1. T he design of th is pr od uc t con ta in s sp eci al hard ware, many
circuit s and components specially for safety purposes. For
con tinu ed pr ot ection , n o chan g es sh ou ld b e ma de to the o ri g inal
d esi gn un l ess auth oriz ed in writi n g by th e ma nu fact urer.
Replac em en t p arts m ust be ident ic al to thos e u sed in th e or i ginal
ci rcu it s. Serv ice s ho uld b e p er for m ed by qu al if i ed p ers on nel
on ly.
2. Alte r ati on s of the design or ci r cui try of t he prod ucts sh ould not be
made. Any design alterations or additions will void the
manufact ur er 's warrant y and will f urth er r eliev e t he ma nu factu r er
of r esp onsi b ility for per so na l injur y or p r op er ty d am ag e r esult ing
th erefr om.
3. M an y e lectric al and mech ani ca l parts i n th e prod ucts ha ve
special safety-related characteristics. These characteristics are
oft en no t e v ident f r om v isua l i nsp ection n or ca n t he pr o tec t io n
aff or de d by th em nece ssar i l y be ob tain ed b y u sin g r ep l acement
com po ne nts ra ted f or hig he r vol tage, watt ag e, etc. R ep l acem en t
p arts whic h ha ve th ese sp eci al s afet y ch ar ac t er ist ics are
ide ntified i n the parts list of Servic e manua l. El ec tric al
components having such features are identi fied by shading
on t he sche mat ic s an d by (
manual. The us e of a sub s ti tu te rep lacem en t whi ch does n ot
h ave th e same saf ety ch ar act er ist ics as t he r eco mmen de d
replac em ent part sh own i n th e p ar ts lis t of S er vic e man ual may
cause shock, fire, or other hazards .
!!!!
) on the parts list in Service
4. Don't shor t between the LIVE side ground and ISOLATED
(NE UTRAL) side ground or EARTH side ground when
repairing.
Some model's power circuit is partly different in the GND. The
diff er enc e of th e GND i s s ho wn b y th e LIV E : (") side GND , the
ISO LATED(NEUT RAL) : (#) si de GND and EAR T H : ($) side
GND. Don't sh ort b et ween th e LIV E sid e GN D and
ISO LATED(NEUT RAL) side GND or EARTH side GND an d
n ever m ea s ur e w it h a m ea suring a ppa r atus ( osc illos cop e etc.)
th e LI VE si d e GND an d IS OLA TED (NE UTR AL ) s ide G ND or
EARTH side GND at th e s ame time.
If above note will not be kept, a fuse or any parts will be broken.
5. If any repair has been made to the chassis, it is recommended
th at t he B1 set ti ng s hou l d b e ch eck e d or adju ste d ( Se e
ADJUST MENT OF B1 POWE R SUPPL Y) .
6. The hi gh v olta ge app li e d t o th e pictu re tu be mu st confor m with
th at s p ecified in S ervi ce manual. E xcessi ve high volt ag e c a n
cau s e an i ncr e ase i n X- R ay em i ssi on , ar c ing an d possi b le
component damage, therefore operation under excessive high
voltage conditions should be kept to a minimum, or should be
preve nt ed. If s ever e arc ing occ ur s, r emove t he AC pow er
immed i ate ly an d de ter m i ne th e c a use b y visua l insp ec t io n
(inc or rect ins tal lat i on, cracke d or melte d high vo ltage har n ess,
p oor so lder i ng, et c.). To maint ai n the p roper min im u m le vel of
sof t X- R ay emi ssi on, c omp on en ts i n th e hi gh v oltag e cir c uitr y
incl ud ing t he pi ct ur e tu be must be t he e xact r ep l aceme nts or
alte rn at i ves ap pr ove d b y th e ma nuf act urer of th e c om pl et e
product.
7. Do not c hec k high volt age b y dr awing an ar c. Us e a high vol t age
meter or a hi g h v oltag e pr ob e wit h a V TVM. Discharge th e
picture tube before attempting meter connection, by connecting
a cl i p lead to th e gr ou nd f ra me and c onn ectin g th e other end of
the lead through a 10kΩ 2W resi sto r to the anod e b utt on .
