Sony MDS-S50 (serv.man2) Service Manual ▷ View online
61
MDS-S50
259
258
257
255
254
256
260
259
262
252
253
253
252
251
263
252
253
262
HR901
S102
M101
M103
M102
#1
#1
265
266
253
261
264
267
268
7-4. MECHANISM DECK SECTION-2
(MDM-7A)
Ref. No.
Part No.
Description
Remark
Ref. No.
Part No.
Description
Remark
251
A-4725-471-A BD BOARD, COMPLETE
252
4-908-618-21 SCREW (BTP) (2X6)
253
3-372-761-01 SCREW (M1.7), TAPPING
254
4-226-993-01 RACK
255
4-227-014-01 SPRING (RACK), COMPRESSION
256
4-226-992-01 BASE, SL
257
1-678-514-11 FLEXIBLE, BOARD
0 258
A-4672-541-A OPTICS ASSY (KMS-260B)
259
4-988-560-01 SCREW (+P 1.7X6)
260
4-996-265-01 SHAFT, MAIN
261
4-226-989-01 CHASSIS
262
4-232-270-01 SCREW (1.7X3.5), +PWH
263
4-226-990-01 BASE (BU-A)
264
4-227-023-01 SPRING (SPINDLE), TORSION
265
4-227-004-01 GEAR (LC)
266
4-227-005-01 GEAR (LD)
267
4-227-008-01 GEAR (SC)
268
4-227-009-01 GEAR (SD)
HR901
1-500-670-11 HEAD, OVER WRITE
M101
A-4672-898-A MOTOR ASSY, SPINDLE
M102
A-4735-076-A MOTOR ASSY, SLED
M103
A-4735-074-A MOTOR ASSY, LOADING
S102
1-771-957-11 SWITCH, PUSH (2 KEY)
(REFLECT RATE DETECT, PROTECT DETECT)
The components identified by
mark 0 or dotted line with
mark 0 are critical for safety.
Replace only with part num-
ber specified.
mark 0 or dotted line with
mark 0 are critical for safety.
Replace only with part num-
ber specified.
Les composants identifiés par une
marque 0 sont critiques pour la
sécurité.
Ne les remplacer que par une pièce
portant le numéro spécifié.
marque 0 sont critiques pour la
sécurité.
Ne les remplacer que par une pièce
portant le numéro spécifié.
62
MDS-S50
BD
SECTION 8
ELECTRICAL PARTS LIST
Ref. No.
Part No.
Description
Remark
Ref. No.
Part No.
Description
Remark
NOTE:
• Due to standardization, replacements in the
parts list may be different from the parts speci-
fied in the diagrams or the components used
on the set.
fied in the diagrams or the components used
on the set.
• -XX and -X mean standardized parts, so they
may have some difference from the original
one.
one.
• RESISTORS
All resistors are in ohms.
METAL: Metal-film resistor.
METAL OXIDE: Metal oxide-film resistor.
F: nonflammable
METAL: Metal-film resistor.
METAL OXIDE: Metal oxide-film resistor.
F: nonflammable
• Items marked “*” are not stocked since they
are seldom required for routine service.
Some delay should be anticipated when order-
ing these items.
Some delay should be anticipated when order-
ing these items.
• SEMICONDUCTORS
In each case, u:
µ
, for example:
uA. .
:
µ
A. .
uPA. . :
µ
PA. .
uPB. . :
µ
PB. .
uPC. . :
µ
PC. .
uPD. . :
µ
PD. .
• CAPACITORS
uF:
µ
F
• COILS
uH:
µ
H
Les composants identifiés par une
marque 0 sont critiquens pour la
sécurité.
Ne les remplacer que par une pièce
portant le numéro spécifié.
marque 0 sont critiquens pour la
sécurité.
Ne les remplacer que par une pièce
portant le numéro spécifié.
The components identified by
mark 0 or dotted line with mark
mark 0 or dotted line with mark
0 are critical for safety.
Replace only with part number
specified.
Replace only with part number
specified.
When indicating parts by reference
number, please include the board.
number, please include the board.
