Roland WP-20G Operating and maintenance manual

SERVICE NOTES
Issued by RJA
Copyright © 2002 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 (0800) (AS)
17058016E0
Feb.2002 WP-20G(T)
SPECIFICATINS................................................................2
LOCATION OF CONTROLS ..........................................4
LOCATION OF CONTROLS PARTS LIST ...................5
EXPLODED VIEW............................................................6
EXPLODED VIEW............................................................8
EXPLODED VIEW PARTS LIST.....................................9
PARTS LIST......................................................................10
IDENTIFYING VERSION NUMBER ...........................14
TEST MODE.....................................................................14
Block Diagram.................................................................18
Circuit Board (JACK BOARD) ......................................20
Circuit Board (JACK BOARD) ......................................21
Circuit Diagram (JACK BOARD) .................................22
Circuit Board (PANEL BOARD)...................................24
Circuit Diagram (PANEL BOARD)..............................25

2
Feb.2002
SPECIFICATINS
WP-20G: GK Effect
Controls
Master On/Off Pedal
Effects On/Off Pedal
TYPE Knob
COLOR Knob
LEVEL Knob
MODE Knob
EFFECT LEVEL Knob
NORMAL PU MIX Switch
Indicator
POWER Indicator (serves also as battery check indicator)
MASTER ON/OFF Indicator
EFFECTS ON/OFF Indicator
Connectors
GUITAR OUT Jack
GUITAR RETURN Jack
GK IN Connector
OUTPUT Jack
DC IN Jack (DC 9 V)
Nominal Input Level
GUITAR RETURN: -20 dBu
Input Impedance
GUITAR RETURN: 1 M(ohm)
Nominal Output Level
OUTPUT: -20 dBu
GUITAR OUT: -20 dBu
Nominal Output Impedance
OUTPUT: 1 k(ohm)
GUITAR OUT: 100 (ohm)
Recommended Load Impedance
10 k(ohm) or greater
Residual Noise Level
• 96 dBu(GK IN: terminated, Distortion: OFF, NORMAL PU MIX: OFF,
IHF-A,typ)
Power Supply
DC 9 V: Dry Battery x 6, AC Adaptor
Current Draw
150 mA (9 V, with GK-2A)
* Expected battery life under continuous use:
Carbon: 2 hours
Alkaline: 6 hours
These figureswill 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
Dry Battery (LR6 (AA) type) x 6(#********)
Owner’s Manual English (#G6017300)
Japanese (#G6017299)
Roland Service (Information sheet)
Options
AC Adaptor: PSA series
Divided pickup: GK-2A (Roland)
Unit Selector: US-20 (Roland)
GK Connecting Cable: GKC-3 (3 m), GKC-5 (5 m), GKC-10 (10 m), C-13B(10 m)
(Roland)
GK Parallel Box: GKP-4 (Roland)
* 0 dBu = 0.775 Vrms
* In the interest of product improvement, the specifications and/or appearrance of
this unit are subject to change without prior notice.

3
WP-20G(T)

4
Feb.2002
LOCATION OF CONTROLS
fig.panel-h
q w
i u y t
a
b
e
c
!4
!2
!3
b
o !0 !1
r
!7 !5
!8
!6

5
WP-20G(T)
LOCATION OF CONTROLS PARTS LIST
[Parts]
[Screw]
No. Part Code Part Name Q’ty
1 F344940301 ADAPTOR JACK DJ-0711B-020 1
2 G2017146 CASE 1
3 G2017148 BOTTOM COVER 1
3 G2357118 BOTTOM FOOT 2
3 G2017621 BATTERY COVER 1
3 G2537726 LABEL 1
4 13449155MF PHONE JACK (MONO) HTJ-064-12I 2
5 G2217150 REAR PANEL 1
6 00564556 DIN TCS5093-10-4152 1
7 F3159104 SWITCH SS037-P222BHH-PE9 1
8 13449150MF PHONE JACK (STEREO) HTJ-064-12D 1
9 G2477122 R-KNOB 1
F3279804 POTENTIOMETER 6 CLICKS 50KB RD901-40-125F-B54-06D 1
10 G2217146 PANEL 1
11 G2477122 R-KNOB 1
F3279803 POTENTIOMETER 11 CLICKS 50KB RD901-40-125F-B54-11D 1
12 G2477122 R-KNOB 3
F3279802 POTENTIOMETERNO CLICK 50KB RD901-40-125F-B54-00D 3
13 F5029126 POWER LED L-113GDT 1
14 G2357116 PEDAL PLATE 62X53 2
15 G2187530 PEDAL R 1
16 G2217153 LED PANEL 1
17 G2187531 PEDAL L 1
18 1502928100 LED (RED) L-34HDSL 2
No. Part Code Part Name Q’ty
a H5019125 SCREW M3X10 PAN HEAD W/SW+PW FE BC 2
b H5029850 SCREW M4X6 HEXAGON SOCKET BUTTON HEAD FE 4
c H5029851 PEDAL SHAFT 2

