Roland BOSS RT-20 Operating and maintenance manual

SERVICE NOTES
Issued by RJA
Copyright © 2006 ROLAND CORPORATION
All rights reserved. No part of this publication may be reproduced in any form without the written permission
of ROLAND CORPORATION.
Printed in Japan (0500) (SC-KWS)17058357E0
Dec. 2005 RT-20
Table of Contents
Cautionary Notes ..............................................................2
Specifications .....................................................................3
Location of Controls .........................................................4
Location of Controls Parts List........................................5
Exploded View (1).............................................................6
Exploded View (1) Parts List...........................................6
Exploded View (2).............................................................7
Exploded View (2) Parts List...........................................7
Exploded View (3).............................................................8
Exploded View (3) Parts List...........................................8
Exploded View (4).............................................................9
Exploded View (4) Parts List...........................................9
Parts List ...........................................................................10
Checking the Version Number......................................13
About Updating...............................................................13
Test Mode .........................................................................13
Block Diagram .................................................................20
Circuit Board (JACK BOARD).......................................22
Circuit Board (PANEL BOARD) ...................................23
Circuit Diagram (JACK BOARD)..................................24
Circuit Diagram (PANEL BOARD) ..............................26

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Dec. 2005 RT-20
Cautionary Notes
Before beginning the procedure, please read through this document.
No User Data
This product cannot save user data. Backing up user data during servicing is
not required.
Parts List
A component whose part code is ******** cannot be supplied as a service part
because one of the following reasons applies.
• Because it is supplied as an assembled part (under a different part code).
• Because a number of circuit boards are grouped together and supplied as
a single circuit board (under a different part code).
• Because supply is prohibited due to copyright restrictions.
• Because reissuance is restricted.
• Because the part is made to order (at current market price).
Part Replacement
When replacing components near the power-supply circuit or a heat-
generating circuit (such as a circuit provided with a heat sink or including a
cement resistor), carry out the procedure according to the instructions with
respect to the part number, direction, and attachment position (mounting so as
to leave an air gap between the component and the circuit board, etc.).
Circuit Diagram
In the circuit diagram, ‘NIU’ is an abbreviation for ‘NOT IN USE’.
The circuit board and circuit-board diagram show silkscreened indications, but
no components are mounted.

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Dec. 2005 RT-20
Specifications
RT-20: Rotary Sound Processor
Nominal Input Level
-20 dBu
Input Impedance
1 MΩ
Output Impedance
1 kΩ
Recommended Load Impedance
10 kΩor greater
Display
VIRTUAL ROTOR
Controls
EFFECT ON/OFF pedal
SLOW/FAST pedal
OVERDRIVE knob
BALANCE knob
RISE TIME knob
MODE knob
FAST SPEED knob
SLOW SPEED knob
DIRECT LEVEL knob
EFFECT LEVEL knob
DRIVE TYPE switch
Indicators
POWER indicator (serves also as battery check indicator)
EFFECT ON/OFF indicator
SLOW/FAST indicator
Connectors
INPUT A (MONO) jack (1/4 inch phone type)
INPUT B jack (1/4 inch phone type)
SPEED (EXP PEDAL) jack (stereo 1/4 inch phone type)
PHONES jack (stereo 1/4 inch phone type)
OUTPUT A (MONO) jack (1/4 inch phone type)
OUTPUT B jack (1/4 inch phone type)
AC Adaptor jack
Power Supply
DC 9 V: Dry battery (R6/LR6 (AA) type) x 6, AC Adaptor
Current Draw
85 mA (9 V max.)
* Expected battery life under continuous use:
Carbon: 6 hours
Alkaline: 10 hours
These figures will vary depending on the actual conditions of use.
Dimensions
173 (W) x 158 (D) x 57 (H) mm
6-13/16 (W) x 6-1/4 (D) x 2-1/4 (H) inches
Weight
1.1 kg / 2 lbs 7 oz (including batteries)
Accessories
Owner’s Manual (#G6017153R0)
Leaflet (“USING THE UNIT SAFELY,” “IMPORTANT NOTES,” and
“Information”) (#G6017303)
Dry battery (R6 (AA) type) x 6
* We recommend that alkaline batteries be used when replacing the batteries.
Options
AC Adaptor (PSA-series)
Expression Pedal (Roland EV-5)
* 0 dBu = 0.775 Vrms
* In the interest of product improvement, the specifications and/or appearance of
this unit are subject to change without prior notice.

