Panasonic WV-PS154 / WV-PS15 Service Manual ▷ View online
– 14 –
EXPLODED VIEW OF WV-PS15
2
3
1
1
1
1
Q135
M17
M15
E5
M5
M16
M17
M2
M4
M7
E10
E100
M6
PACKAGING
M23
M25
M23
M25
M25
M21
M8
M10
M9
M1
Serial No. Label
M11
M4
M3
PCB1
M18
PCB2
M19
D1
E11
F100
M5
6
6
6
6
6
6
6
7
WV-PS15
M13
M14
4
5
Earth Lug
○
Numbers show Screws
No.
Screws
Description
q
XSB3+8FX
Binding Head Machine Screw
w
XTN3+10CFN
Pan Head Tapping Screw
e
XYM4+E8FN
Binding Head Screw and Washer Assy
r
XYN4+J8FN
Pan Head Screw and Washer Assy
t
XWC4BFN
Internal Toothed Lock Washer
y
YWA1AA0272A4
Speacial Screw
u
YWA1AC0272A4
Speacial Screw
WV-PS154/WV-PS15
WV-PS154/WV-PS15
E1
YWVAR2
Connector Cover
MO1
!
L6FAHDCH0004
DC Motor
E101
!
YWGBSXBS
AC Power Cord Assy for WV-PS154/B
!
YWACF250G
AC Power Cord Assy for WV-PS154/G
M1
V5WB2566A2
Front Panel
M2
YWA5RG0141A3
Power Switch Knob
M3
!
YWV5CA0504B2
Card Holder
M4
V2KA1301A1
Front Chassis
M5
!
V2PA1236B3
Insulator Plate
M6
YW2J08
Support
M7
!
V2PA1235A3
Insulator Sheet Cover
M8
YW0920
Tact
M9
!
V2PA1237A3
Insulator Sheet B
M10
!
V2PA1238A3
Insulator Sheet C
M11
V2SA4842A3
Mounting Angle
M12
V5EA2421A1
Upper Cover
M13
V5WC2567A1
Rear Panel
M14
!
YWSR5N4
Cord Clamp
M15
YWCKT10V0
Cord Clamp
M16
YWA7SA0689A4
Earth Label
M17
V2KA1300A1
Main Chassis
M18
YWV5LA0067A4
Rubber Foot
M19
YWA2LA0070A4
Joint
M21
YWV1AA1074A4
Standard Screw
M22
YWA1AA0272A4
Special Screw
M30
!
V7QA5387A4
Main Label for WV-PS154/B
!
V7QA5386A4
Main Label for WV-PS154/G
M32
YFV7MB0099A4
Caution Label
PCB1(RTL)
VP154EKZ1AYP
Printed Circuit Board Assy
IC1
NJM78L05A
IC
IC2
C0BBBA000023
IC
IC3
C0ABBB000096
IC
IC4
YWMCHC4060E
IC
IC5
YWMCHC74AE
IC
IC6
C0JBAC000186
IC
IC100
C0DBAZG00007
IC
IC101
YWTA7303P
IC
IC102
C0ABBB000096
IC
IC103
C0JBAB000259
IC
IC107
C0JBAE000086
IC
IC108
YWTC7W08F
IC
IC109
C0JBAB000171
IC
IC112,113
YWMCHC00AE
IC
IC114
YWMCHC08AE
IC
IC115
YWMCHC04AE
IC
IC116
C0JBAK000126
IC
IC117
C0ABBB000096
IC
IC300
C0DBAZG00007
IC
IC301
YWTA7303P
IC
IC302
C0ABBB000096
IC
IC303
C0JBAB000259
IC
IC307
C0JBAE000086
IC
IC308
YWTC7W08F
IC
IC309
C0JBAB000171
IC
IC312,313
YWMCHC00AE
IC
IC314
YWMCHC08AE
IC
IC315
YWMCHC04AE
IC
IC316
C0JBAK000126
IC
IC317
C0ABBB000096
IC
IC500
C0DBAZG00007
IC
IC501
YWTA7303P
IC
IC502
C0ABBB000096
IC
IC503
C0JBAB000259
IC
IC507
C0JBAE000086
IC
IC508
YWTC7W08F
IC
IC509
C0JBAB000171
IC
IC512,513
YWMCHC00AE
IC
IC514
YWMCHC08AE
IC
IC515
YWMCHC04AE
IC
IC516
C0JBAK000126
IC
IC517
C0ABBB000096
IC
IC700
C0DBAZG00007
IC
IC701
YWTA7303P
IC
REF. NO.