6
Feb.2002
EXPLODED VIEW
fig.panel-h
x5
x4
x5
21
c
k
24
26
x3
d
x7
x2
x3
x3
23
f
e
n
b
25
28
27
1

7
WP-20G(T)
1
2
5
3
i
4
g
hRIGHT SIDE
LEFT SIDE
9
6
7
8

8
Feb.2002
EXPLODED VIEW
fig.panel-h
a
11
18
m
12 18
11
16
j
14
15
17
10
13

9
WP-20G(T)
EXPLODED VIEW PARTS LIST
[Parts]
[Screw]
No. Part Code Part Name Q’ty
1 G2017146 CASE 1
2 G2357111 CUSHION R 2
3 H5029851 PEDAL SHAFT 2
4 2215770201 PEDAL GUIDE BUSH 215-702 2
5 2217710900 COIL SPRING 214-109 2
6 G2357116 PEDAL PLATE 62X53 2
7 G2357115 PEDAL FOOT M8 2
8 G2187530 PEDAL R 1
9 G2187531 PEDAL L 1
10 G2017148 BOTTOM COVER 1
11 G2357118 BOTTOM FOOT 2
12 G2017621 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 G2537726 LABEL 1
21 G2477122 R-KNOB 5
23 G2257131 INSULATING SHEET BOTTOM 1
24 G2217146 PANEL 1
25 G2217150 REAR PANEL 1
26 G2217153 LED PANEL 1
27 75D4820000 JACK BOARD ASSY 1
26 75D4830200 PANEL BOARD ASSY 1
No. Part Code Part Name Q’ty
a H5019115 SCREW M3X8 PAN TAPPING-2 FEBZC 2
b H5019110 SCREW M3X6 PAN TAPPING-2 FEZC 7
c H5029850 SCREW M4X6 HEXAGON SOCKET BUTTON HEAD FE 4
d H5039205 WASHER 12.5X9.5X0.5/0.9 INTERNAL TOOTH FENI 3
e H5039112 WASHER M9 3
f H5039510 NUT M9X12X2 FENI 3
g H5029852 SCREW 4M3 FEBZC HEXAGON SOCKET BUTTON HEAD 2
h H5039413 NYLON WASHER M4.1X7.5X0.5 BLACK 2
I H5039414 NYLON WASHER M5.1X9.5X0.5 BLACK 2
j H5019430 SCREW M2.6X5 BINDING HEAD TAPTITE FEZC 2
k H5039521 VR ACCESSORY NUT M7 5
m H5019115 SCREW M3X8 PAN TAPPING-2 FEBZC 5
n H5019125 SCREW M3X10 PAN HEAD W/SW+PW FE BC 2