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Dec. 2005 RT-20
Location of Controls
fig.panel
1
2
4
3
7
11
65 b a4
8 9
10

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Dec. 2005 RT-20
Location of Controls Parts List
[PART]
[SCREW]
No. PART CODE PART NAME DESCRIPTION Q’TY
1 G2357116R0 PEDAL PLATE 62X53 2
2 G2217749R0 LED PANEL 1
3 G2217192R0 PANEL 1
4 75D522N0R0 MINIMUM VR KNOB 8
5 G2567163R0 LED COVER 1
6 G2147880R0 LED LENS 1
7 G2217191R0 REAR PANEL 1
8 F3449415 ADAPTOR JACK KM02009AB 1
9 F3159104 SWITCH SS037-P222BHH-PE9 1
10 13449150 6.5MM JACK HLJ0544-0100109 4
11 F3449707 PHONE JK (STREO) HTJ-064-12DS 2
No. PART CODE PART NAME DESCRIPTION Q’TY
a H5029855 SCREW M4X8 HEXAGON BUTTON HEAD NI 4
b H5029901R0 SCREW M3X10 HEXAGON SOCKET (FE/NI) 4

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Dec. 2005 RT-20
Exploded View (1)
fig.bunkai1
Exploded View (1) Parts List
[PART]
[SCREW]
1
2
5
3
i
4
g
hRIGHT SIDE
LEFT SIDE
9
6
7
8
No. PART CODE PART NAME DESCRIPTION Q’TY
1 75E202T000 CASE 1
2 G2357111R0 CUSHION R 2
3 H5029851 PEDAL SHAFT 2
4 22157702R0 PEDAL GUIDE BUSH 2
5 22177109R0 COIL SPRING 2
6 G2357116R0 PEDAL PLATE 62X53 2
7 G2357115 PEDAL FOOT M8 2
8 G2187529R0 PEDAL R 1
9 75E202T1R0 PEDAL L 1
No. PART CODE PART NAME DESCRIPTION Q’TY
g H5029852 SCREW 4M3 FEBZC HEXAGON SOCKET BU 2
h H5039413 NYLON WASHER M4.1X7.5X0.5 BLACK 2
l H5039414 NYLON WASHER M5.1X9.5X0.5 BLACK 2

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Dec. 2005 RT-20
Exploded View (2)
fig.bunkai2
Exploded View (2) Parts List
[PART]
[SCREW]
26
c
k
21
20
d
27
24
No. PART CODE PART NAME DESCRIPTION Q’TY
20 G2147880R0 LED LENS 1
21 75D522N0R0 MINIMUM VR KNOB 8
24 G2217192R0 PANEL 1
26 G2217749R0 LED PANEL 1
27 G2567163R0 LED COVER 1
No. PART CODE PART NAME DESCRIPTION Q’TY
c H5029855 SCREW M4X8 HEXAGON BUTTON HEAD NI 4
d H5029901R0 SCREW M3X10 HEXAGON SOCKET (FE/NI) 4
k H5039521R0 NUT M7 8

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Dec. 2005 RT-20
Exploded View (3)
fig.bunkai3-e
Exploded View (3) Parts List
[PART]
[SCREW]
a
a
12
18
11
16
j
14
15
10
13
17
Refer to Exploded View (4).
Enlargement
Enlargement
No. PART CODE PART NAME DESCRIPTION Q’TY
10 75D422E000 BOTTOM COVER 1
11 G2357118 BOTTOM FOOT 2
12 G2017621R0 BATTERY COVER 1
13 G2017620 BATTERY CASE 1
14 G2177308 BATTERY TERMINAL (+) 1
15 G2177309 BATTERY TERMINAL (-) 1
16 G2177307 BATTERY TERMINAL (+-) 1
17 G2257130 BATTERY INSULATING SHEET 1
18 G2537007R0 BOTTOM COVER LABEL 1
No. PART CODE PART NAME DESCRIPTION Q’TY
a H5019115 SCREW M3X8 PAN TAPPING-2 FEBZC 7
j H5019430 SCREW M2.6X5 BINDING HEAD 2