PART NO.
DESCRIPTION
REF. NO.
PART NO.
DESCRIPTION
– 15 –
REPLACEMENT PARTS LIST
Important Notice
1.
Components identified by "
!
" mark have special characteristics important for safety.
When replacing any of these components, use only manufacturer's specified parts.
2.
RTL : Retention Time Limited (No longer available after discontinuing product).
MAIN BOARD
MISCELLANEOUS
CAMERA DRIVE UNIT WV-PS154
IC702
C0ABBB000096
IC
IC703
C0JBAB000259
IC
IC707
C0JBAE000086
IC
IC708
YWTC7W08F
IC
IC709
C0JBAB000171
IC
IC712,713
YWMCHC00AE
IC
IC714
YWMCHC08AE
IC
IC715
YWMCHC04AE
IC
IC716
C0JBAK000126
IC
IC717
C0ABBB000096
IC
Q1,2
2SC2412K-T46
Transistor
Q3
B1ABGD000010
Transistor
Q4-7
2SA1037K-T47
Transistor
Q8
B1ADBD000005
Transistor
Q9,10
2SA1037K-T47
Transistor
Q11,12
2SC2412K-T46
Transistor
Q100
2SB0941AJ
Transistor
Q101-105
2SC2412K-T46
Transistor
Q106
2SC3837KT47
Transistor
Q107-111
2SC2412K-T46
Transistor
Q112
B1ABGD000010
Transistor
Q113
2SC3837KT47
Transistor
Q114
B1ABGD000010
Transistor
Q115-120
2SC2412K-T46
Transistor
Q121
B1ABGD000010
Transistor
Q122-124
2SC2412K-T46
Transistor
Q125
B1ABGD000010
Transistor
Q126
2SC2412K-T46
Transistor
Q127
B1ABGD000010
Transistor
Q128,129
2SC2412K-T46
Transistor
Q130
B1GBHBGA0001
Transistor
Q131-134
2SC2412K-T46
Transistor
Q135-149
2SA1037K-T47
Transistor
Q150
2SC2412K-T46
Transistor
Q300
2SB0941AJ
Transistor
Q301-305
2SC2412K-T46
Transistor
Q306
2SC3837KT47
Transistor
Q307-311
2SC2412K-T46
Transistor
Q312
B1ABGD000010
Transistor
Q313
2SC3837KT47
Transistor
Q314
B1ABGD000010
Transistor
Q315-320
2SC2412K-T46
Transistor
Q321
B1ABGD000010
Transistor
Q322-324
2SC2412K-T46
Transistor
Q325
B1ABGD000010
Transistor
Q326
2SC2412K-T46
Transistor
Q327
B1ABGD000010
Transistor
Q328,329
2SC2412K-T46
Transistor
Q330
B1GBHBGA0001
Transistor
Q331-334
2SC2412K-T46
Transistor
Q335-349
2SA1037K-T47
Transistor
Q350
2SC2412K-T46
Transistor
Q500
2SB0941AJ
Transistor
Q501-505
2SC2412K-T46
Transistor
Q506
2SC3837KT47
Transistor
Q507-511
2SC2412K-T46
Transistor
Q512
B1ABGD000010
Transistor
Q513
2SC3837KT47
Transistor
Q514
B1ABGD000010
Transistor
Q515-520
2SC2412K-T46
Transistor
Q521
B1ABGD000010
Transistor
Q522-524
2SC2412K-T46
Transistor
Q525
B1ABGD000010
Transistor
Q526
2SC2412K-T46
Transistor
Q527
B1ABGD000010
Transistor
Q528,529
2SC2412K-T46
Transistor
Q530
B1GBHBGA0001
Transistor
Q531-534
2SC2412K-T46
Transistor
Q535-549
2SA1037K-T47
Transistor
Q550
2SC2412K-T46
Transistor
Q700
2SB0941AJ
Transistor
Q701-705
2SC2412K-T46
Transistor
Q706
2SC3837KT47
Transistor
Q707-711
2SC2412K-T46
