K-505TX
Ref. No .
3675
SERVICE MANUAL
STEREO
CASETTE DECK
MODEL K-505TX
R
SAFETY-RELATED COMPONENT WARNING!!
COMPONENTS IDENTIFIED BY MARK
ON THE
CRITICAL FOR RISK OF FIRE AND ELECTRIC SHOCK.
REPLACE THESE COMPONENTS WITH ONKYO
PARTS WHOSE PART NUMBER APPEAR AS SHOWN
IN THIS MANUAL.
MAKE LEAKAGE CURRENT OR RESISTANCE
MEASUREMENTS TO DETERMINE THAT EXPOSED
PARTS ARE ACCEPTABLY INSULATED FROM THE
SUPPLY CIRCUIT BEFORE RETURNING THE
APPLIANCE TO THE CUSTOMER.
SCHEMATIC DIAGRAM AND IN THE PARTS LIST ARE
STEREO CASSETTE TAPE DECK
CASSETTE LOADING MECHANISM
STANDBY/ ON
STANDBY
ALBUM
FADE
DOLBY NR
REV. MODE
COUNTER RESET
REC LEVEL
K-
505X
SUPP,SUPT
SUDT
Silver models
230V AC,50Hz
120V AC,60Hz
052001
Track format
4-tracks, 2-channels
Erasing system
AC erase
Tape speed
4.8 cm/sec.
Wow and flutter
0.1 % (WRMS)
0.2 % (DIN)
Frequency response
Metal position tape
30 to 15,000 Hz ± 3 dB
High position tape
30 to 14,000 Hz ± 3 dB
Normal position tape
30 to 13,000 Hz ± 3 dB
Signal to noise ratio
· 54 dB (metal position tape, Dolby NR
off)
· Noise reduction of 10 dB above 5 kHz
and 5 dB at 1 kHz is possible with Dolby
B NR.
· Noise reduction of 20 dB at 5 kHz is
possible with Dolby C NR.
Input Jacks
LINE IN: 2
Input sensitivity: 80 mV
Input impedance: 50 kohms
Output Jacks
LINE OUT: 2
Standard output level: 500 mV
Output load impedance:
over 50 kohms
Motors
DC servo motor: 1
Heads
REC/PB: Special Hard Permalloy: 1
Erase head: Ferrite: 1
Power supply rating
AC 230-240 V, 50 Hz
AC 120 V, 60 Hz
Power consumption
12 W (230-240 V, 50 Hz)
14 W (120 V, 60 Hz)
Dimensions
205 mm × 76 mm × 278 mm
(Width × Height × Depth)
Weight
2.6 kg
Specifications and external appearance are
subject to change without notice as a result of
product improvement.
1. Replacing the fuse
This symbol located near the fuses indicates that the
fuse used is fast operating type. For continued protection against
fire hazard, replace with same type fuse. For fuse rating refer to
the marking adjacent to the symbol.
Ce symbole indique que le fusible utlise est a rapide.
Pour une protection permanente, n'untiliser que fusibles de
meme type. Ce darnier est la qu le present symbol est
appse.
CIRCUIT NO.
PART NO.
DESCRIPTION
F901
252074
2A-SE-EAK,Fuse
SERVICE PROCEDURES
SPECIFICATIONS
K-505TX
BLOCK DIAGRAM
Q101
Q103.Q104
R115.R116
Q102
P.B.AMP.
P.B. LEVEL
Q201
DOLBY NR. REC EQ. METER AMP
DISPLAY
Q709
KEY CONTROL
MECHA AND DRIVER
TAPE
SPEED
R716
S717
AUTO
ADJUSTMENT
START KEY
MICROPROCESSOR
Q701
Q905
5V
(for MICROPROCESSOR)
Q901
Q903
Q906
12V(for SIGNAL)
12V(for MECHA)
-22V(for F.L. TUBE)
D901.D902
T901
D905.D906
POWER TRANSFORMER
AND REGULATOR
Q401-Q405
L401.L402.L403
BIAS OSC AND HX PRO
ERASE
HEAD
R/P
HEAD
IN
OUT
LINE
70/120
K-505TX
U1
U2
P101
T901
U3
U5
Z001
P705
P702
P902A
U6
U4
P703
EXPLODED VIEW
F901
K-505TX
REF.NO.PART NO.
DESCRIPTION
1
27100334A
Chassis
2
27175323
Leg
3
27175325
Leg
4
838130088
3TTB+8B.Self tapping screw
5
27190897
KGLS-3S.Holder
6
27301394
HL-18-0.Clamp
7
27191045
KGPS-3.5S.Holder
8
28140020
9
830440069
4TTC+6C(BC).Self tapping screw
10
27150407B
Shield plate
11
27300750
S-RELIEF #2271.Bushing cord
12
27191137
ML Holder
13
27191138
MR Holder
14
833130100
3TTP+10P.Self tapping screw
15
27122849
Rear panel
16
838430088
3TTB+8B(BC).Self tapping screw
17
27111214
Front bracket
18
28141456
Cushion
19
27212314
Front panel
20
28135247Y
Badge
21
28198864
Facet
23
28191796A
Clear plate
24
28184795
Cover
25
28141470
Cushion
26
838930088
3TTB+8B(UN).Self tapping screw
27
28148476
(TRAY).Door
P101
2009990659
NSAS-14P0919.Socket AS
P702
20022392635ANSAS-26P0918.Socket AS
P703
2009990469
NSAS-10P0623.Socket AS
P705
204319013
NCFC3-19013.F.F.C
P902A 253193HIT
AS-CEE. Power supply cord <P>
253277MIL
AS-UC-2#18.Poewr supply cord <D>
T901
2301298
NPT-1314P.Power transformer <P>
2301297
NPT-1314D.Power transformer <D>
U1
1N281546-1A NAAR-7146-1A.Main cuircuit PC board ass'y <D>
1N281546-1B NAAR-7146-1B,Main circuit PC board ass'y <P>
U2
1N281547-1A NAAF-7147-1A,Playback amp. PC board ass'y <D>
1N281547-1B NAAF-7147-1B,Playback amp. PC board ass'y <P>
U3
1N281548-1A NAAF-7148-1A,Dolby circuit PC board ass'y <D>
1N281548-1B NAAF-7148-1B,Dolby circuit PC board ass'y <P>
U4
1N281549-1A NAAF-7149-1A,Recording amp. PC board ass'y <D>
1N281549-1B NAAF-7149-1B,Recording amp. PC board ass'y <P>
U5
1N281550-1A NAPS-7150-1A,Power transformer PC board ass'y <D>
1N281550-1B NAPS-7150-1B,Power transformer PC board ass'y <P>
U6
1N281551-1A NADIS-7151-1A,Display circuit PC board ass'y <D>
1N281551-1B NADIS-7151-1B,Display circuit PC board ass'y <P>
Z001
244247
CMAL2Z7.Deck mechanism
F901
252074
2A-SE-EAK,Fuse <European model only>
PARTS LIST
K-505TX