Fisher 400 Service Manual 48001 1

Page 1

Serial Nos, Beginning 4

Service Manual

AL Pugliese

The Fisher Doctor

Fisher Radio Corporation

27 Daleham Street
Staten Island , NY 10308

i

THE

Page 2

is ,,

TROUBLESHOOTING GUIDE |

mas not ya on (piloc or am lumps do no! Iighl).

Chezk: I Fuse F1.
AC plug and line card.
a Wall ml.
C Powar switch 56 (use was! lamp In AC OUTLET an rem a! chassis).

Fuse blows as seen us replaced,

Check; 0 CR1,CR2,CR3;C56,CS7C,C60,C63 in power supplyl
0 C43, 015, cu, CA9,C6261Iamambypass (apoclvors.

Disvorrian (lml. channels) In any posifian al SELECTOR switch.

Hum, Weak at

No oudiuouvpuv o Sel BALANCE, TREBLE ana anss annuals m NORMAL.

o Ramnv: plugs hum reancnassis RCRDR OUT and TAPE MON mks.
0 Remove plugs irom SPACEXPANDER iacks and inset! .unwans (a mus').
a Remava plugs from reavchussis PHONO, TAPE HEAD and Aux Incks.

Tan: O VII), VII or subslilue, (Filament leakage veal [or hum _ gas M52501 dishwfian.)
0 Supply vallaga an CR2, csa, R4); C56, cs7c, R4 c579, R42, R43; csrn, R42;
C520,R40,RAHCSIC,R39,R10;C525,R38, R3 c5. R33, R38
. Bias SUppy vallngn, m; CR1, caOA,Csoa;c41.R34, R35.
0 DC Filamenl-supply vallage,

Dismnion (LEFT channel only) in any pashian al SELECTOR.
Hum, Weak al-
No Audla ovlpu! o Ramuve plugs ham rear-chassis RCRDR OUT and TAPE MON .ncks (1:5! channnl).

- Remove plug Ivan. SPACEXPANDER .ack (leFv channel) and Insert iumpet (a musV),

Chan Po: an a! BALANCE, TREBLE and BASS contro|s lse' Ia NORMAL pcsihons).
o Pasman cl PHASE INVERTER ADJI (RIM).
Tcsl: I V12, VIA, VIS of subsvivutca (Filamanv leakage lesl (av hum _ gas '=sf Io!
dislanian.)
9, o Voltages a! sackzls for VIO, VII, V12, v14, VI5.
Dlscanion (RIGHT channel only) in any posillan of SELECTOR.
Hum, Weak or
Na audio ouvpu' o REMOVE plugs Iran. mar-chassis RCRDR OUT and TAPE MON lacks (right zhannal).
. Remove plug ham SPACEXFANDER iaek (light channel) and insert jumper (a musl).
Check: 0 Pa n o' BALANCE, TREBLE and BASS tunnels (set In NORMAL posirIans).
C Posirzan of PHASE INVERTER ADJ. (R108).
Test: ' VI3, V16, VI7 a: subslllula. (Fllumznl leakage zeal Iar hum-gas V25! [or discarlian).
I anvages at sockars (m vlo, VII, VI3, V16, V17.
Dlsraninn (LEFT channel only) PHONO and TAPE HEAD Pasnlans ol SELECTOR,
Hum, Weak of
Na audio ampul 0 Remove plugs (ram veal-chasm: PHDNO and TA PE HEAD lacks (Yo! ham)
0 Swivzh LEFT channel plug ta RIGHT channel ,nak (lo. durumnn, weak or I'D
audla oulpulL
Cha a Phone camidga, a.- 'npa head eulpu'.
T=sn - VB :7! subsmum (Filament leakage vest fur hum-gas res? For dIslanian.)
Disloniun (RIGHT channel only) PHONO and TAPE HEAD posiiions a6 SELECTOR.
Hm, Week or
No audla mm! C Remove p'ug5 Imnn mar-chassis PHoNc and TAPE HEAD JACKS (Var hum].
a swan RIGHT channel plug va LEFT chenne| iack, (la. dislon.on, weak or no
audla aulpmy.
Chuck: Jazk, plugs and llneraannannng cables.
0 Phone ceruidgc, a! lap: head aulpul.
Te: 0 Va or subslilave. (Fllumnl leakage luv lay hum-gas (05! [av amauianq
Distonion (BOTH channels) all FM posnians of SELECTOR.
Hum, Weak ov
Na audio mnpul - Tune In ulhzr FM slaliens-waich Vuning lndiaarar.
Check: 0 Antenna paslnan and ccnnc 0 IF and RF cIignmanl.
Tcsi: 0 VI, V2, V3, VA, V5, Va or suhs'llure.
o (Fllamanl |eukug= lei! Ian hum-gas Ixsl Ia. dISVOlVIDn.)
o Vuhuges m sockeva Ia: VI, V2, V3, V4, V5, V6 and rulio aalaacar.
Dlstorlion (BOTH channels) FM STEREO pasitians cl SELECTOR only.
0 Tune la ovher FM-SIercnsIulions-wclzh 'uning lndlculor.
Check: . Arflenno poslvlon and cannccrions.
O MPX, IF and RFulignnem.
Tcs'v; Voltages nl sockets Iar VI, V2, v3, V4, V5 V6 and yasln deluzf r.

o V100, vlol, V102 a. mama (Fumem leakage I. la. namgna les' iuv dlslm'io'h)
o Vollnaas at MPX-decnder tube suckers Vloo, VIOI, V102.