Transistor
Q712
B1ABGD000010
Transistor
Q713
2SC3837KT47
Transistor
Q714
B1ABGD000010
Transistor
Q715-720
2SC2412K-T46
Transistor
Q721
B1ABGD000010
Transistor
Q722-724
2SC2412K-T46
Transistor
Q725
B1ABGD000010
Transistor
Q726
2SC2412K-T46
Transistor
Q727
B1ABGD000010
Transistor
Q728,729
2SC2412K-T46
Transistor
Q730
B1GBHBGA0001
Transistor
Q731-734
2SC2412K-T46
Transistor
Q735-749
2SA1037K-T47
Transistor
Q750
2SC2412K-T46
Transistor
D1-3
B0ADCJ000008
Diode
D100
B0JCMG000003
Diode
D101
B0BA5R000004
Diode
D102,103
B0ADCJ000008
Diode
D104
B0ADCJ000015
Diode
D105-110
B0ADCJ000008
Diode
D111
B0BA5R000004
Diode
D112
B0BA01500003
Diode
D113
B0ADCJ000015
Diode
D114,115
B0ADCJ000008
Diode
D300
B0JCMG000003
Diode
D301
B0BA5R000004
Diode
D302,303
B0ADCJ000008
Diode
D304
B0ADCJ000015
Diode
D305-310
B0ADCJ000008
Diode
D311
B0BA5R000004
Diode
D312
B0BA01500003
Diode
D313
B0ADCJ000015
Diode
D314,315
B0ADCJ000008
Diode
D500
B0JCMG000003
Diode
D501
B0BA5R000004
Diode
D502,503
B0ADCJ000008
Diode
REF. NO.
PART NO.
DESCRIPTION
REF. NO.
PART NO.
DESCRIPTION
– 16 –
D504
B0ADCJ000015
Diode
D505-510
B0ADCJ000008
Diode
D511
B0BA5R000004
Diode
D512
B0BA01500003
Diode
D513
B0ADCJ000015
Diode
D514,515
B0ADCJ000008
Diode
D700
B0JCMG000003
Diode
D701
B0BA5R000004
Diode
D702,703
B0ADCJ000008
Diode
D704
B0ADCJ000015
Diode
D705-710
B0ADCJ000008
Diode
D711
B0BA5R000004
Diode
D712
B0BA01500003
Diode
D713
B0ADCJ000015
Diode
D714,715
B0ADCJ000008
Diode
R2-4
RRJ6GEYJ392V
Metal
3.9K ohms 1/10W
R5
D0GD682JA003
Metal
6.8K ohms 1/10W
R6
D0GD123JA003
Metal
12K ohms 1/10W
R7
D0GD682JA003
Metal
6.8K ohms 1/10W
R8
D0GD223JA003
Metal
22K ohms 1/10W
R14
D0GD103JA003
Metal
10K ohms 1/10W
R15
RRJ6GEYJ105V
Metal
1M ohms 1/10W
R16
D0GD223JA003
Metal
22K ohms 1/10W
R17
D0GD103JA003
Metal
10K ohms 1/10W
R18
D0GD223JA003
Metal
22K ohms 1/10W
R19
D0GD103JA003
Metal
10K ohms 1/10W
R20
RRJ6GEYJ333V
Metal
33K ohms 1/10W
R21
D0GD272JA003
Metal
2.7K ohms 1/10W
R22
D0GD223JA003
Metal
22K ohms 1/10W
R23
D0GD222JA003
Metal
2.2K ohms 1/10W
R24
RRJ6GEYJ330V
Metal
33 ohms 1/10W
R25
D0GD222JA003
Metal
2.2K ohms 1/10W
R26
RRJ6GEYJ333V
Metal
33K ohms 1/10W
R27
D0GD224JA003
Metal
220K ohms 1/10W
R28
D0GD154JA003
Metal
150K ohms 1/10W
R29
YWR10EZHJ750
Carbon
75 ohms 1/10W
R30
D0GD680JA003
Metal
68 ohms 1/10W
R31
D0GD103JA003
Metal
10K ohms 1/10W
R32
D0GD102JA003
Metal
1K ohms 1/10W
R33
D0GD103JA003
Metal
10K ohms 1/10W
R34
YWR1220P333D
Metal
33K ohms
R35,36
YWR1220P102D
Metal
1K ohms
R37
RRJ6GEYJ565V
Metal
5.6M ohms 1/10W
R38
RRJ6GEYJ564V
Metal
560K ohms 1/10W
R39
