT MESSAGE LIST .................................................................. 33
MIDI IMPLEMENTATION CHART .................................................... 35
OVERALL CIRCUIT DIAGRAM
PARTS LISTThis document is printed on chlorine free (ECF) paper with soy ink.
1.412K-667 Printed in Japan ’01.05
PK 001654

PSR-550
2
IMPORTANT NOTICE
This manual has been provided for the use of authorizedYamaha Retailers and their service personnel.It has been assumed
that basic service procedures inherent to the industry, and more specificallyYamaha Products, are already known and
understood by the users, and have therefore not been restated.
WARNING : Failure to follow appropriate service and safety procedures when servicing this product may result in
personal injury, destruction of expensive components and failure of the product to perform as
specified. For these reasons, we advise all Yamaha product owners that all service required should
be performed by an authorizedYamaha Retailer or the appointed service representative.
IMPORTANT : This presentation or sale of this manual to any individual or firm does not constitute authoriza-tion,
certification, recognition of any applicable technical capabilities, or establish a principal-agent
relationship of any form.
The data provided is believed to be accurate and applicable to the unit (s) indicated on the cover.The research engineering,
and service departments ofYamaha are continually striving to improveYamaha products.Modifications are, therefor, inevitable
and changes in specification are subject to change without notice or obligation to retrofit.Should any discrepancy appear to
exist, please contact the distributor’s Service Division.
WARNING : Static discharges can destroy expensive components. Discharge any static electricity your body
may have accumulated by grounding yourself to the ground bus in the unit (heavy gauge black wires
connect to this bus).
IMPORTANT : Turn the unit OFF during disassembly and parts replacement. Recheck all work before you apply
power to the unit.
WARNING : CHEMICAL CONTENT NOTICE !
The solder used in the production of this product contains LEAD. In addition, other electrical/electronic and/or plastic
(where applicable) components may also contain traces of chemicals found by the California Health and Welfare Agency
(and possibly other entities) to cause cancer and/or birth defects or other reproductive harm.
DO NOT PLACE SOLDER, ELECTRICAL/ELECTRONIC OR PLASTIC COMPONENTS INYOUR MOUTH FOR ANY
REASON WHAT SO EVER!
Avoid prolonged, unprotected contact between solder and your skin!When soldering, do not inhale solder fumes or expose
eyes to solder/flux vapor!
If you come in contact with solder or components located inside the enclosure of this product, wash your hands before
handling food.
■WARNING
Components having special characteristics are marked Zand must be replaced with parts having specification equal to
those originally installed.

