BOSSCO Dr. Rhytm DR-550 MK II Operating and maintenance manual

APRIL.1992 DR-550mk2
obqss DR-550MKn
Dr Rhythm
ERRATA &SUPPLEMENT isattached at the end of the page, it
DDDDDDDDDDDDDDDDDD
TABLE OF CONTENTS Page
SPECIFICATIONS 1
EXPLODED VIEW 2
DR-550mk2 DISASSEMBLY PROCEDURE DR —550mk2 /}£.& 3
AND PRECAUTIONS
PARTS LIST
BLOCK DIAGRAM
CIRCUIT DESCRIPTION
CIRCUIT BOARD(MAIN BOARD)
CIRCUIT DIAGRAM(MAIN BOARD)
IDENTIFYING VERSION NUMBER
SETTING FACTORY PRESETS
DATA SAVE AND LOAD
TEST MODE
TROUBLESHOOTING
1C DATA
APPENDIX
IJ 7s h4
y005
mam 5
«KH(*-f y&fa) 6
7
A-va 8
7rn u-yufey 8
8
h:E— K9
h7^ 10
ICx-* 11
nm 12
SERVICE NOTES]
First Edition SPECIFICATIONS/tttH
•Number of Tones/ :91
•Mximum Polyphony/ :12
•Memory Capacity/ U—WS :64 Preset Patterns
64 Programmable Patterns
(Configuration:Scale 1to 4, Last Step 1to 16)
8Songs
(Max. 160 bars/Song ,1280 bars by using Song Chain function)
(** 160 /j\g& /ft ,vyy*xdi1280 /j\as©a^3iiipriii
)
•Tempo
•External Data Storage/ >€U-
•External Sync/^^3 v'y$ $$!§
•Output Level/ tht)
•Noise Level/ JdX
•Power Source/®}®
•Battery Life/
•Current Draw/ g
•Dimensions
•Weight
•Accessories
•Options
J=40 to 250
Audio Cassette Tape
MIDI
Max. 6.5 Vp_p (L or R)
Max. 0.35 Vp_p (Tape Save)
Less than -82.5 dBm (L or R)
DC 9V,SUM-3 Battery x6or AC Adaptor (Option)
Approx. 9hrs. (manganese), 23hrs. (alkaline type)
im9$1® (-7 yn),23 n$y
|NOTE |These figures will vary depending on the actual conditions of use.
[
si mmmmm
90mA
188(W) x157(D) x41 (H)mm
7-7/1 6(W) x6-3/1 6(D) x1-5/8(H) inches
51 0g/1 lb. 2oz. (including batteries)
Dry cell Battery SUM-3S 1.5V (x6pcs)
INOTE 1The above parts(Dry cell Battery SUM-3S) does not supply as replacement
parts, because it is goods.
HOT] (Dry cell Battery SUM-3S) mmMUdit L
m
Owner’s Manual Set (Japanese) :PNo.260551 63
Owner’s Manual Set (English) :PNo.260551 64
AC Adaptor BOSS PSA Series
—Display Cover
Rubber Switch
(22495241)
Top Case Ass’y
[FRONT PANEL]
(22045395)
LCD
RCD-1-013R
(15029506)
LED(red)
GL8PR25
(1 5029324)
Knob
(22485211)
TM-3 VR Spacer
(2216035300)
Pot.
RK14K1230 50kB x2
(13279966)
(22045431)
Switch Jack Jack
SSSU11
(13159168)
YKB21 -5130
(13449433)
YKB21 -5129
(13449428)
Bottom Case Ass’y
(22045428)
17059647 Printed in Japan B0BE (DP) 1Copyright ©1992 by ROLAND CORPORATION

DR-550mk2 APRIL.1992
EXPLODED VIEW/ ftf&m
No. -PARTS NAME--PARTS No.
-
©Knob 2248521
1
(2) VR Spacer 2216035300
(3) Display Cover 22045395
@Top Case Assy :22045431
|NOTEl Before removing or installing the shield cover, please refer to ”DR-550mk2 disassembly procedure and precautions”.
(p.3)
[WW\ V-Jimz, TDR- 550mk2 (p.3)
1NOTE |We do not supply the Top Case separately.
non Top Cas
®Rubber Switch :22495241
©LCD RCD-1-013R :15029506
®Rubber Connector for LCD :23365653
|e1©Main Board Assy :7316903000
|NOTE 1Replacement Main Board Assy consists of the following 2PCBs.