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Dec. 2005 RT-20
Exploded View (4)
fig.bunkai4
Exploded View (4) Parts List
[PART]
[SCREW]
f
e
25
b
23
28
31
b
29
30
No. PART CODE PART NAME DESCRIPTION Q’TY
23 G225712901 INSULATING SHEET 1
25 G2217191R0 REAR PANEL 1
28 G2197127 JACK SPACER 1
29 75E203J0R0 JACK BOARD ASSY 1
30 75E203P0R0 PANEL BOAD ASSY 1
31 G2147807 JACK HOLDER 1
No. PART CODE PART NAME DESCRIPTION Q’TY
b H5019110 SCREW M3X6 PAN TAPTITE FEZC 13
e H5039158R0 WASHER M9X14X0.5T NI 6
f H5039510R0 NUT M9X12X2T NI 6

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Dec. 2005 RT-20
Parts List
fig.part1e
SAFETY PRECAUTIONS:
The parts marked have
safety-related characteristics. Use
only listed parts for replacement.
NOTE: The parts marked # are new. (initial parts)
Due to one or more of the following reasons,
parts with parts code ******** cannot be supplied as service parts.
• Part supplied only as a component in a complete assembly
• Copyright does not permit the part to be supplied
• Part is sold commercially
The description "Q'TY" means a necessary number of the parts per one product.
CASING
G2357115 PEDAL FOOT M8 2
G2357116R0 PEDAL PLATE 62X53 2
G2017620 BATTERY CASE 1
G2017621R0 BATTERY COVER 1
75D422E000 BOTTOM COVER 1
G2357118 BOTTOM FOOT 2
# 75E202T000 CASE 1
# G2217192R0 PANEL 1
# G2187529R0 PEDAL R 1
# 75E202T1R0 PEDAL L 1
# G2217191R0 REAR PANEL 1
KNOB, BUTTON
75D522N0R0 MINIMUM VR KNOB 8
SWITCH
13129778 TACT SWITCH SKQKAH SW2, SW3 2
JACK, EXT TERMINAL
F3159104 SWITCH SS037-P222BHH-PE9 SW1 1
F3449415 ADAPTOR JACK KM02009AB JK8 1
F3449707 PHONE JK (STREO) HTJ-064-12DS JK1, JK4 2
13449150 6.5MM JACK HLJ0544-0100109 JK2, JK3, JK5, JK6 4
PWB ASSY
# 75E203J0R0 JACK BOARD ASSY 1
# 75E203P0R0 PANEL BOAD ASSY 1
IC
# 04012978 IC (CPU) UPD780034AGK IC11 1
02565501 IC (DSP) TC220CCA0AF-B01 (MR3) IC10 1
F5179125 IC (DC-DC) S-8520E33MC-BJS-T2 IC12 1
F5209150 IC (RESET) S-80130ALMC-JAP-T2 IC16 1
F5289102 IC (OP.AMP) NJM2100M 8P SOP IC3 1
15189261 IC (BIPOLAR OP AMP) M5218AFP-600E IC1, IC2, IC5 3
15289109 IC (BIPOLAR OP AMP) M5216FP-600D IC4 1
F5279309 IC (LED DRIVER) BU2090F-E2 IC13, IC14, IC15 3
02451434 IC (AD/DA) AK4552VT IC6 1
# F5249136R0 IC (CMOS) 74HC4052PW (TSSOP16) IC9 1
TRANSISTOR
F5139608 POWER MOS FET IRF7606 Q14 1
15329103 FET 2SK880GR-TE85R Q1,Q4 2
F5329530 FET 2SK879Y Q2, Q3, Q5, Q7, Q15 5
15319107 TRANSISTOR 2SC4116-GR (TE85R) Q9, Q10, Q11, Q12, Q13 5
DIODE
F5339137 DIODE SS14 VF=0.45V D7, D6 2
F5029126 POWER LED L-113GDT LED1 1
15029281 LED (RED) GL-3PR8 LED34, LED35 2
15339120 DIODE 1SS302 DA1, DA2, DA3, DA4, DA5, DA6, DA7 7
15339119 DIODE 1SS-352 D1, D2, D3, D4, D9 5
# F5029163R0 CHIP LED 19-21UBC/C470/TR8
(CHIP_BLUE)
LED2, LED3, LED4, LED5, LED6, LED7,
LED8, LED9, LED1
16
# F5029162R0 CHIP LED 19-21SURC/S530-A2/TR8 LED18, LED19, LED20, LED21, LED22,
LED23, LED24, LE
16
F5019309 ZENNER DIODE 02DZ5.1-Y D8 1