PSR-550
3
■ SPECIFICATIONS
Keyboards
• 61 standard-size keys (C1 — C6) with
touch response.
Display
• Large multi-function LCD display
Setup
• STANDBY/ON
• Master Volume : MIN — MAX
Demo
• 9 Songs
Realtime Controls
• Pitch Bend wheel
Control & Number Buttons
• SONG
• STYLE
• MUSIC DATABASE
• VOICE L
• VOICE R1
• VOICE R2
• VOICE CHANGE
• MIXER
• NEXT/BACK
• DIRECT ACCESS
• EXIT
• Data dial, [1] — [0], [+/YES], [-/NO]
Overall Controls
• Tempo : 32 — 280
• Transpose
Voice
• 219 Panel Voices +14 Drum Kits + 480
XG Voices
• Polyphony : 32
• Voice Set
• R1/R2/L Voices
• Part on/off (R1/R2/L)
• Voice Change :Voice number
• Mixer :Volume, Octave, Pan, Reverb
Depth, Chorus Depth, DSP Depth
Auto Accompaniment
• 112 Styles
• Accompaniment Track :RHYTHM SUB/
MAIN, BASS, CHORD
1/2, PAD, PHRASE1/2
• Accompaniment Track Settings :ON/OFF
• Accompaniment Control :ACMP ON/OFF,
SYNC START, SYNC STOP, START/STOP,
INTRO, MAIN A/B (AUTO FILL), ENDING/
rit
• Beat Indicator
• Accompaniment Volume
• Voice Change :Voice number
• Mixer :Volume, Pan, Reverb depth,
Chorus depth, DSP depth
• One Touch Setting
• Fingering Mode : Multi Finger/Single Fin-
ger/Fingered 1/ Fingered 2/Full Keyboard
Music Database
• 220
Multi Pads
• 40 Multi Pad Banks
• 4 Pads + STOP
• Chord Match
• Naming
Amplifiers
• 6W + 6W (when using PA-6 power
adaptor)
• 4.5W + 4.5W (when using batteries)
Speakers
• 12 cm (4-3/4") x 2, 3 cm (1-3/16") x 2
Power Consumption
• 22W (when using PA-6 power adaptor)
Power Supply
• Adaptor :Yamaha PA-6 AC power
adaptor
Rated Voltage DC 10-12V
Rated Current 2A
• Batteries : Six“D” size, R20P (LR20) or
equivalent batteries
Dimensions (W x D x H)
• 952 x 387 x 169 (mm)
(37-1/2" x 15-1/4" x 6-5/8")
Weight
• 8.7 Kg (19.2 lbs.) excluding batteries
Supplied Accessories
• Data Disk
• Music Stand
• Owner’s Manual
Optional Accessories
• Headphones : HPE-150
• AC Power Adaptor : PA-6
• Foot Switch : FC4, FC5
• Keyboard Stand : L-6, L-7
Digital Effects
• Reverb : 24 types
• Chorus : 16 types
• DSP (system/insertion) : 74 types
• Harmony/Echo : 22 types
Registration Memory
• 32 Registration Banks : 1 — 4
• Naming
• Accompaniment Freeze
Disk Operations
• Song playback/recording
• Load (Style/Multi Pad/Registration
Memory)
• Save (Style/Multi Pad/Registration
Memory)
• Utility : Format, Song Copy, Delete File
Song
• Song Volume
• Song Track Settings : ON/OFF
• Repeat Play
• Song Transpose
Song Recording
• Quick Record, Multi Record
• Recording Tracks : 1 — 16
• Punch In/Punch Out
• Quantize
• Naming
• Clear
• Setup Data :Volume, Octave, Pan, Reverb
depth, Chorus depth, DSP depth
Multi Pad Recording
• User Pad Bank :4 (41 — 44)
• Naming
• Clear
• Chord Match
Style Recording
• User Styles : 3 (113 — 115)
• Recording Tracks :6 Sections x 8 tracks
• Drum Cancel
• Quantize
• Naming
• Clear
MIDI
• Transmit settings
• Receive settings
• Local Control
• Clock
• Initial Data Send
• MIDI template
Other functions
• Metronome
• Upper Octave
• Master Tuning
• Scale Tuning
• Split Point
• Touch Sensitivity
• Voice Set
• Footswitch function
• Pitch Bend Range
Auxiliary Jacks
• DC IN 10-12V, PHONES/OUTPUT,
SUSTAIN, MIDI IN/OUT, TO HOST