1jfe |Main Board Assy (T TIB© 2t'o
Main Board Assy (1/2) (pcb 2292586803 1/2)
Main Board Assy (2/2) (pcb 2292586803 2/2)
(§) Bottom Cas 22045427
®Battery Box Assy :23425822
(Q) Terminal Spring (+/-) :23455182
®Terminal Spring (+):23455180
®Terminal Spring (-) :23455181
®Battery Case 22015963
®Battery Cover :2206521
0
©Shield Cover 22255299
[SCREW]
(a) 2.6 x6mm Binding P-tight FeNi
Black
2

Disassembly procedure and
precautions
©How to remove/install the Shield Cover
1.To remove the Shield Cover
a) Remove the solder from “•:Soldering point” (refer to
“EXPLODED VIEW”, p.2).
b) Remove the main board (1/2), (2/2), LCD and rubber switch.
[NOTE |Refer to “Precautions when removing the main board
(1/2)”, p.3)
c) Use asoldering iron to melt location “”, and remove the
Shield Cover from the top case.
|NOTE |At this time, be careful not to melt any other areas of
resin.
i.
a) “#:Soldering point”(^)SEl (P. 2)#M) ©^EB-S-IKo TT$l'o
b) Main Board (1/2), (2/2), LCD, diU •XT yUT^^'o
\)1 “MAIN BOARD(l/2) £<D&M "(P.3) £#MLT
~F $I'o )
c) ^"©8B#(TBH&M)£n h
Kt^lTT^i'o
\)±m\
l'o
2. To install the Shield Cover
a) Use asoldering iron to melt location “and install the Shield
Cover in the top case.
|NOTE |At this time, be careful not to melt any other areas of
resin.
b) Install the main board, (1/2), (2/2), LCD and rubber switch.
|NOTE |Refer to “To install the LCD”, p.3)
c) Solder the “#:Soldering point”(refer to “EXPLODED VIEW”,
p.2).
2.
a) “”(D$m (T0#flR )
W
Uv~)l h
non c
©
b#, ^i'^? iz .®mltt
$
l'o
b) Main Board (1/2), (2/2), LCD, dA•Xd’y $l'o
la M\ “LCD (DM <9 "(P.3) LT<fc*$l'o )
c) “#:Soldering point”( (P. 2) )3r^EBft 1} LTT$l'o
V
DR-550mk2
©Precautions when removing the main board
(1/2)
The LCD and rubber connectors are not fastened to the main board
(1/2) so when you remove the main board (1/2), be sure to remove the
LCD and rubber connectors from the main board (1/2).
©To install the LCD
1. Insert the LCD into the frame. (Refer to Fig. a.)
©MAIN BOARD (1/2)
LCD, dU •MAIN BOARD (1/2)
SftTl'S-tivMnN MAIN BOARD (1/2) fcffibftLfcB#
li, MAIN BOARD (1/2) ±*'bLCD, 9-
^ItT^l'o
©LCD
l.LCD^#^(iJ6iAAT'T$l'o (Ela#M)
Fig.a (0 a)
2. d\L •
(0b#M)
LCD td'-U •&—t©ScK",
tMAIN BOARD (1/2) iOftfri:, J&<ft*F Ll'«fc
SfcffiftLTTSi'o
Fig.b (0 b)
2. While pressing the rubber connector to the right, insert it into the
slot. (Refer to Fig. b.) At this time, be careful that no dirt comes
between the LCD and the rubber connector, or between the rubber
connector and the main board (1/2).
3. Install the main board (1/2) firmly in place. 3.MAIN BOARD (1/2) LoftftTTc? l'o
4. Use “Test Mode (p.9) /[2] LCD Check” to confirm that the LCD 4. LCD Z)<IE L<JK *9 ft S> fa tzfi't' O“fXf •X- K
has been correctly installed. (P. 9) / [2] LCD /TffifiiS LTT $l'o
3

PARTS LIST//\°-'7 'JXF
SAFETY PRECAUTIONS:
The parts marked Ahave
safety-related characteristics.
Use only listed parts for
replacement.
:
zEjwrt'Tt'&so;!.
±mfem%T-o< entcb
(DZ'to
38j|©85li.
#^i^l-©gBn
D
0ttfi6b4'l '<fc
OICLTTSI'.
1CONSIDERATIONS ON PARTS ORDERING ]
When ordering any parts listed In the parts list, please specify the following Items In the order sheet.