10
Feb.2002
PARTS LIST
fig.part1e
JB -> JACK BOARD ASSY, PB -> PANEL BOARD ASSY
CASING
G2357116 PEDAL PLATE 62X53 2
G2017620 BATTERY CASE 1
G2017621 BATTERY COVER 1
G2017148 BOTTOM COVER 1
G2357118 BOTTOM FOOT 2
G2017146 CASE 1
# G2217153 LED PANEL 1
# G2217146 PANEL 1
G2187531 PEDAL L 1
G2187530 PEDAL R 1
H5029851 PEDAL SHAFT 2
G2217150 REAR PANEL 1
KNOB,BUTTON
G2477122 R-KNOB 5
SWITCH
13129778 SKQKAH TACT SWITCH SW1, SW2 on Panel Board 2
F3159104 SS037-P222BHH-PE9 SWITCH SW1 on Jack Board 1
JACK,EXT TERMINAL
13449150MP HTJ-064-12D PHONE JACK (STEREO) JK2 on Jack Board 1
13449155MF HTJ-064-12I PHONE JACK (MONO) JK1, JK3 on Jack Board 2
00564556 TCS5093-10-4152 DIN CN1 on Jack Board 1
F344940301 DJ-0711B-020 ADAPTOR JACK JK4 on Jack Board 1
PWB ASSY
# 75D4820000 JACK BOARD ASSY 1
# 75D4830200 PANEL BOARD ASSY 1
IC
02455056 S-80930ALMP-DAT-T2 IC (RESET) IC8 on Jack Board 1
02122423 AN78L07M-E1 IC (REGULATOR) IC11 on Jack Board 1
02124634 AN79L07M-E1 IC (REGULATOR) IC9 on Jack Board 1
00458034 TC75S51F TE85R IC (OP AMP) IC7 on Jack Board 1
01906156 S-8520E33MC-BJS-T2 IC (DC-DC REGULATOR) IC12 on Jack Board 1
02568567 MB3778PFV IC (DC-DC CONVERTER) IC10 on Jack Board 1
15189261 M5218AFP-600E IC (BIPOLAR OP AMP) IC1 on Jack Board 1
02451434 AK4552VT IC (AD/DA) IC2, IC3, IC6 on Jack Board 3
# 02569812 MN101C30A VER.1.00 IC (8BIT CPU) IC4 on Jack Board 1
02568578 MN101C427BL VER.1.00 IC (8BIT CPU) IC5 on Jack Board 1
TRANSISTOR
F5309111 2SA1182Y TRANSISTOR Q15, Q18 on Jack Board 2
15309104 2SA1586-GR(TE85R) TRANSISTOR Q10, Q11 on Jack Board 2
15319108 2SC-3324GR-TE85R TRANSISTOR
Q2, Q4, Q5, Q6, Q8, Q9, Q12, Q21 on Jack Boa
8
F5319104 2SC2859Y TRANSISTOR Q19 on Jack Board 1
15319107 2SC4116-GR(TE85R) TRANSISTOR Q13 on Jack Board 1
15329521 RN1307(TE85R) TRANSISTOR Q7, Q22 on Jack Board 3
F5139608 IRF7606 POWER MOS FET Q16 on Jack Board 1
15329103 2SK880GR-TE85R FET TRANSISTOR Q1, Q3, Q20 on Jack Board 2
DIODE
02562878 02DZ5.1-Y(TPH3) ZENER DIODE D2 on Jack Board 1
01019534 1SS355 TE-17 SWITCHING DIODE D1, D4, D9, D10 on Jack Board 4
F5029126 L-113GDT POWER LED LED3 on Panel Board 1
SAFETY PRECAUTIONS:
The parts marked have
safety-relatedcharacteristics.Use
only listed parts for replacement.
SAFETY PRECAUTIONS:
The parts marked have safety-related characteristics. Use only listed parts for replacement.
QTY PART NUMBER 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.
NOTE: The parts marked # are new. (initial parts)