PSR-550
4
■ PANEL LAYOUT
● Top Panel
A3
69
C
2
B3
71
R
2
66
G3
67
S
68 70
C4
72
H
73
L
D4
74 75
H
E4
76
L
F4
77
H
78
L
G4
79
H
80
L
A4
81 82
B4
83
H
C5
84
L
85
S
87
D5
86
L
E5
88
H
F5
89
L M
90
G5
O
91
A5
9392 94
B5
95
C6
96
9
REC
10
REC
11
REC
12
REC
13
REC
14
REC
15
REC
16
REC
MEASURE BEAT
/YES
TRACK(1~16)
PART DIAL
0~9
M
U
S
I
C
DA
T
A
B
A
S
E
SONG
STYLE
VOICELR12
E
ASY
VI
GATOR
n
d Piano
DSP(FAST)
SUSTAIN HARMONY
TOUCH
!8 !9 @0
@6
@7
@8
#0
@9
#1 #2
$2 $3
A
A’
C1
CLICK
36
T
37
S
39
F1
41
R
G1
43
L
D2
50
M
E2
52
H
42 44
A1
45
L
B1
47
M
C2
48
H
51
F2
L
53
G2
H
5554 56
A2
57
L
D3
62
H
B2
59
M
L
C3
60
M
H
58 61
C
1
63
R
1
E3
64
F3
65
R
6
D1
38
E1
40 46 49
CHORD
dim
mM
6
7
augsus4
119
513
1
REC
2
REC
3
REC
4
REC
5
REC
6
REC
7
REC
8
REC
TRANSPOSE REGIST-
RATION TEMPO M
BACK NEXT
KEYBOARDSTART/STOP
E
AS
NAVI
GA
001 Gran
d
qe
#3 #4 #5 #6 #7 #8 #9
!4
!3
!2
!5 !6 !7
$0
yi
u
r
o!0
!1
t
w
@1 @2 @3 @4 @5
$1
$4
A
A’

PSR-550
5
● Rear Panel
$5 [PHONES/OUTPUT] jack
$6 [FOOT SWITCH] jack
$7 [TO HOST] connector
$8 [HOST SELECT] switch
$9 [MIDI IN], [MIDI OUT] connectors
%0 [DC IN 10–12V] jack
$7 $8 $9 $6 $5 %0
qPower switch ([STANDBY/ON])
w[MASTER VOLUME] dial
e[DEMO] button
r[RECORD] button
t[DIRECT ACCESS] button
y[DSP] button
u[FAST/SLOW] button
i[TOUCH] button
o[SUSTAIN] button
!0 [HARMONY/ECHO] button
!1 [BACK] button, [NEXT] button
!2 LCD display
!3 [VOICE CHANGE] button, [MIXER] button
!4 [TRACK 1–16] buttons
!5 [SONG] button
!6 [STYLE] button
!7 [MUSIC DATABASE] button
!8 [VOICE L] button
!9 [VOICE R1] button
@0 [VOICE R2] button
@1 [ACMP ON/OFF] button
@2 [ACMP/SONG VOLUME] button
@3 [TEMPO/TAP] button
@4 [TRANSPOSE] button
@5 [FUNCTION] button
@6 [PART ON/OFF]
• [VOICE L] button
• [VOICE R1] button
• [VOICE R2] button
@7 Number buttons [1]–[0], [–/NO], [+/YES]
@8 [EXIT] button
@9 Data dial
#0 [DISK LOAD] button
#1 [DISK SAVE] button
#2 [DISK UTILITY] button
#3 [SYNC STOP] button
#4 [SYNC START] button
#5 [START/STOP] button
#6 [INTRO] button
#7 [MAIN/AUTO FILL A] button
#8 [MAIN/AUTO FILL B] button
#9 [ENDING/rit.] button
$0 [REGISTRATION MEMORY] buttons
$1 [ONE TOUCH SETTING] buttons
$2 [MULTI PAD] buttons
$3 Disk Drive
$4 [PITCH BEND] wheel

PSR-550
6
■ CIRCUIT BOARD LAYOUT &WIRING
Speaker
(Woofer-L)
L50
Speaker
(Tweeter-L)
W-STB
W-ANAW-DMV
Speaker
(Woofer-R)
W-PNS
W-PNL
380
L40
W-MID
Speaker
(Tweeter-R) W-PND 350
DM
MKS5MK-H MK-L
● Lower case side
● Upper case side
AM
390
W-PITW-MVR
Caution : Be sure to attach the removed filament tape just as it was before removal.