QTY PARTNUMBER DESCRIPTION MODEL NUMBER
Ex. 10 22575241 Sharp key C-20/50
15 2247017300 Knob (orange) DAC-15D
Failure to completely fill the above Items with correct number and description will result In delayed or
even undelivered replacement.
i&TTK®4li IBficSBA LTT£(.'<> (WMil&O
#j) 10 22575241 Sharp key C-20/50
15 2247017300 Knob (orange) DAC-1 5D
fcLKAiift. £4'*' ofc IK <Jtto
to
MB(1/2) -> MAIN BOARD ASSY (1/2)(pcb 2292586803 1/2)
MB(2/2) -> MAIN BOARD ASSY (2/2)(pcb 2292586803 2/2)
CASING/ (T-Z
22045428
Top Case Assy
INOTE! Replacement Top Case Assy consists of the following 2parts.
We do not supply the Top Case separately.
|;j ft ICase Assy ii, TIB® 2SRStSifiX ATlT To
Top Case ®*©#8&l**!5 £&«*/<>
******** Top Case
22255299 Shield Cover
Bottom Case Assy
INOTE |Replacement Bottom Case Assy consists of the following 3parts.
IaIt 1Bottom Case Assy IT. T12© 3Sft £To
22045427 Bottom Case
22065210 Battery Cover
23425822 Battery Box Assy
INOTE |Replacement Battery Box Assy consists of the following 4parts.
IaM. IBattery Box Assy 14, TIB© 4Aft £To
22015963 Battery Case
23455182 Terminal Spring (+/-)
23455180 Terminal Spring (+)
23455181 Terminal Spring (-)
Display Cover
KNOB,BUTTON/ 7?/, V
22485211 Knob
JACK,SOCKET/ yr-j (7 -Uhr-j h
13429642 M-S2-3P
13449428 YKB21-5129
13449133 HLJ052 1-01-1 10
13449433 YKB21-5130
13449720 HEC-2305-0 1-250
DIN
monaural
monaural
MIDI IN
TAPE SAVE/ LOAD
OUTPUT L,R
PHONES
For Using AC adaptor
SWITCH/ XT
13159168
2495241
SSSU11
Rubber Switch
Power Switch
DISPLAY UNIT/BUTCi:
PCB ASSY/8$g:rEfiici5i
m7316903000 Main Board Assy
INOTE [Replacement Main Board Assy consists of the following 2PCBs.
IWWIfrfitITIj Main Board Assy 14, TIB® 2£ft £To
Main Board Assy (1/2) (pcb 2292586803 1/2)
Main Board Assy (2/2) (pcb 2292586803 2/2)
15199803
15239138
15209372
15279521
15259886N0
15259883
15259720T0
15289701
15289107
15199216
15289401
15289124
UPD753 16GF-237-3B9
MB87604PF-G-BND
MB838000-20P-G-3B5
SRM2264LM-10T
UPD74HCU04G-E2
TC7S00F TE85L
TC74HC74F-T2
UPD6376GS
M5218FP SOP
LM2931Z-5.0
SC17710YDA T1
PC-400
(Flat/Taping)
(Flat/ Taping)
(Chip/ Taping)
(Flat)
(Flat)
(Flat/Taping)
(Chip/ Taping)
(Flat/ Taping)
Mask CPU
Gate Array
8M MASK ROM (Wave Rom)
CMOS S-RAM
H-CMOS Hex Inverter
1Gate CMOS NAND
CMOS D-Type Flip Flop
D/A Converter
Op.Amp
+5V Voltage Regulator
+3V Voltage Regulator
Photo Coupler (Opto-Isolator)
IC1 on MB (1/2)
IC2 on MB (1/2)
IC3 on MB (1/2)
IC5 on MB (1/2)
IC6 on MB (1/2)
IC4 on MB (1/2)
IC8 on MB (1/2)
IC103 on MB (2/2)
IC104,IC105 on MB (2/2)
IC101 on MB (2/2)
IC102 on MB (2/2)
IC7 on MB (1/2)
TRANSISTOR/ 177/7/-
2SC2412KR T-146 (Chip/ Taping) Q1,Q2,Q3 on MB (1/2)
Q101 on MB (2/2)
DR-550mk2 APRIL.1992
4

APRIL.1992 DR-550mk2
BLOCK DIAGRAM/ 9H
CIRCUIT DESCRIPTION
The LSI (IC2) has akey role in the DR- 550mk2 circuit.
The main tasks of IC2 are as follows.