D0GD103JA003
Metal
10K ohms 1/10W
R40
RRJ6GEYJ104V
Metal
100K ohms 1/10W
R41,42
YWR1220Q100D
Metal
10 ohms
R43
D0GD103JA003
Metal
10K ohms 1/10W
R44
D0GD473JA003
Metal
47K ohms 1/10W
R45
D0GD472JA003
Metal
4.7K ohms 1/10W
R46
RRJ6GEYJ561V
Metal
560 ohms 1/10W
R47
ERDS2TJ220T
Carbon
22 ohms 1/10W
R100
YWERX2SJ3R3P
Metal
3.3 ohms
R101
D0GD273JA003
Metal
27K ohms 1/10W
R102
D0GD223JA003
Metal
22K ohms 1/10W
R103
D0GD103JA003
Metal
10K ohms 1/10W
R104
YWR1220P223D
Metal
22K ohms
R106
YWR1220P332D
Metal
3.3K ohms
R107,108
D0GD102JA003
Metal
1K ohms 1/10W
R109
D0GD223JA003
Metal
22K ohms 1/10W
R110
YWR1220P332D
Metal
3.3K ohms
R111
RRJ6GEYJ332V
Metal
3.3K ohms 1/10W
R112
D0GD103JA003
Metal
10K ohms 1/10W
R113
D0GD432JA003
Carbon
4.3K ohms 1/10W
R114
D0GD683JA003
Metal
68K ohms 1/10W
R115
D0GD222JA003
Metal
2.2K ohms 1/10W
R116
RRJ6GEYJ105V
Metal
1M ohms 1/10W
R117
D0GD101JA003
Metal
100 ohms 1/10W
R118
D0GD103JA003
Metal
10K ohms 1/10W
R119
RRJ6GEYJ333V
Metal
33K ohms 1/10W
R120
D0GD103JA003
Metal
10K ohms 1/10W
R121
D0GD102JA003
Metal
1K ohms 1/10W
R122
RRJ6GEYJ333V
Metal
33K ohms 1/10W
R123
D0GD913JA003
Metal
91K ohms 1/10W
R124
D0GD103JA003
Metal
10K ohms 1/10W
R125
RRJ6GEYJ333V
Metal
33K ohms 1/10W
R126
RRJ6GEYJ153V
Metal
15K ohms1/10W
R127
D0GD222JA003
Metal
2.2K ohms 1/10W
R128
D0GD123JA003
Metal
12K ohms 1/10W
R129
D0GD222JA003
Metal
2.2K ohms 1/10W
R130
D0GD103JA003
Metal
10K ohms 1/10W
R131
D0GD102JA003
Metal
1K ohms 1/10W
R132
RRJ6GEYJ333V
Metal
33K ohms 1/10W
R133,134
D0GD102JA003
Metal
1K ohms 1/10W
R135
RRJ6GEYJ330V
Metal
33 ohms 1/10W
R136
D0GD472JA003
Metal
4.7K ohms 1/10W
R137
D0GD154JA003
Metal
150K ohms 1/10W
R138
RRJ6GEYJ331V
Metal
330 ohms 1/10W
R139
D0GD822JA003
Metal
8.2K ohms 1/10W
R140
RRJ6GEYJ331V
Metal
330 ohms 1/10W
R141
RRJ6GEYJ471V
Metal
470 ohms 1/10W
R142
RRJ6GEYJ331V
Metal
330 ohms 1/10W
R143
RRJ6GEYJ332V
Metal
3.3K ohms 1/10W
R144
D0GD123JA003
Metal
12K ohms 1/10W
R145
D0GD223JA003
Metal
22K ohms 1/10W
R146
RRJ6GEYJ332V
Metal
3.3K ohms 1/10W
R147
YWR1220P161D
Metal
160 ohms
R148
D0GD103JA003
Metal
10K ohms 1/10W
R149
YWR10EZHJ622
Carbon
6.2K ohms 1/10W
R150
D0GD101JA003
Metal
100 ohms 1/10W
R151
D0GD102JA003
Metal
1K ohms 1/10W
R152
D1BD62010001
Metal
6.2K ohms
R153
D0GD472JA003
Metal
4.7K ohms 1/10W
R154
D0GD101JA003
Metal
100 ohms 1/10W
R155
D0GD103JA003
Metal
10K ohms 1/10W
R156
D1BD15010001
Metal
1.5Kohms
R157
RRJ6GEYJ331V
Metal
330 ohms 1/10W
R158
D0GD222JA003
Metal
2.2K ohms 1/10W
R159
YWR1220P102D
Metal
1K ohms
R160
D0GD122JA003
Metal
1.2K ohms 1/10W
REF. NO.