PSR-550
7
● Upper case side
390 370 360 W-LCD
W-EP2 W-ENC W-EP2 W-MVR W-PIT
AM
PN 1/5
PN 2/5
PN 4/5 PN 5/5
PN 3/5
Speaker
(Tweeter-R) Speaker (Tweeter-L)
W-STB390380W-PNL
FDD
W-PNS
W-PND
350 –MKB MKS5-CN1 *2 *1 DM-CN180 *2 *1 6P (V381860)
360 –LCV DM-CN960 *1 PN 1/5-CN102 *1 2P (V381920)
370 V4468500 FDV DM-CN950 *1 FDD-CN2 *1 3P
380 V3819400 FDD DM-CN850 *1 FDD-CN1 *1 34P
390 –BLT DM-CN999 *1 Back Light 6P (V705780)
L40 –SPW AM-CN480 *1 Speaker (Wo) 4P (V381950)
L50 –BAT AM-CN510 *1 Battery 2P (V705790)
W-ANA –ANA AM-CN100 DM-CN250 *1 4P (V381820)
W-DMV –DMV AM-CN530 DM-CN920 *1 5P (V381840)
W-EP2 –EP2 AM-J411,J412 Speaker (Tw-L) L=160 (V457700)
W-EP2 –EP2 AM-J421,J422 Speaker (Tw-R) L=160 (V457700)
W-MID –MID AM-CN800 DM-CN170 *1 7P (V381870)
W-ENC –ENC PN 2/5-CN602 PN 1/5-CN502 *1 3P (V381800)
W-LCD –LCD PN 1/5-CN101 DM-CN750 *1 12P (V445890)
W-MVR –MVR PN 4/5-CN801 AM-CN390 *1 5P (V381830)
W-PIT –PIT PN 3/5-CN603 PN 1/5-CN503 *1 3P (V381810)
W-PND –PND PN 1/5-CN301 DM-CN650 *1 8P (V381880)
W-PNL –PNL PN 1/5-CN501 DM-CN550 *1 10P (V381890)
W-PNS –PNS PN 1/5-CN401 DM-CN150 *1 11P (V381900)
W-STB –STB PN 5/5-CN701 AM-CN520 *1 6P (V381850)
*The parts with “–”in “Part No.”are not available as spare parts.
*1 : Edge mark is adjusted to Pin 1 mark ( mark).
Location Part No. Connector Assembly Destination Remarks
* 2 : Be sure to make a correct match when connecting MKS5 (CN1)
and DM (CN180).
Connecting the connectors in the wrong way around may cause
damage to the MKS5 circuit board.
RED BLUE WHITE
● Side view
Back Light Assembly
Back Light Assembly & LCD
390

PSR-550 8
■ BLOCK DIAGRAM
X100
7MHz
CL1
5MHz
X200
33.8688MHz
X800
16MHz
28CA1-8819395
64M
IC230 44P
2,5,6,9,12,
15,16,19
HC74
TR
CN150
9 – 15
CN603
CN602
CN503
CN502
PITCH BEND
DATA DAIL
RE602
VR603
SI[0 – 10]
YAMAHA PSR-550
CN999 BACK LIGHT
Switch 2bit
IC700 16P
TO HOST
HOST SELECT
MIDI
IN OUT
IF
LF501
VR800
12
9
IC370 20P
7
4
SW700
CN530
CN920
158
DC IN
(10-12V)
PHONES/OUTPUT
CN480
5/5
4/5
1/5
3/5
2/5
FOOT SWITCH
4-20,22
29-30,
52-54,
56-60,
62-64,
61-70
RESET
IC190
84
/IC
+5D
1-10,
14-21,
23-30,
32-42
1-3 8,9 2,12
1
2
3
2
5
6
9,12,15
16,19
3,4,7,8,13,
14,17,18
2-15,17-21,
18-21,24-28,
35-38
2-5,7-10,
18-21,
24-28,
35-38
32-35,47,48,50,
51,53,60,61
6
39-46
15
2
/IC
22
/IC
30
2-5,7-10,
18-21,24-27,
35-38,40-43
2-11,15-22,
24-31,34-44
CN510
MKS5
CN1
+5R
IC1 44P
CPU
MK-L MK-H
CN3 CN2 CN4
IC100 112P
IC260 44P
IC200 168P
IC270 28P
IC310 42P IC350 16P IC800 64P IC999 14P IC700 20P
TR998
TR999
IC100 80P IC200 60P
IC300 44P IC330 32P IC500 20P IC600 16P