11
WP-20G(T)
1502928100 L-34HDSL LED (RED) LED1, LED2 on Panel Board 2
F5339137 SS14 VF=0.45V DIODE D5,D6,D7,D8 on Jack Board 4
15339120T0 1SS302(TE85R) ARRAY DIODE DA1, DA2, DA3 on Jack Board 3
RESISTOR
00566867 RPC05T 100 J MTL.FILM RESISTOR R25,R40,R60 on Jack Board 3
00567023 RPC05T 101 J MTL.FILM RESISTOR R91 on Jack Board 1
00567156 RPC05T 102 J MTL.FILM RESISTOR R4 on Jack Board 1
00567289 RPC05T 103 J MTL.FILM RESISTOR
R3,R8,R19,R24,R45,R48,R54,R56,R57,R67,R79,R8
13
00567412 RPC05T 104 J MTL.FILM RESISTOR R7,R11,R96 on Jack Board 3
00567556 RPC05T 105 J MTL.FILM RESISTOR R5,R30,R65,R92,R97,R102 on Jack Board 6
00567290 RPC05T 123 J MTL.FILM RESISTOR R87 on Jack Board 1
00567178 RPC05T 152 J MTL.FILM RESISTOR R90 on Jack Board 1
00567301 RPC05T 153 J MTL.FILM RESISTOR R17,R20,R76 on Jack Board 3
00567434 RPC05T 154 J MTL.FILM RESISTOR R80,R86on Jack Board 2
00567189 RPC05T 182 J MTL.FILM RESISTOR R73 on Jack Board 1
00567312 RPC05T 183 J MTL.FILM RESISTOR R59 on Jack Board 1
00567190 RPC05T 222 J MTL.FILM RESISTOR R70 on Jack Board 1
00567323 RPC05T 223 J MTL.FILM RESISTOR
R6,R10,R13,R15,R22,R26,R33,R41,R51,R62 on Ja
10
00566934 RPC05T 330 J MTL.FILM RESISTOR R93 on Jack Board 1
00567089 RPC05T 331 J MTL.FILM RESISTOR R61,R82,R84 on Jack Board 3
00567234 RPC05T 392 J MTL.FILM RESISTOR R89 on Jack Board 1
00567112 RPC05T 471 J MTL.FILM RESISTOR R68 on Jack Board 1
00567245 RPC05T 472 J MTL.FILM RESISTOR R12,R23,R32,R39,R50,R58,R71,R72,R77,R78,R81 11
00567378 RPC05T 473 J MTL.FILM RESISTOR
R1,R2,R29,R36,R37,R38,R49,R55,R101,R103,R104
11
00567501 RPC05T 474 J MTL.FILM RESISTOR R18,R21,R98,R99 on Jack Board 4
00567134 RPC05T 681 J MTL.FILM RESISTOR R43,R44 on Jack Board 2
00567267 RPC05T 682 J MTL.FILM RESISTOR R74 on Jack Board 1
00567278 RPC05T 822 J MTL.FILM RESISTOR R88 on Jack Board 1
02239612 RR0816P-472-D MTL.FILM RESISTOR R16,R28,R35,R46,R53,R64 on Jack Board 6
01909734 RR0816P-682-D MTL.FILM RESISTOR R14,R27,R34,R42,R52,R63 on Jack Board 6
F5429373 22KF CHIP RESISTOR (1608 TYPE) R66 on Jack Board 1
F5429374 33K OHM F RANK (1%) CHIP RESISTOR (1608 TYPE) R69 on Jack Board 1
POTENTIOMETER
F3279802 RD901-40-125F-B54-00D POTENTIOMETERNO CLICK 50KB VR1, VR3, VR4 on Panel Board 3
F3279804 RD901-40-125F-B54-06D POTENTIOMETER 6 CLICKS 50KB VR5 on Panel Board 1
F3279803 RD901-40-125F-B54-11D POTENTIOMETER 11 CLICKS 50KB VR2 on Panel Board 1
CAPACITOR
02341489 ECPU1C474MA5 MYLAR CAPACITOR(SUBMICRON) C3 on Jack Board 1
F5367542 10/16V ALUMINIUM ELECTROLYTIC CAPACITOR C1, C4 ,C6 on Jack Board 3
F5367546 100/16V ALUMINIUM ELECTROLYTIC CAPACITOR
C35, C39, C79, C82, C84, C85, C86, C88, C94,
13
F5367503 47/6.3V ALUMINIUM ELECTROLYTIC CAPACITOR C21, C70 on Jack Board 2
F5359730 ECJ1VC1H821J CHIP CAPACITOR (1608 TYPE) 1
F5359705 ECUV1H270JCV CHIP CAPACITOR (1608 TYPE) C72 on Jack Board 1
F5359780 GRM39B103K50PT CHIP CAPACITOR (1608 TYPE)
C11, C25, C77, C110, C111, C112, C114, C115,
10
F5359740 GRM39B222K50PT CHIP CAPACITOR (1608 TYPE) C120 on Jack Board 1
F5359775 GRM39B332K50PT CHIP CAPACITOR (1608 TYPE)
C53, C54, C55, C56, C57, C76 on Jack Board
6
F5359750 GRM39B392K50PT CHIP CAPACITOR (1608 TYPE) C64 on Jack Board 1
F5359720 GRM39CH101J50PT CHIP CAPACITOR (1608 TYPE) C2, C9, C12 on Jack Board 3
F5359704 GRM39CH220J50PT CHIP CAPACITOR (1608 TYPE) C58, C60 on Jack Board 2
F5359709 GRM39CH330J50PT CHIP CAPACITOR (1608 TYPE) C75 on Jack Board 1
F5359800 GRM39F104Z25PT CHIP CAPACITOR (1608 TYPE)
C16,C18,C23,C24,C26,C27,C29,C30,C31,C32,C33,
38
F5359790 GRM39F333Z50PT CHIP CAPACITOR (1608 TYPE) C92, C101 on Jack Board 2
F5369601 1/50V CHIP CAPACITOR
C7, C8, C13, C14, C19, C22, C28, C41, C42, C
17
02231323 ECJ2VF1C105Z CERAMIC CAPACITOR
C10,C15,C17,C43,C45,C52,C62,C66,C68,C113,C11
12
F3629272KM 47UF/10V ELECTROLYTIC CAPACITOR C1 on Panel Board 1
INDUCTOR,COIL,FILTER
F2449216 SLF7045T-151MR40 SMD COIL L4, L6, L7 on Jack Board 3
12449384 SBT-0115W EMI FILTER L1 on Jack Board 1
F2449210 SLF7032T-4R7M1R7-2(4.7UH) EMD COIL L3, L5 on Jack Board 2
CRYSTAL,RESONATOR
F5299108 HC-49SM 8MHZ CRYSTAL X1 on Jack Board 1
01455201 MA-406 12.288MHZ CRYSTAL X2 on Jack Board 1
CONNECTOR
F3439160 53015-0210 2P P=2MM CONNECTOR CN5 on Jack Board 1
# F3439177 A2001WV2-12P CONNECTOR CN2 on Jack Board 1
WIRING,CABLE
G3487163 WIRING BATTERY L=80MM 2P 1
DIODE