PART NO.
DESCRIPTION
REF. NO.
PART NO.
DESCRIPTION
– 17 –
WV-PS154/WV-PS15
R161
D1BD20000001
Metal
20 ohms
R162
D0GD103JA003
Metal
10K ohms 1/10W
R163
D0GD472JA003
Metal
4.7K ohms 1/10W
R164
RRJ6GEYJ681V
Metal
680 ohms 1/10W
R165
YWR1220P302D
Metal
3K ohms
R166
YFR1220P222D
Metal
2.2K ohms
R167
YWR1220P391D
Metal
390 ohms
R168
R10EZHJ363
Carbon
36K ohms 1/10W
R169
D0GD472JA003
Metal
4.7K ohms 1/10W
R170
YFR1220P392D
Metal
3.9K ohms
R171
YWR10EZHJ202
Carbon
2 K ohms 1/10W
R172
D0GD273JA003
Metal
27K ohms 1/10W
R173
YWR1220P102D
Metal
1K ohms
R174
D0GD103JA003
Metal
10K ohms 1/10W
R175
D0GD123JA003
Metal
12K ohms 1/10W
R176
RRJ6GEYJ201V
Carbon
200 ohms 1/10W
R177
D0GD682JA003
Metal
6.8K ohms 1/10W
R178
R10EZHJ511
Carbon
510 ohms 1/10W
R179
D0GD103JA003
Metal
10K ohms 1/10W
R180
YWR1220P562D
Metal
5.6K ohms
R181
D0GD222JA003
Metal
2.2K ohms 1/10W
R182
D0GD682JA003
Metal
6.8K ohms 1/10W
R183
D0GD391JA003
Metal
390 ohms 1/10W
R184
D0GD103JA003
Metal
10K ohms 1/10W
R185
D0GD122JA003
Metal
1.2K ohms 1/10W
R186
YWR10EZHJ132
Carbon
1.3K ohms 1/10W
R187
D0GD103JA003
Metal
10K ohms 1/10W
R188
D0GD102JA003
Metal
1K ohms 1/10W
R189
RRJ6GEYJ561V
Metal
560 ohms 1/10W
R190
D0GD472JA003
Metal
4.7K ohms 1/10W
R191
D0GD151JA003
Metal
150 ohms 1/10W
R192
RRJ6GEYJ332V
Metal
3.3K ohms 1/10W
R193
D0GD472JA003
Metal
4.7K ohms 1/10W
R194
RRJ6GEYJ471V
Metal
470 ohms 1/10W
R195
D0GD472JA003
Metal
4.7K ohms 1/10W
R196
D0GD101JA003
Metal
100 ohms 1/10W
R197
RRJ6GEYJ471V
Metal
470 ohms 1/10W
R198
D0GD682JA003
Metal
6.8K ohms 1/10W
R199
D0GD122JA003
Metal
1.2K ohms 1/10W
R200
D0GD101JA003
Metal
100 ohms 1/10W
R201
RRJ6GEYJ560V
Metal
56 ohms 1/10W
R203
D0GD102JA003
Metal
1K ohms 1/10W
R204
D0GD223JA003
Metal
22K ohms 1/10W
R205
D0GD102JA003
Metal
1K ohms 1/10W
R207
D0GD122JA003
Metal
1.2K ohms 1/10W
R208
RRJ6GEYJ330V
Metal
33 ohms 1/10W
R209
RRJ6GEYJ221V
Metal
220 ohms 1/10W
R210
D0GD103JA003
Metal
10K ohms 1/10W
R211
RRJ6GEYJ332V
Metal
3.3K ohms 1/10W
R212
D0GD123JA003
Metal
12K ohms 1/10W
R213
D0GD682JA003
Metal
6.8K ohms 1/10W
R214
RRJ6GEYJ332V
Metal
3.3K ohms 1/10W
R215
D0GD472JA003
Metal
4.7K ohms 1/10W
R216
RRJ6GEYJ392V
Metal
3.9K ohms 1/10W
R217
D0GD102JA003
Metal
1K ohms 1/10W
R218
RRJ6GEYJ105V
Metal