PSR-550
9
■ DISASSEMBLY PROCEDURE
3. DM Circuit Board, Shield Box U and L
(Time required : About 10 min.)
3-1. Remove the lower case assembly. (See procedure 1)
3-2. Remove the two (2) screws marked [430B] and the
fourteen (14) screws marked [450]. The shield box
U and the DM circuit board can then be removed.
(Fig. 4)
3-3. Remove the three (3) screws marked [420A]. The
shield box L can then be removed. (Fig. 4)
4. Floppy Disk Drive Assembly
(Time required : About 10 min.)
4-1. Remove the lower case assembly. (See procedure 1)
4-2. Remove the DM circuit board and the shield box
U and L. (See procedure 3)
4-3. Remove the four (4) screws marked [460]. The
floppy disk assembly can then be removed. (Fig. 5)
5. AM Circuit Board
(Time required : About 15 min.)
5-1. Remove the lower case assembly. (See procedure 1)
5-2. Remove the DM circuit board and the shield box
U and L. (See procedure 3)
5-3. Remove the eleven (11) screws marked [420B].
TheAM circuit board can then be removed. (Fig. 5)
[430A] :Bind Head Tapping Screw-P 3.0X12 MFZN2Y (EP600300)
[440A] :Bind Head Tapping Screw-P 3.0X25 MFZN2Y (VK228100)
(Fig.1)
2. SpringTerminal
(Time required : About 10 min.)
2-1. Remove the lower case assembly. (See procedure 1)
2-2. Remove the BAT connector assembly (red/black)
soldered to the spring terminal (+)/(-). (Fig. 2)
2-3. Remove the battery cover assembly. (Fig. 1)
2-4. Remove the spring terminal by releasing hooks
(2 locations for each). (Fig. 3)
1. Lower Case Assembly
(Time required : About 5 min.)
1-1. Remove the fourteen (14) screws marked [430A]
and the four (4) screws marked [440A]. The lower
case assembly can then be removed. (Fig. 1)
[430A] [430A] [430A]
[430A][430A]
[440A] [440A]
[430A] Lower Case Assembly
Battery Cover Assembly
(Fig.3)
Spring Terminal
Hook
Hook
(Fig.2)
Lower Case
Assembly
BAT Connector
Assembly (Black) BAT Connector Assembly (Red)

PSR-550
10
[30] : Bind Head Tapping Screw-P 3.0X8 MFZN2Y (EP600280)
[420] : Bind Head Tapping Screw-P 3.0X8 MFZN2Y (EP600280)
[430B] : Bind Head Tapping Screw-P 3.0X12 MFZN2Y (EP600300)
[440B] : Bind Head Tapping Screw-P 3.0X25 MFZN2Y (VK228100)
[450] : Bind Head Tapping Screw-B 3.0X8 MFZN2Y (EP600250)
[L30] : Bind Head Tapping Screw-P 4.0X8 MFZN2BL (VB931600)
(Fig.4)
[420B] : Bind Head Tapping Screw-P 3.0X8 MFZN2Y (EP600280)
[460] : Sems Pan Head Screw 3.0X10 MFZN2Y (V5115200)
(Fig.5)
[420H] [450] [420A] [450] [420A] [450]
[L30]
[440B] [430B] [450] [430B] [30] [30] [440B]
[420H]X2
Keyboard
Assembly
Speaker
(Tweeter)
Speaker
(Tweeter)
Speaker
(Woofer) Speaker
(Woofer)
Shield
Box U
[L30]
MKS5
[420B] [460] [420B] [420B]
[420B]
[460]
DM AM
FDD
AM
Shield Box L