12
Feb.2002
# G3417188 WIRING 12P L=65MM P=2MM CN1 on PB to CN 2 on JB 1
F3477146 RIBBON CABLE 3P L=40X5X5MM P=2MM CN3 to CN4 on Jack Board 1
SCREWS
H5019110 SCREW M3X6 PAN TAPPING-2 FEZC 7
H5019115 SCREW M3X8 PAN TAPPING-2 FEBZC 7
H5019125 SCREW M3X10 PAN HEAD W/SW+PW FE BC 2
H5039205 WASHER 12.5X9.5X0.5/0.9 INTERNAL TOOTH FENI 3
H5029850 SCREW M4X6 HEXAGON SOCKET BUTTON HEAD F 4
H5029852 SCREW 4M3 FEBZC HEXAGON SOCKET BUTTON HEAD 2
H5039510 NUT M9X12X2 FENI 3
H5039413 NYLON WASHER M4.1X7.5X0.5 BLACK 2
H5039414 NYLON WASHER M5.1X9.5X0.5 BLACK 2
H5019430 SCREW M2.6X5 BINDING HEAD TAPTITE FEZC 2
H5039521 VR ACCESSORY NUT M7 5
H5039112 WASHER M9 3
PACKING
G2607212 PACKING CASE LOWER 1
# G2627216 PACKING CASE UPPER 1
G2237613 SIDE PAD 1
G2237614 REAR PAD 1
MISCELLANEOUS
G2357115 PEDAL FOOT M8 2
2215770201 PEDAL GUIDE BUSH 215-702 1
2217710900 COIL SPRING 214-109 2
G2257130 BATTERY INSULATING
SHEET 1
G2177308 BATTERY TERMINAL(+) 1
G2177307 BATTERY TERMINAL(+-) 1
G2177309 BATTERY TERMINAL(-) 1
G2357111 CUSHION R 2
G2257131 INSULATING SHEET BOTTOM 1
# G2537726 LABEL 1
02123845 LEAF A on Jack Board 1
G2197126 LED GUIDE 1
ACCESSORIES (Standard)
# G6017299 OWNER’S MANUAL JAPANESE 1
# G6017300 OWNER’S MANUAL ENGLISH 1
# ******** DRY BATTERY LR(AA) TYPE 2P 3
40232389 WARRNTY CARD (JAPAN ONLY) 1
WIRING,CABLE