•Supply of master clock
•Access to memories (RAM and ROM)
•Envelope operation and pan operation
•Output of digital operation results to DAC (IC103)
•Receiving MIDI information and Transmitting to the CPU.
DR-55Omk2©0i&li# X9ALSI (IC2) UoTffijff L
IC2©±tt|S$gtt> TfBOififJ'Cfo
•-?7>9 —•9ay? ©$#&
•RAMfc<fcO'ROM'\©7?-t?X
•—7\
•ti&M&tltz-r :
J9>Kt —9DAC ^(±1^7 i~ 6
•MIDI CPU
5

DR-550mk2 APRIL.1992
NOTE
Replacement Main Board Assy consists of the following 2PCBs,
Main Board Assy TIB© 2To
Main Board Assy (1/2) (pcb 2292586803 1/2)
Main Board Assy (2/2) (pcb 2292586803 2/2)
WOtl 'GNflOS 'fi-

APRIL.1992 DR-550mk2
CIRCUIT DIAGRAM/Wm(> A
<h <b
ice
UPD74HCU04G
LCD (36)
(33)
(1) (32)
GUIDE
K»
PAD 12 |PAD 11 IPAD 10 IPAD 9
i-o On A-O On i-O 0-1 A-O
ACCENT
K>
STOP/CQNT |START
A-O
COM3
I
COMO IC1
CPU
UP075316
BIAS
VLCO
VLCI
VLC2
D3-D17 :DAN202K T-96
+5V
(DIGITAL)
+5V
(ANALOG)
+9V
(ANALOG)
DIGITAL
GND
ANALOG
GND BUCK UP
+5V
t
+5Va
t
+9V
tizt-a
(@u|
XT2 Y^. (NC)
m26 58 m
—Wn
n40
&
JK2
IC2
MB076O4PF-G-BND
17 L_ nJ
24 1
431
630
a2
63
a29
11 28
74
22 25
lo 23
21 ^26
"23 ^27
9^5
12 ^6
13 27
14 ^B
15 ^9
19 ^10
IB 11
16 ^12
RA2 1Kx4
MNR34J5A1C
31 B,
12
121
32 7wv 20
33 6 3 '19
34 84IB
35 Bi>17
36 5415
37 63^14
36 72'_13
HBB3BOOO-2QP-6-3B5 26
2
r23
<* 21
24
25
3
4
5
6
r7
B
9
<10
<
19
IB
17
16
15
r- 13
12
11
22
27
[BuJ CB
100/6.3
** IC16
1*~t 25V0.
1
28 ^
SRM2264LM-10T
IC7
PC-400 Si
568B6 8N101 JK101
‘\
°~r\y
IoCO
A3_T .SCI7710YQA
T2M1Vi—Ml1|_
r-4 11
d1*1
MAIN BOARD (1/2) MAIN BOARD (2/2)
V
Knn
IN
oc w
M-
TAPE
WE
PHONES
7

DR-550mk2 APRIL.1992
IDENTIFYING VERSION NUMBER
While simultaneously pressing the [TEMPO] button and the
[/+1] button, turn the power on. The following display
will appear.
Example :for version number 1.23
To exit the version display, press the [ACC] button.
A'-y 3yovkwfiik
[TEMPO] >i [/+1] t:tt, WM&A
tltto
#ij :Version Number 1.23
'<-•7 3[ACC] A?
P1.13
1/ 11i
SETTING FACTORY PRESETS
p|NOTE |
Before you initialize, be sure to save the user’s data.
To save user’s data, refer to “DATA SAVE AND LOAD" (p.8).
777hU—~f Viz-y h(DExaEJjH;
H^I
"
Tx>17fXtail^ •f-7Z&&LXT
c? 1'o
•f-
7
(D&ftJT'&lt, V<dJj
m”(p. 8) miLTT^'-'o
DATA SAVE AND LOAD
|NOTE IThe tape recorder you use must meet the following
conditions.
1.It must have arecording monitor.
2. The recording level must be adjustable.
We recommend that you use atape recorder designed
for storing computer data.
1.Save
NOTE
Use “2. Verify” to confirm that the data has been correctly
(D Connect the TAPE SAVE/LOAD of the DR -550mk2to the
LINE IN of the tape recorder.
©While pressing the [SHIFT] button, press [9] on the keypad.
(3) Start recording on the tape recorder.
(?) After several seconds, press the [START] button.
*When you press the [START] button, apilot signal (a steady
tone) will be output for about five seconds. Adjust the
recording level of the pilot tone to about -103VU.
*To abort the save operation, press the [STOP/CONT] button.