A-4725-471-A BD BOARD, COMPLETE
*******************
< CAPACITOR >
C101
1-135-259-11 TANTALUM CHIP 10uF
20%
6.3V
C102
1-135-259-11 TANTALUM CHIP 10uF
20%
6.3V
C103
1-162-970-11 CERAMIC CHIP
0.01uF
10%
25V
C104
1-164-227-11 CERAMIC CHIP
0.022uF
10%
25V
C105
1-115-416-11 CERAMIC CHIP
0.001uF
5%
25V
C106
1-162-970-11 CERAMIC CHIP
0.01uF
10%
25V
C107
1-162-970-11 CERAMIC CHIP
0.01uF
10%
25V
C108
1-162-969-11 CERAMIC CHIP
0.0068uF 10%
25V
C109
1-164-677-11 CERAMIC CHIP
0.033uF
10%
16V
C110
1-163-038-11 CERAMIC CHIP
0.1uF
25V
C111
1-117-720-11 CERAMIC CHIP
4.7uF
10V
C112
1-110-563-11 CERAMIC CHIP
0.068uF
10%
16V
C113
1-162-968-11 CERAMIC CHIP
0.0047uF 10%
50V
C114
1-125-837-11 CERAMIC CHIP
1uF
10%
6.3V
C115
1-162-966-11 CERAMIC CHIP
0.0022uF 10%
50V
C116
1-164-227-11 CERAMIC CHIP
0.022uF
10%
25V
C117
1-162-970-11 CERAMIC CHIP
0.01uF
10%
25V
C118
1-165-176-11 CERAMIC CHIP
0.047uF
10%
16V
C119
1-165-176-11 CERAMIC CHIP
0.047uF
10%
16V
C120
1-164-156-11 CERAMIC CHIP
0.1uF
25V
C121
1-164-156-11 CERAMIC CHIP
0.1uF
25V
C125
1-117-720-11 CERAMIC CHIP
4.7uF
10V
C128
1-164-156-11 CERAMIC CHIP
0.1uF
25V
C131
1-117-720-11 CERAMIC CHIP
4.7uF
10V
C132
1-164-156-11 CERAMIC CHIP
0.1uF
25V
C133
1-164-156-11 CERAMIC CHIP
0.1uF
25V
C141
1-126-206-11 ELECT CHIP
100uF
20%
6.3V
C142
1-164-156-11 CERAMIC CHIP
0.1uF
25V
C143
1-164-156-11 CERAMIC CHIP
0.1uF
25V
C144
1-162-970-11 CERAMIC CHIP
0.01uF
10%
25V
C145
1-164-156-11 CERAMIC CHIP
0.1uF
25V
C146
1-117-720-11 CERAMIC CHIP
4.7uF
10V
C147
1-117-720-11 CERAMIC CHIP
4.7uF
10V
C151
1-117-370-11 CERAMIC CHIP
10uF
10V
C152
1-164-156-11 CERAMIC CHIP
0.1uF
25V
C153
1-164-156-11 CERAMIC CHIP
0.1uF
25V
C154
1-126-206-11 ELECT CHIP
100uF
20%
6.3V
C155
1-164-156-11 CERAMIC CHIP
0.1uF
25V
C156
1-164-156-11 CERAMIC CHIP
0.1uF
25V
C157
1-164-156-11 CERAMIC CHIP
0.1uF
25V
C158
1-162-927-11 CERAMIC CHIP
100PF
5%
50V
C159
1-162-927-11 CERAMIC CHIP
100PF
5%
50V
C160
1-162-927-11 CERAMIC CHIP
100PF
5%
50V
C161
1-162-970-11 CERAMIC CHIP
0.01uF
10%
25V
C162
1-162-970-11 CERAMIC CHIP
0.01uF
10%
25V
C163
1-125-891-11 CERAMIC CHIP
0.47uF
10%
10V
C164
1-162-927-11 CERAMIC CHIP
100PF
5%
50V
C165
1-162-968-11 CERAMIC CHIP
0.0047uF 10%
50V
C166
1-125-891-11 CERAMIC CHIP
0.47uF
10%
10V
C167
1-164-245-11 CERAMIC CHIP
0.015uF
10%
25V
C169
1-164-156-11 CERAMIC CHIP
0.1uF
25V
C171
1-164-156-11 CERAMIC CHIP
0.1uF
25V
C172
1-164-156-11 CERAMIC CHIP
0.1uF
25V
C180
1-117-370-11 CERAMIC CHIP
10uF
10V
C181
1-126-206-11 ELECT CHIP
100uF
20%
6.3V
C182
1-163-038-11 CERAMIC CHIP
0.1uF
25V
C183
1-164-156-11 CERAMIC CHIP
0.1uF
25V
C184
1-117-970-11 ELECT CHIP
22uF
20%
10V
C185
