Ref.
No.
3420
ONKYO
SERVICE
MANUAL
QUARTZ
SYNTHESIZED
TUNER
AMPLIFIER
MODEL
TX-7900
MODEL
TX-7920
Black
and
Silver
models
SAFETY-RELATED
COMPONENT
WARNING!
!
COMPONENTS
IDENTIFIED
BY
MARK
A
ON
THE
SCHEMATIC
DIAGRAM
AND
IN
THE
PARTS
LIST
ARE
CRITICAL
FOR
RISK
OF
FIRE
AND
ELECTRIC
SHOCK.
REPLACE
THESE
COMPO-
NENTS
WITH
ONKYO
PARTS
WHOSE
PART
NUMBERS
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.
ONKYO
AUDIO
COMPONENTS
TABLE
OF
CONTENTS
Specifications
eee
errr
ee
eee
eee
eee
ee
eee
Tee
eee
eee
eee
ere
Terre
ree
eee
ere
2
Service
procedures::+++i+sssssssstssesesesseeesseeseseeseserseeageeens
3
Exploded
view
Model
TX-7920++:+++:+++s+sssesseseseeeeseeessseeneens
4
Parts
Ist
Model
TX-7920
tse:
wvesncwses
ceracmmamninsaeennenee
5
Exploded
view
Model
TX-7900++++++++++:ssess+sessesesseeereeesaeeens
6
Parts
list
Model
‘TX-7900
issssster<eomnns
sane
venwavanes
senna
canon
cones
7
Block
diagram
Model
TX-7920-++++1:+++ssessseerseeesseersese
seeeees
8
Block
diagram
Model
TX-7900-+++++:++1s+sessseerseseseeteseeeeeeeens
9
IC
block
diagram
and
descriptions::::::1++++sseeeseseeseeseerees
10
Packing
view
svrcessscessceeeseeessseeseessenseneeseesesescnesensereanneens
17
Adjustment
procedures
ree
eee
eee
eee
er
errr)
18
Printed
circuit
board
view
from
bottom
side-+r+++++rrr
+
est+*
21
Schematic
diagram
Model
"P7920:
sere:
ose
cwaes
uedewvensaes
eonnenamenaee
eemaseeeninenl
23
Model
TX:
7900»
«sss
sentecnnsaxonenen
nonce
dvtineanennasaerawargicaeenines
25
Printed
circuit
board-parts
list
Model
“TX.
7620
se2nesenses
ary
deanwians
sccswansapanvagis
narangianane
gies
sen
29
Model
1X.
20
0Gxrtceswens
corweswaieaee
dennwonatennigipien
vpeiciirnay
9
tate
wea
39
TX-7900/TX-7920