(5) While saving, the display will show “SAVE”, and the tempo
indicator will light.
(D When saving is completed and the tempo indicator goes out,
stop recording on the tape recorder.
While simultaneously pressing the [-1/-*] button and the
[+1/M button, turn the power on. The following display
will appear.
[-i/<| *'7>i [/+l] #7 y*m^WLtz££,
£to
1Ml
j. mm
Press the [START] button. The following display will appear,
the data will be initialized, and the normal display will
reappear.
To return to the normal display without initializing, press the
[STOP/CONT] button.
[START] *'7
^yt7fXU> tto
[STOP/CONT] *’7 i f ~•> *ff
to
c
L1M1
in
M
2. Verify
®Connect the TAPE SAVE/LOAD of the DR -550mk2 to the
LINE OUT of the tape recorder.
(2) Rewind the tape on which you saved the data, and stop it abit
before the playback sound changes from the steady tone to
the warble.
(3) While pressing the [SHIFT] button, press [10] on the keypad.
©Start playback on the tape recorder.
(D Press the [START] button.
*Press the [START] button before the tape playback sound
changes from the steady tone to the warble.
*To abort the verify operation, press the [STOP/CONT]
button.
(6) While verifying data, the tempo indicator will blink.
(7) If the data has been saved correctly, the LCD will show "V
Gd”. If an error occurs, the LCD will show "V Er”, and verify
will be aborted. In this case, adjust the tape playback level
and try again. If an error occurs no matter how many times
you try, adjust the recording level and save the data once
again.
3. Load
©Connect the TAPE SAVE/LOAD of the DR -550mk2 to the
LINE OUT of the tape recorder.
©Rewind the tape on which you saved the data, and stop it abit
before the playback sound changes from the steady tone to
the warble.
©While pressing the [SHIFT] button, press [1 1] on the keypad.
@Start playback on the tape recorder.
©Press the [START] button.
*Press the [START] button before the tape playback sound
changes from the steady tone to the warble.
*To abort the load operation, press the [STOP/CONT] button.
©While loading data, the tempo indicator will blink.
©If the data has been loaded correctly, the LCD will show "L
Gd”. If an error occurs, the LCD will show "L Er”, and load will
be aborted. In this case, adjust the tape playback level and try
again.
1.
2.
7’ny? hi LT(i. p>t°^-7 -fflf -7 •Dp-7"-
l.-fe —zf
Hiil I
'
f-7£fz-7L/ciI£\
t>\ >&t “2. ^U77-T ”£lT&oT$ii8LTT£(.\>
©DR-550mk2© TAPE SAVE/ LOAD if- 7°* Up-7-
©LINE
©[SHIFT] K© [9]
©•f-7p•l/ra-y-Ofiflt***- hL£i~o
®W&& [START] o
*[START] hff^f (tf-
il'7#)
/<? p"j h^©!!# ~-3VUfMJSl^ll®5 L
X<[STOP/CONT] tf'7>£
©f—7©-te— -/tpa.T'f 7.7°UTII “SAVE” tl.f >
$•T>7
f
-7-&&& Ltto
1/3-^-©®#** b"J -fLtiTo
2. ^V774
®DR-550mk2 ©TAPE SAVE/LOAD ix- 7° •hn-A©
LINE OUT ZjgffiLtto
©f-7©m7f/><
“t0-” frt, “fcf pt° p”h"j Xltto
©[SHIFT] #7 K© [10]
©f-7 •i
©[START] L£to
*t-7©?I£Wj&< “t°—”“t°Pt°n” izBzfr&wjlz
[START] #77LX<tz £lV[STOP/CONT] f7
yZWltto
©7r'f'P&s’T'y&f >7f-7-/>9£M L££~o
©f—7jWEU< -fe— 7'$tlT‘V'/cJ#-o‘(±> LCD lz “V Gd” i
&ipXx5-fi<%&Lt:JM&ltLCDlz “V Er” ifeLT, A
V7rJ%tp±l£to
cvm&tes mix, ^iw^
JP<9itLT<
P)MLX
AXt!-^^-ALULX< /c&Oo
3. -K
©DR-550mk2 ©TAPE SAVE/LOAD if—7° •l/P-f-©
line
©t-?*-b -7' Ltzf- “i^LT.r- f©H^#
“t0-” “t°Pt°p” ld^t?Sd>L^HiJTr7 h
©[SHIFT] K© [11]
©f-f* h^firt-fo
©[START] “t°-” “t°Pt°P”
[START] ffLT</f $O0
[STOP/CONT]
©f— ^©p— f>f° •f>yf—
©f-^TEL< p- f> XfUfJC “L Gd”
i^7F$tl^fo X^H'i: “L Er” ig
/t:IT> p- K£thui:L3:-fo
f-7p©S^U/<^»L-r.