1-131-872-91 CERAMIC CHIP
1000PF
10%
630V
C191
1-126-206-11 ELECT CHIP
100uF
20%
6.3V
C192
1-164-156-11 CERAMIC CHIP
0.1uF
25V
C193
1-126-206-11 ELECT CHIP
100uF
20%
6.3V
C194
1-164-156-11 CERAMIC CHIP
0.1uF
25V
C195
1-164-156-11 CERAMIC CHIP
0.1uF
25V
C196
1-164-156-11 CERAMIC CHIP
0.1uF
25V
C1401
1-117-720-11 CERAMIC CHIP
4.7uF
10V
< CONNECTOR >
CN101
1-766-833-21 CONNECTOR, FFC/FPC (ZIF) 21P
CN102
1-784-835-21 CONNECTOR, FFC (LIF (NON-ZIF)) 27P
CN103
1-784-834-21 CONNECTOR, FFC (LIF (NON-ZIF)) 23P
* CN104
1-580-055-21 PIN, CONNECTOR (SMD) 2P
CN105
1-784-859-21 CONNECTOR, FFC (LIF (NON-ZIF)) 7P
< DIODE >
D101
8-719-988-61 DIODE 1SS355TE-17
D181
8-719-080-81 DIODE FS1J6
D183
8-719-080-81 DIODE FS1J6
< IC >
IC101
8-752-080-95 IC CXA2523AR
IC102
8-759-473-51 IC TLV2361CDBV
IC141
8-759-430-25 IC BH6511FS
• Abbreviation
AR
: Argentina model
AUS : Australian model
BR
BR
: Brazilian model
CND : Canadian model
HK : Hong Kong model
SP
HK : Hong Kong model
SP
: Singapore model
Ref. No.
Part No.
Description
Remark
Ref. No.
Part No.
Description
Remark
63
MDS-S50
BD
IC151
8-752-404-64 IC CXD2662R
IC153
8-759-671-27 IC MSM51V4400E-70TS-K
IC171
8-759-096-87 IC TC7WU04FU (TE12R)
IC181
8-759-481-17 IC MC74ACT08DTR2
IC190
8-759-460-72 IC BA033FP-E2
IC195
8-759-640-41 IC BR24C08F-E2
< SHORT >
JW201
1-216-295-11 SHORT
0
JW202
1-216-295-11 SHORT
0
JW203
1-216-295-11 SHORT
0
JW903
1-216-295-11 SHORT
0
JW904
1-216-295-11 SHORT
0
< COIL/SHORT >
L101
1-500-245-11 FERRITE
0uH
L102
1-500-245-11 FERRITE
0uH
L103
1-500-245-11 FERRITE
0uH
L105
1-414-235-22 FERRITE
0uH
L106
1-500-245-11 FERRITE
0uH
L121
1-500-245-11 FERRITE
0uH
L122
1-500-245-11 FERRITE
0uH
L131
1-500-245-11 FERRITE
0uH
L141
1-412-029-11 INDUCTOR CHIP 10uH
L142
1-412-032-11 INDUCTOR CHIP 100uH
L143
1-412-029-11 INDUCTOR CHIP 10uH
L144
1-412-032-11 INDUCTOR CHIP 100uH
L145
1-412-032-11 INDUCTOR CHIP 100uH
L146
1-469-855-21 FERRITE
0uH
L147
1-469-855-21 FERRITE
0uH
L161
1-500-245-11 FERRITE
0uH
L171
1-500-245-11 FERRITE
0uH
L180
1-469-855-21 FERRITE
0uH
L181
1-469-855-21 FERRITE
0uH
L182
1-500-245-11 FERRITE
0uH
L183
1-216-296-11 SHORT
0
L184
1-216-296-11 SHORT
0
< TRANSISTOR >
Q101
8-729-403-35 TRANSISTOR
UN5113
Q121
8-729-403-35 TRANSISTOR
UN5113
Q122
8-729-101-07 TRANSISTOR
2SB798-DL
Q131
8-729-026-53 TRANSISTOR
2SA1576A-T106-QR
Q132
8-729-903-10 TRANSISTOR
FMW1
Q133
8-729-402-93 TRANSISTOR
UN5214
Q134
8-729-402-93 TRANSISTOR
UN5214
Q181
8-729-018-75 FET
2SJ278MY
Q182
8-729-017-65 FET
2SK1764KY
< RESISTOR >
R101
1-216-829-11 METAL CHIP
4.7K
5%
1/16W
R102
1-216-853-11 METAL CHIP
470K
5%
1/16W
R103
1-216-863-11 RES-CHIP
3.3M