13
WP-20G(T)

14
Feb.2002
IDENTIFYING VERSION
NUMBER
1. Insert the AC adapter plug into the adapter jack while pressing the left
([MASTER ON/OFF] switch), and the right ([EFFECTS ON/OFF] switch)
pedals.
2. Release the left and right pedals when the “POWER” LED comes on.
3. Press the left then the right pedal within 4 seconds.
4. Pressing the right pedal displays the version number as shown below.
TEST MODE
Required items
• Guitar with GK-2A + GK cable
• Oscilloscope
• Noise Meter
• Monitor speaker
• ADAPTOR (PSA TYPE)
• Bypass Cable
Entering Test Mode
1. Connect the GK-2A to GK IN using the GK cable.
Set the selection switch of the GK-2A to ‘SYNTH’.
2. Insert the AC adapter plug into the adapter jack while pressing the left
([MASTER ON/OFF] switch)
and the right ([EFFECTS ON/OFF] switch) pedals.
3. Release the left and right pedals when the “POWER” LED comes on.
4. Press the left then the right pedal within 4 seconds.
5. The unit will enter the test mode (selection waiting status), and all LEDs
will come on.
Note: When the unit enters the test mode, it simultaneously performs an
automatic DSP check.
The state of the LEDs when entering the test mode differs depending on
this result.
For further information, refer to “1. DSP check”.
Note: After performing 2, perform 3 and 4 within 4 seconds.
After the time has lapsed or if a different switch is operated, the unit does
not enter the test mode but starts normal operation.
Exiting Test Mode
Pressing the left pedal ([MASTER ON/OFF] switch) while in test item selection
status exits the test mode.
Skipping to a specific test item
Each test item and operator for running them are as follows:
Items 2 to 4 can be selected from the selection waiting status.
When the first item is completed, it automatically returns to the selection
waiting status.
Note : “5. Normal pick-up (OUT/RETURN JACK) check “ and “6. Switch and
shock noise check “ ,and “7. Battery operation check” are not test items within
the Test mode program.
Perform these tests in normal operating mode without entering Test mode.
1. DSP check: enter the test mode.
2. Switch check: press the [NORMAL PU MIX] switch.
3. Volume check: controls the TYPE volume.
4. CODEC check: controls the MODE volume.
5. Normal pick-up (OUT/RETURN JACK) check: re-enters power (normal
operation state)
6. Switch and shock noise check(normal operation state)
7. Battery operation check(normal operation state)
Caution: After repairing or servicing the WP-20G, you must be sure to check
all items.
Details of test items
1.DSP check
1. Enters the test mode.
2. When it enters the test mode, it automatically checks the internal memory
(IRAM & PRAM) of the DSP.
3. If no problem exists, the “MASTER ON/OFF” LED and the “EFFECTS
ON/OFF LED” come on and the unit stands by for test item selection.
4. The state of the LEDs and the reason when a problem occurs are as
follows:
Please check the IC5
Note: The next test cannot be performed if a problem occurs.
2.Switch check
1. Moving the [NORMAL PU MIX] switch to either side enters the switch
check.
(The unit enters the switch check when the [NORMAL PU MIX] switch is
moved from ‘ON’ to ‘OFF’ or vice versa).
2. Press the switch in the following order.
Confirm that the LED displays as follows:
Note: When several switches are simultaneously pressed, the “MASTER ON/
OFF “ LED and the “EFFECTS ON/OFF LED” simultaneously flash, and you
cannot proceed to the next test.
Note: When the left pedal check is completed, the “MASTER ON/OFF” LED
and the “EFFECTS ON/OFF LED” come on and the unit stands by for test item
selection.
MASTER ON/OFF
LED EFFECTS ON/OFF LED
1.00 blinking dark
MASTER ON/OFF
LED EFFECTS ON/OFF LED
IRAM error dark blinking
PRAM error blinking dark
MASTER ON/OFF
LED EFFECTS ON/OFF LED
NORMAL PU MIX blinking illuminated
GK-2A S1 illuminated blinking
GK-2A S2 blinking dark
LEFT PEDAL dark blinking
RIGHT PEDAL illuminated illuminated