1M ohms 1/10W
R219
D0GD472JA003
Metal
4.7K ohms 1/10W
R220
RRJ6GEYJ332V
Metal
3.3K ohms 1/10W
R221
D0GD102JA003
Metal
1K ohms 1/10W
R222,223
D0GD222JA003
Metal
2.2K ohms 1/10W
R224,225
D0GD103JA003
Metal
10K ohms 1/10W
R226
YWR1220P911D
Metal
910 ohms
R227
YFR1220P392D
Metal
3.9K ohms
R228
YWR1220P223D
Metal
22K ohms
R229,230
YWR1220P102D
Metal
1K ohms
R231
YFR1220P222D
Metal
2.2K ohms
R232
YWR1220P302D
Metal
3K ohms
R233
YWR1220P512D
Metal
5.1K ohms
R234
YWR1220P161D
Metal
160 ohms
R235
YWR1220P182D
Metal
1.8K ohms
R236
YWR1220P272D
Metal
2.7K ohms
R237
YWR1220P511D
Metal
510 ohms
R238
R1220P821D
Metal
820 ohms
R239
D1BD15000001
Metal
150 ohms
R241
RRJ6GEYJ331V
Metal
330 ohms 1/10W
R242
D0GD102JA003
Metal
1K ohms 1/10W
R243
D0GD103JA003
Metal
10K ohms 1/10W
R244,245
D0GD472JA003
Metal
4.7K ohms 1/10W
R246
D0GD103JA003
Metal
10K ohms 1/10W
R248
RRJ6GEYJ104V
Metal
100K ohms 1/10W
R250
D0GD432JA003
Carbon
4.3K ohms 1/10W
R251
D1BD18000001
Metal
18 ohms 1/10W
R252
D1BD13000001
Metal
13 ohms 1/10W
R300
YWERX2SJ3R3P
Metal
3.3 ohms 1/10W
R301
D0GD273JA003
Metal
27K ohms 1/10W
R302
D0GD223JA003
Metal
22K ohms 1/10W
R303
D0GD103JA003
Metal
10K ohms 1/10W
R304
YWR1220P223D
Metal
22K ohms
R306
YWR1220P332D
Metal
3.3K ohms
R307,308
D0GD102JA003
Metal
1K ohms 1/10W
R309
D0GD223JA003
Metal
22K ohms 1/10W
R310
YWR1220P332D
Metal
3.3K ohms
R311
RRJ6GEYJ332V
Metal
3.3K ohms 1/10W
R312
D0GD103JA003
Metal
10K ohms 1/10W
R313
D0GD432JA003
Carbon
4.3K ohms 1/10W
R314
D0GD683JA003
Metal
68K ohms 1/10W
R315
D0GD222JA003
Metal
2.2K ohms 1/10W
R316
RRJ6GEYJ105V
Metal
1M ohms 1/10W
R317
D0GD101JA003
Metal
100 ohms 1/10W
R318
D0GD103JA003
Metal
10K ohms 1/10W
R319
RRJ6GEYJ333V
Metal
33K ohms 1/10W
R320
D0GD103JA003
Metal
10K ohms 1/10W
R321
D0GD102JA003
Metal
1K ohms 1/10W
R322
RRJ6GEYJ333V
Metal
33K ohms 1/10W
R323
D0GD913JA003
Metal
91K ohms 1/10W
R324
D0GD103JA003
Metal
10K ohms 1/10W
R325
RRJ6GEYJ333V
Metal
33K ohms 1/10W
R326
RRJ6GEYJ153V
Metal
15K ohms1/10W
R327
D0GD222JA003
Metal
2.2K ohms 1/10W
R328
D0GD123JA003
Metal
12K ohms 1/10W
REF. NO.
PART NO.
DESCRIPTION
REF. NO.
PART NO.
DESCRIPTION
– 18 –
WV-PS154/WV-PS15
Click on the first or last page to see other WV-PS154 / WV-PS15 service manuals if exist.