5%
1/16W
R104
1-216-853-11 METAL CHIP
470K
5%
1/16W
R105
1-216-825-11 METAL CHIP
2.2K
5%
1/16W
R106
1-216-825-11 METAL CHIP
2.2K
5%
1/16W
R107
1-216-825-11 METAL CHIP
2.2K
5%
1/16W
R108
1-216-833-11 METAL CHIP
10K
5%
1/16W
R109
1-216-845-11 METAL CHIP
100K
5%
1/16W
R110
1-216-845-11 METAL CHIP
100K
5%
1/16W
R111
1-216-833-11 METAL CHIP
10K
5%
1/16W
R112
1-216-829-11 METAL CHIP
4.7K
5%
1/16W
R113
1-216-833-11 METAL CHIP
10K
5%
1/16W
R114
1-216-827-11 METAL CHIP
3.3K
5%
1/16W
R115
1-216-833-11 METAL CHIP
10K
5%
1/16W
R116
1-216-839-11 METAL CHIP
33K
5%
1/16W
R117
1-216-837-11 METAL CHIP
22K
5%
1/16W
R118
1-218-855-11 METAL CHIP
2.2K
0.5%
1/16W
R119
1-218-863-11 METAL CHIP
4.7K
0.5%
1/16W
R120
1-218-889-11 METAL CHIP
56K
0.5%
1/16W
R121
1-218-863-11 METAL CHIP
4.7K
0.5%
1/16W
R122
1-218-855-11 METAL CHIP
2.2K
0.5%
1/16W
R123
1-216-819-11 METAL CHIP
680
5%
1/16W
R124
1-216-809-11 METAL CHIP
100
5%
1/16W
R125
1-216-815-11 METAL CHIP
330
5%
1/16W
R126
1-216-819-11 METAL CHIP
680
5%
1/16W
R127
1-216-845-11 METAL CHIP
100K
5%
1/16W
R128
1-219-724-11 METAL CHIP
1
1%
1/4W
R129
1-216-298-00 METAL CHIP
2.2
5%
1/10W
R130
1-216-829-11 METAL CHIP
4.7K
5%
1/16W
R131
1-216-833-11 METAL CHIP
10K
5%
1/16W
R132
1-216-841-11 METAL CHIP
47K
5%
1/16W
R133
1-216-821-11 METAL CHIP
1K
5%
1/16W
R134
1-216-821-11 METAL CHIP
1K
5%
1/16W
R135
1-216-821-11 METAL CHIP
1K
5%
1/16W
R136
1-216-295-11 SHORT
0
R138
1-216-833-11 METAL CHIP
10K
5%
1/16W
R150
1-216-833-11 METAL CHIP
10K
5%
1/16W
R151
1-216-833-11 METAL CHIP
10K
5%
1/16W
R154
1-216-833-11 METAL CHIP
10K
5%
1/16W
R155
1-216-864-11 METAL CHIP
0
5%
1/16W
R156
1-216-864-11 METAL CHIP
0
5%
1/16W
R157
1-216-809-11 METAL CHIP
100
5%
1/16W
R158
1-216-809-11 METAL CHIP
100
5%
1/16W
R159
1-216-833-11 METAL CHIP
10K
5%
1/16W
R160
1-216-833-11 METAL CHIP
10K
5%
1/16W
R161
1-216-833-11 METAL CHIP
10K
5%
1/16W
R163
1-216-809-11 METAL CHIP
100
5%
1/16W
R164
1-216-809-11 METAL CHIP
100
5%
1/16W
R165
1-216-809-11 METAL CHIP
100
5%
1/16W
R167
1-216-833-11 METAL CHIP
10K
5%
1/16W
R168
1-216-845-11 METAL CHIP
100K
5%
1/16W
R169
1-216-855-11 METAL CHIP
680K
5%
1/16W
R170
1-216-827-11 METAL CHIP
3.3K
5%
1/16W
R171
1-216-821-11 METAL CHIP
1K
5%
1/16W
R173
1-216-821-11 METAL CHIP
1K
5%
1/16W
R174
1-216-811-11 METAL CHIP
150
5%
1/16W
R175
1-216-857-11 METAL CHIP
1M
5%
1/16W
R176
1-216-809-11 METAL CHIP
100
5%
1/16W
R179
1-216-295-11 SHORT
0
R181
1-216-841-11 METAL CHIP
47K
5%
1/16W
R182
1-216-841-11 METAL CHIP
47K
5%
1/16W
R183
1-216-841-11 METAL CHIP
47K
5%
1/16W
R184
1-220-942-11 METAL CHIP
3.3
1%
1/4W
R185
1-220-942-11 METAL CHIP
3.3
1%
1/4W
Ref. No.