15
WP-20G(T)
3.Volume check
1. To enter the volume check, set the GK-2A’s selection switch to ‘SYNTH’,
turn all volume controls including the GK-2A’s volume (SYNTHVOL) to
minimum and control the TYPE volume.
2. Perform the check in the following order: Confirm that the LED comes on
and off as follows:
• TYPE volume check
Turn the TYPE volume control one click at a time from the left (minimum) and
confirm that the LED changes as follows:
-> ->
-> ->
->
• COLOR volume check
Turn the COLOR volume control from the left (minimum) and confirm that the
LED changes as follows:
-> ->
->
• LEVEL volume check
Turn the LEVEL volume control from the left (minimum) and confirm that the
LED changes as with the COLOR volume.
• MODE volume check
Turn the MODE volume control one click at a time from the left (minimum)
and confirm that the LED
changes as follows:
-> ->
-> ->

16
Feb.2002
-> ->
-> ->
-> ->
• EFFECT LEVEL volume check
Turn the EFFECT LEVEL volume from the far left (minimum) to far right
(maximum),and verify that the LEDs change as with the color volume.
• GK-2A SYSTH VOL volume check
Turn the GK-2A SYSTH VOL volume from the far left (minimum) to the far
right (maximum), and verify that the LEDs change as with the COLOR
volume.
• Press the right pedal and complete the check.
The “MASTER ON/OFF” LED and the “EFFECTS ON/OFF LED” come on
and the unit stands by for test item selection.
4.CODEC check
Moving the MODE volume control from ‘DELAY 1’ initiates the CODEC
check.
Note: When the MODE volume control is set to ‘DELAY+CHORUS 1-5’ or
‘CHORUS’, the “MASTER ON/OFF LED” and the “EFFECTS ON/OFF LED”
come on and the unit stands by for test item selection.
• ERAM check
1. Setting the MODE volume control to ‘DELAY2’ automatically initiates the
check.
The “MASTER ON/OFF” LED and the “EFFECTS ON/OFF “ LED
flash alternately.
2. Confirm that the “MASTER ON/OFF” LED and the “EFFECTS ON/OFF
“ LED are both on.
3. If a problem exists, the “MASTER ON/OFF” LED and the “EFFECTS
ON/OFF” LED simultaneously flash and you cannot proceed to the next
check.
Please check the IC5
• D/A check & MUTE check
1. Setting the MODE volume control to ‘DERAY 3’ turns the “MASTER
ON/OFF” LED on, and turns the “EFFECTS ON/OFF” LED off, and
enters the D/A check.
2. Connect an oscilloscope to the OUTPUT jack, and confirm that a 0.25Vp-p
rectangular wave of 375 Hz is output.
3. Confirm that the “MASTER ON/OFF “ LED flashes and the waveform is
muted (no waves are output) when the left pedal is pressed.
4. Press the left pedal again, and confirm that the waveform is output again.
• A/D thru check
1. Setting the MODE volume control to ‘DERAY 4’ initiates the A/D thru
check.
Set the switch of the GK-2A to ‘SYNTH’.
2. It will automatically enter the string 1 check.
Confirm that the “MASTER ON/OFF” LED comes on and the “EFFECTS
ON/OFF” LED goes off.
Connect an oscilloscope to the OUTPUT jack, and confirm that only the
waveform for string 1 is output.
Confirm that no waveforms are output when unselected strings are
played.
3. Pressing the [UP/S2] switch of the GK-2A initiates the string 2 check.
Confirm that both the “MASTER ON/OFF” LED and “EFFECTS ON/
OFF” LED go off, and that only the waveform for string 2 is output.
Also, confirm that no waveforms are output when unselected strings are
played.
4. Press the [UP/2S] switch of the GK-2A as above, and confirm that only
the selected waveforms of strings 3,4,6 and 5 are output.
The selected string and the LED display are as follows.
Note: To return to the previous string check, press the [DOWN/S1] switch of
the GK-2A
MASTER ON/OFF
LED EFFECTS ON/OFF LED
1st string illuminated dark
2nd string dark dark
3rd string illuminated dark
4th string dark illuminated
6th string illuminated illuminated
5th string dark illuminated