'P'QUlXi
8

APRIL.1992
TEST MODE 7Xht— K
©Required items
•Oscilloscope, monitor speaker (MA- 12C, etc.), oscillator,
measurement device (see Fig. 1).
Fig.1 (Ell)
•oX3-A— ^•Xtf -A—(MA- 12C ^),
^/Pin to Pin Cable
-45 cJBtzuo
Pin Jack
©To enter test mode
While simultaneously pressing the [LEVEL] button and the [/+!]
button, turn the power on. The LCD will show “TST”, and you will
enter test mode. Then, press anumerical key [1]— [6] to execute
each test.
Hnote 1——
If atest results in NG, refer to “Troubleshooting”(p.10).
Numerical key/Test item
[1 ]Key check
[2] LCD check
[3] RAM check
[4] Tape save check
[5] Tape load check
©To exit test mode
Press the [ACC] button to initialize and return to the normal
display.
[1]
Key check
#This test checks whether each key is functioning.
1
.
Make connections as follows.
L/MONO
DR-550mk2
2. The instant you enter this test, the LED will flash. Then, the
LCD will show “KY”.
3. When you press each key, aclick will sound. Press all
keys in any order.
4. If normal, the LED will go out, and the LCD will show“OK”.
-NOTE |
If the “OK” display does not appear, you will have to turn the
power off and reenter test mode to perform other tests.
©[LEVEL] *'£>£[/+1] tLtz ££,'
tltto
t&t, LCD IZ. TTSTJ h-A- Kt-A^Ao
c©|£, [i ]~[6] ©»¥*--
AamI—
§fx >^'”(P.10)
—
[1] *-*AxvX
[2] LCDfx7^
[3] RAMfxy?
[4] f-y*t-y*fx^
[5] r-7«o- K*A xv?
©=5-7s VO.MUX
[ACC] rK 9
[1]
i. Tis©£9«ii§cL;£-ro
MA- 12C or equivalent
MA-12CH
2. :®fx 7^i;AoW^ led L£ Ao
ALT> LCD Id fKYJ t^tZtltto
3. LTl'< is 9') vV
MlZ.£X<D*-&Pto
4. LED^AT, LCDICTOKJ t^Zfttto
-at |
roKJ mfc&teiDll#, ffljofx E£Ar*5^i;:(i, —
SJgAX h«A- KfLA&t^&^-tt/U
[2]
LCD check
#This test checks whether the LCD is normal.
1
.
The instant you enter this test, all segments of the LCD will
be displayed. (Fig. a) The LED will also light.
[2]
LCDAx-yS?
•LCD^TE^-Cfe^ttx 7^Uto
1.
:0fx yLCD©£-fcrXV >b/^7F
$tit to (El a#M)LED k.ttr Ltto
fSONG REPEAT MIDI SYNC
SCALE
PATTERN
ABCD
INSERT
DELETE
Fig. a(El a) SONG EDIT MEASUREPAD EDIT PATTERN VOICE
PATTERN EDIT MIDI SETUP TEMPO LEVEL
ann ..abiQO .. 60601wo
bOO cdiOO khi&&U
2. Press the [START] button, and half the LCD segments will
be displayed. (Fig. b)
DR-550mk2
2. [START] t£>t,LCD ©^-tr >h$tl
tto (El b)
|PAD BANK IAiCETT
Fig. b(Elb)
PATTERN ••••
SONG EDIT
PATTERN EDIT
33
II
3. Press the [STOP/CONT] button and all LCD segments will
be displayed once again.
4. Press the [ACC] button to exit the test.
5. If normal, the LED will go out, and the LCD will show“OK”.
PATTERN VOICE
II ULH/L I
DIL U2lLl ls k
3. [STOP/CONT] tt <t, MLCD<D±±X/ >h
4. [ACC]tt
5. LED^AT, LCDII TOKJ
tltt
[3]
RAM check
#This test checks whether RAM is normal.
1. The instant you enter this test, the LED will light. The LCD
will show “RA”. Checking is performed automatically.
2. If the results are normal, the LED will go out, the LCD will
show “OK", and you will exit the test. If amalfunction is
found, the LCD will show “NG”.