Part No.
Description
Remark
Ref. No.
Part No.
Description
Remark
64
MDS-S50
R195
1-216-833-11 METAL CHIP
10K
5%
1/16W
R196
1-216-833-11 METAL CHIP
10K
5%
1/16W
R197
1-216-833-11 METAL CHIP
10K
5%
1/16W
R218
1-216-864-11 METAL CHIP
0
5%
1/16W
< SWITCH >
S101
1-762-596-21 SWITCH, PUSH (1 KEY) (LIMIT IN)
S103
1-771-956-21 SWITCH, PUSH (1 KEY) (PACK OUT)
S104
1-771-955-21 SWITCH, PUSH (1 KEY) (PLAY POSITION)
S105
1-771-955-21 SWITCH, PUSH (1 KEY) (REC POSITION)
**************************************************************
A-4725-597-A DISPLAY BOARD, COMPLETE (US, CND)
A-4725-603-A DISPLAY BOARD, COMPLETE
A-4725-603-A DISPLAY BOARD, COMPLETE
(AEP, UK, HK, AUS)
A-4725-607-A DISPLAY BOARD, COMPLETE (SP)
A-4476-650-A DISPLAY BOARD, COMPLETE (BR, AR)
A-4476-650-A DISPLAY BOARD, COMPLETE (BR, AR)
************************
4-212-590-22 HOLDER (FL)
*
4-949-935-21 CUSHION (FL)
< BUZZER >
BP791
1-504-920-21 BUZZER (EXCEPT US, CND)
< CAPACITOR >
C760
1-164-159-11 CERAMIC
0.1uF
50V
C761
1-162-294-31 CERAMIC
0.001uF
10%
50V
C762
1-162-294-31 CERAMIC
0.001uF
10%
50V
C763
1-162-294-31 CERAMIC
0.001uF
10%
50V
C764
1-164-159-11 CERAMIC
0.1uF
50V
C765
1-126-153-11 ELECT
22uF
20%
6.3V
C766
1-164-159-11 CERAMIC
0.1uF
50V
C769
1-162-215-31 CERAMIC
47PF
5%
50V
C781
1-124-584-00 ELECT
100uF
20%
10V
C782
1-162-306-11 CERAMIC
0.01uF
20%
16V
< CONNECTOR >
CN701
1-779-557-21 CONNECTOR, FFC (LIF (NON-ZIF)) 20P
* CN702
1-691-407-11 CONNECTOR, BOARD TO BOARD 10P
< FLUORESCENT INDICATOR TUBE >
FL771
1-517-986-11 INDICATOR TUBE, FLUORESCENT
< IC >
IC761
8-759-659-03 IC MSM9202-07GS-K
IC781
8-749-013-92 IC GP1UC7X (REMOTE CONTROL RECEIVER)
< TRANSISTOR >
Q767
8-729-900-74 TRANSISTOR
DTC143TS
Q793
8-729-030-02 TRANSISTOR
DTC144ESA
(EXCEPT US, CND)
< RESISTOR >
R702
1-249-421-11 CARBON
2.2K
5%
1/4W
R703
1-247-843-11 CARBON
3.3K
5%
1/4W
R704
1-249-425-11 CARBON
4.7K
5%
1/4W
R705
1-249-429-11 CARBON
10K
5%
1/4W
R712
1-249-421-11 CARBON
2.2K
5%
1/4W
R713
1-247-843-11 CARBON
3.3K
5%
1/4W
R714
1-249-425-11 CARBON
4.7K
5%
1/4W
R715
1-249-429-11 CARBON
10K
5%
1/4W
R760
1-247-807-31 CARBON
100
5%
1/4W
R761
1-247-807-31 CARBON
100
5%
1/4W
R762
1-247-807-31 CARBON
100
5%
1/4W
R763