17
WP-20G(T)
• Noise check
1. Setting the MODE volume control to ‘DELAY 5’ turns the “MASTER
ON/OFF” LED off and the “EFFECTS ON/OFF LED” to flash, then
enters the noise check.
2. Disconnect the GK-2A, and connect a noise meter to OUTPUT JACK
without connecting anything to GK IN.
3. Confirm that the noise level is -90 dBm (DIN-Audio) or lower.
Note: Noise check disconnects the GK-2A from the plug, for the time being.
5.Normal pick-up (OUT/RETURN JACK)
check
1. Turn the [NORMAL PU MIX] switch on while the main power supply is
off, then insert the AC adapter plug into the adapter jack.
2. Confirm that the “MASTER ON/OFF” LED is on.
3. Set the switch of the GK-2A to ‘GUITAR’.
4. Connect an oscilloscope to the OUTPUT jack, and confirm that a
waveform is output when the guitar is played.
5. Connect one side of the bypass cable to GUITAR OUT jack, and confirm
that no waveform is output when the guitar is played.
6. Connect the remaining side of the bypass cable to RETURN jack, and
confirm that a waveform is output when the guitar is played.
7. Confirm that no waveform is output when the guitar is played while the
[NORMAL PU MIX] switch is off.
6.Switch and shock noise check
1. Turn the [NORMAL PU MIX] switch off, and set up the knobs of panel as
follows.
TYPE :SAW LEAD
COLOR :CENTER
LEVEL :CENTER
DELAY :DELAY-5
EFFCT LECEL:CENTER
and set the GK-2A’s SYNTH VOL to maximum and the selection switch
to ‘MIX’.
Place the guitar in as noiseless an environment as possible.
2. Connect the monitor speaker to OUTPUT jack.
3. Press the left pedal repeatedly, and switch the ‘MASTER ON’ and
‘MASTER OFF’.
4. Confirm that no abnormal switch noise is generated.
5. Press the left pedal and turn the “MASTER ON/OFF” LED off
(‘MASTEROFF’), and subject the unit to a shock from 10 cm high to
confirm that no abnormal noise is generated.
6. Press the left pedal and turn the “MASTER ON/OFF “ LED on
(‘MASTERON’), and subject the unit a shock from 10cm high to confirm
that no abnormal noise is generated.
7.Battery operation check
1. Put the batteries in the battery compartment and insert the plug into the
OUTPUT jack.
2. Check that power is turned on.
3. Check that the unit is operating normally.
Note : Always check the battery after repairing or servicing the product.

19
Feb.2002 WP-20G(T)
Block Diagram
fig.block
GUITAR RETURN
GUITAR OUT
OUTPUT
MIX ON/OFF
BUFFER
CODEC
CODEC
CODEC
IC2
IC3
IC6
DSP
IC5
CPU
IC4
IC1
FET SW
FET SW
SUMMING
BUFFER
IC1
CN2
BUFFER
GK IN
BUFFER
IC7
SYNTH VOL
S1
S2
RESET
IC8
CN1
IC10 DC-DC CONVERTER
IC11 REGULATOR
IC9 REGULATOR
IC12 DC-DC CONVERTER +3.3V
+7V
-7V
CN3 CN4
BATTERY CN5
LED1, 2, 3
SW1, 2
VR1, 2, 3, 4, 5
PANEL BOARD ASSY
JACK BOARD ASSY
DC IN
WIRING 12P
RIBBON 2P
Q1
Q3
Q20
CN1
JK1
JK2
JK4
SW1
JK3

20
Feb.2002
Circuit Board (JACK BOARD)
fig.panel-h
View from component side

21
WP-20G(T)
Circuit Board (JACK BOARD)
fig.panel-h
View from foil side