[4]
Tape save check
1
.
Make connections as follows.
2. Check that a3.2 kHz 0.35Vp-p sawtooth wave is being
output.
Oscilloscope settings for this test: 0.1 V/div
0.1 msec/div
3. To exit the test, press the [STOP/CONT] button.
[5]
Tape load check
1
.
Make connections as follows.
TAPE SAVE/ LOAD
DR- 550mk2
[3] RAMAxy^
#RAM^IESTrab^^^x y7Ltto
1. c©^x •;/?{;: AofcMK, LEDj^iTL^-fo LCD A
TRAj
SffijWl-Ax V?Ltto
2. lEIgtim&tebrt, LED^mr> LCDId TOKJ ch^7F$
ti, Ax y7£t&lf£to
lcdic tngj tmtzntt„
[4] x—X•—A*AXy0
i. TIB©J:-9l-SieL^^o
Oscilloscope
2. 3.2kHz, 0.35Vp-p©£g$^iEA$tl£Cd: ;£\ BBt&o
$iJ£B#©A'>a©f££: 0.1 V/div
0.1 msec/d iv
3. Ax>y ?6£%ti, [STOP/CONT] L
£to
[5] x—X*~K•Axy0
i. TIE© 9tLgcirc L£to
Pin Cable n<E~x~l
Oscillator
2. The instant you enter this test, the LED will light.
3. When you input a3.2 kHz 0.35Vp-p signal, the LCD will
show “OK”, the LED will go out, and you will exit this test.
4. You will not be able to exit this test until the correct signal
is input. To abort the test, press the [STOP/CONT] button.
-
|NOTE I
At this time, the LCD will show “L Er”, but you can select
another test by pressing another numeric key. Rarely, the
program may hang up when you press the [STOP/CONT]
button. If this occurs, turn the power off.
2. :©fx^ irA
o
tzMffl !A led t&tt L£to
3. 3.2KHz, 0.35Vp-p ©£g$£IEL<AAt' 6<!:> LCD iZ
TOKJ LED^AT^©Ax V
to
4. (B'^'IEL <AA$till'd:, IE LWlA^'AA£ 1
Tfx yyfrtbifct
AX-y ?tz ©t%(i, [STOP/CONT] ^>tw L£
to
-at |——
C©B$, LCDJC TLErJ tltttf*
(i'> fil2©AX
[STOP/CONT] tK ^LAt§,£niZ^tit ZZ.tfrh'O
£to
[6]
ROM check
#This test checks whether the ROM can be correctly read.
1.The instant you enter this test, the LED will light. Checking
proceeds automatically.
2. If the result is normal, the LED will go out, the LCD will
show “OK”, and you will exit the test. If amalfunction is
detected, the LCD will show “NG”.
[6] ROM txy<P
•ROM^JEL<^6£^Ax<y ?L£tc
1. C©^xv^lLAoA^lL, LED^iTLlElJ'o
ga&Wi-f-x V?L£to
2. LED^AA, LCDII TOKJ
tl, Ax VV^fettto
lcd ic tngj tBitzntto

DR-550mk2 APRIL.1992
TROUBLESHOOTING/
If atest results in N.G., refer to the “Troubleshooting” (P.90)section N.G.©:i|§'n„ “$$$£^§9 HU ”(P.90) 3r#BSlf''5>/r\ £
on the Owner’s Manual, or check the following points while referring fc{± 01^11] LT, TIE© Cl
to the circuit diagram. •(frolic? Tl'-S/no
•Is there asignal? •IC^©fft$a1II^{iIES/>''o
•Is the power supply for the ICs etc. correct? •9a-y 9(± %Tl
•Is there aclock? etc.
Check the area of main board (1/2) IC1 and IC2.
MAIN BOARD (1/2) IC1, IC2
Check the using tape recoder, tape and connecting cable.