1-247-807-31 CARBON
100
5%
1/4W
R767
1-249-441-11 CARBON
100K
5%
1/4W
R769
1-247-843-11 CARBON
3.3K
5%
1/4W
R781
1-249-401-11 CARBON
47
5%
1/4W
R782
1-247-807-31 CARBON
100
5%
1/4W
R797
1-249-429-11 CARBON
10K
5%
1/4W
(EXCEPT US, CND)
< SWITCH/ROTARY ENCODER >
S701
1-762-875-21 SWITCH, KEYBOARD (z)
S702
1-762-875-21 SWITCH, KEYBOARD (x)
S703
1-762-875-21 SWITCH, KEYBOARD (M)
S704
1-762-875-21 SWITCH, KEYBOARD (m)
S705
1-762-875-21 SWITCH, KEYBOARD (u)
S711
1-762-875-21 SWITCH, KEYBOARD (MENU/NO)
S712
1-762-875-21 SWITCH, KEYBOARD (YES)
S713
1-475-543-11 ENCODER, ROTARY
(. AMS >, PUSH ENTER)
S714
1-762-875-21 SWITCH, KEYBOARD (CLEAR)
S715
1-762-875-21 SWITCH, KEYBOARD (Z)
**************************************************************
A-4725-596-A MAIN BOARD, COMPLETE (US, CND)
A-4725-602-A MAIN BOARD, COMPLETE (AEP, UK, HK, AUS)
A-4725-606-A MAIN BOARD, COMPLETE (SP)
A-4476-654-A MAIN BOARD, COMPLETE (BR, AR)
A-4725-602-A MAIN BOARD, COMPLETE (AEP, UK, HK, AUS)
A-4725-606-A MAIN BOARD, COMPLETE (SP)
A-4476-654-A MAIN BOARD, COMPLETE (BR, AR)
*********************
7-685-546-19 SCREW +BTP 3X8 TYPE2 N-S
< CAPACITOR >
C1
1-126-964-11 ELECT
10uF
20%
50V
C19
1-164-156-11 CERAMIC CHIP
0.1uF
25V
C26
1-162-964-11 CERAMIC CHIP
0.001uF
10%
50V
C36
1-162-960-11 CERAMIC CHIP
220PF
10%
50V
C37
1-162-960-11 CERAMIC CHIP
220PF
10%
50V
C39
1-164-156-11 CERAMIC CHIP
0.1uF
25V
C48
1-162-927-11 CERAMIC CHIP
100PF
5%
50V
C151
1-164-315-11 CERAMIC CHIP
470PF
5%
50V
C152
1-128-551-11 ELECT
22uF
20%
25V
C153
1-128-551-11 ELECT
22uF
20%
25V
C161
1-164-816-11 CERAMIC CHIP
220PF
2%
50V
C165
1-162-927-11 CERAMIC CHIP
100PF
5%
50V
C166
1-162-927-11 CERAMIC CHIP
100PF
5%
50V
C171
1-137-368-11 MYLAR
0.0047uF 5%
50V
C172
1-130-471-00 MYLAR
0.001uF
5%
50V
C176
1-128-551-11 ELECT
22uF
20%
25V
C177
1-164-315-11 CERAMIC CHIP
470PF
5%
50V
C251
1-164-315-11 CERAMIC CHIP
470PF
5%
50V
C252
1-128-551-11 ELECT
22uF
20%
25V
C253
1-128-551-11 ELECT
22uF
20%
25V
C261
1-164-816-11 CERAMIC CHIP
220PF
2%
50V
C265
1-162-927-11 CERAMIC CHIP
100PF
5%
50V
C266
1-162-927-11 CERAMIC CHIP
100PF
5%
50V
BD DISPLAY MAIN
Click on the first or last page to see other MDS-S50 (serv.man2) service manuals if exist.