10

APRIL.1992 DR-550mk2
ICDATA/ICx-^ MB1 -*Main Board (1/2) (pcb 2292586803 1/2)
MB2-*Main Board (2/2) (pcb 2292586803 2/2)
MASK CPU (IC1 on MB1)
UPD7531 6GF- 237- 3B9
(15199803)
64 41
65
80
40
iiiiiiiiiiiiiii(nnnn
124
(TOP VIEW)
F— 25
1S12 21 COMO 41 P03 61 P61
2SI 322 COM1 42 P10 62 P62
3S14 23 COM2 43 P11 63 P63
4SI 524 COM3 44 P12 64 P70
5SI 625 BIAS 45 PI 365 P71
6SI 726 VLCO 46 P20 66 P72
7SI 827 VLC1 47 P21 67 P73
8S19 28 VLC2 48 P22 68 RESET
9S20 29 P40 49 P23 69 SO
10 S21 30 P41 50 P30 70 SI
11 S22 31 P42 51 P31 71 S2
12 S23 32 P43 52 P32 72 S3
13 S24 33 VSS 53 P33 73 S4
14 S25 34 P50 54 VDD 74 S5
15 S26 35 P51 55 XT1 75 S6
16 S27 36 P52 56 XT2 76 S7
17 S28 37 P53 57 N.C. 77 S8
18 S29 38 POO 58 XI 78 S9
19 S30 39 SCK 59 X2 79 S10
20 S31 40 SBO 60 P60 80 ,111
Gate Array (IC2 on MB2)
MB87604PF-G-BND
(15239138)
(TOP VIEW)
2INPUT NAND GATE (IC4 on MB1)
TC7S00F
(15259883)
5VDD
4OUT X
PHOTO COUPLER (IC7 on MB1)
PC- 400 (OPTO- ISOLATOR)
(15289124)
2CATHODE
ANODE
(TOP VIEW)
D/A Converter
pPD6376GS
(15289701)
(IC103 on MB2) +5V Voltage
LM2931 Z-5.0
(15199216)
Regulator (IC1 01 on MB2) +3V Voltage Regulator (IC102 on MB2)
SCI771 OYDA
(15289401)
TRANSISTOR (Q1 -3 on MB1)
(Q101 on MB2)
2SC2412KR (NPN type)
(15319101)
fs SEL EECLK
D.GND EESI
NC EELRSEL/SI
D.VDD ELRCK
A.GND E1A.GND
ROUT EELOUT
A.VDD EEL.REF
A.VDD EE.R.REF
1OUT
2GND
3IN
123
a
7j U
1Emitter
2Base
3Collector
(FRONT VIEW) (TOP VIEW) (TOP VIEW)
(TOP VIEW)
11

DR-550mk2 APRIL.1992
APPENDIX
Error Meseage x^yiz v
Mc_
II LI
Cause 1:The DR- 550 was unable to completely process
an overly large amount of MIDI message that
was received.
Remedy :Reduce the amount of MIDI message sent by
the transmitting device.
*Press [STOP/CONT] to return to the Song
Play mode.
•J1S1: **©MIDItt$6£gff LfcfctolCDR-550*f*rftia
K-otZo
MS :i£M0MIDI1t$8£$e>LT</?3l'o
*[STOP/CONT] #9 ylkWtb'J 's'? •*- KICMO
£To
Cause 2:MIDI message could not be received correctly due
to an improper connection in the MIDI cabling.
Remedy :Check to make sure connections are in order,
then try the operation again.
•mm2-. MIDI MIDI 1*«*IEL<S
MS :jjStlfiBLT fc7-£&ft£¥>yELT<fc'a
t'o
*Press [STOP/CONT] to return to the Song *[STOP/CONT] y&NTt Vy$* ~}\/4 •=E- K(CR U
Play mode. £lto
H0_
1/ L
1
Cause 1:During the process of verification, the correct
data was not received.
Remedy :Readjust the volume on the tape recorder, and
try performing Verify again. Should you still get
the error message, the data should be saved
again from the beginning.
Cause 2:[STOP/CONT] was pressed during the
verification process.
Remedy :Perform the verification over again.
Cause 1:During loading, correct data was not received.
Remedy :Readjust the volume on the tape recorder and
try again.
Cause 2:[STOP/CONT] was pressed during the loading
process.
Remedy :Carry out the Load procedure once again.
•J5H1:
MS :77
4tT </c£l'o
fe--76'6Y>yii:LT</ifSl'o
•mm2: ^U7 7d’©ii^T' [STOP/CONT] fc 0
MS :t)7llt^U77d'(Dfi^^^yitLT</c'$L'0
•SCSI: -K+(CjEU'7f-^*56tfffin**'ofco
MS :t)?1Jl^ l
J77
VyXLT<fc $l'o
•®S2: -KOitfpT" [STOP/CONT] **>£ffPL/c0
Ic_
LLl
12

1994. 06. 17
ER00118
DR-5 5Omk HSERVICE NOTES
ERRATA &SUPPLEMENT JE§£H &£?][] ifffi
(Small errors are ignored. fi || “C Uxi7 )