8. When se rvice i s require d, ob ser ve th e or i gina l lea d dress. E x tr a
prec aut ion sh ou ld b e g iven t o ass ur e corr ec t l ea d dr ess i n the
high vol tag e c ircui t a r ea. W her e a s hort ci r cuit h as oc cu rre d,
th ose co mp on ent s tha t i ndi ca te evide nce of ove r hea ting sho ul d
b e r e pl ace d. A l wa ys u se th e ma nuf act urer's r ep l acem en t
components.
9. Isolation Check
(1) Dielectric Strength Test
(2) Leakage Current Check
(Safety for Electrical Shock Hazard)
Af ter re- ass emb l in g th e pr odu c t, al w ays per f orm an i sol at ion
ch ec k on the expo sed metal parts of t he c abin et ( a ntenn a
ter m inals, video /audio inpu t and ou tput t erminals , C on trol kn obs,
metal cabi n et, scr ew he ad s, ea r ph one j ack, con trol s haf ts, etc.)
to be s u re th e p roduct is s af e t o ope r ate with ou t dan ger of
elect ri cal s hoc k.
The iso l ati on be tween the AC pr imary ci rcuit an d all metal parts
exp osed t o th e us er , p arti cular l y any e xp os ed met al p art having a
retu rn p ath to t he chass is sho uld withs tan d a vol t age of 3 000 V
AC (r.m. s.) for a period of one second.
(. . . . W it hs tan d a v o lt ag e of 1 10 0V A C (r.m. s.) t o an applianc e
rate d up to 12 0V , an d 3 00 0V AC ( r .m. s.) to an ap pl ian ce r at ed
200V or more, for a period of one second.)
This meth od of test requi res a t est equ ipment n ot g enerally found
in t he servic e trad e.
Plug th e A C line c ord d irect ly into th e AC ou tlet ( d o not use a line
isol ati o n tr ansf or m er du r in g thi s ch eck.). Usi n g a " Lea kage
Curr ent T este r", me asur e th e lea kag e cu rre nt f rom each exp osed
metal p art of the cabinet, p art icu larly any expos ed me tal p ar t
h avi ng a re tur n path to the c h assis , t o a kn own go od ea rt h
ground (water pip e, e tc.) . An y l eaka ge curren t m ust n ot e xceed
0.5mA AC (r.m.s.).
Howev e r, i n tr op ic al area , th is must no t exce ed 0.2 mA AC
(r.m.s.).
""""
Alternate Che ck M et hod
Plug th e A C line c ord d irect ly into th e AC ou tlet ( d o not use a line
isol ati o n tr an s for m er dur ing t hi s che c k.). U se an AC vo lt me ter
h avi ng 1 00 0 ohms pe r volt or mor e s ens itivi ty in th e fo ll owing
manner. Con nec t a 1 50 0Ω 10W res ist or par a lle led by a 0 .1 5µF
AC-type c apa cit or bet ween an expo sed met al pa rt a nd a known
g ood e ar th gro un d (water pipe , etc.). M eas ure th e A C volt ag e
acr oss th e res ist or w ith th e AC vo ltm eter . Move th e r esis tor
con nec ti on to each exp ose d metal part, part ic ularly a ny exp os ed
metal p art havin g a retu rn pat h to t he ch as sis , an d m easu re th e
AC vol tag e ac ro ss the res ist or . No w, re vers e th e pl u g i n th e AC
ou tl et and re pe at eac h mea s ur emen t. Any volt ag e me asured
must no t e xceed 0 .75V AC (r.m. s.). This c orre spo nds to 0.5mA
AC (r.m. s.).
Howeve r, in tropica l are a, this must n ot exceed 0.3V AC ( r.m.s.).
This corresponds to 0.2mA AC (r.m.s.).
AC VOLT MET ER
(HAVING 1000 Ω /V,
OR MOR E SENSIT IVITY)
0.15μF AC-T YPE
PLACE THIS PROBE
1500 Ω 10W
GOOD EARTH GROUND
ON E A C H EX PO SE D
ME T AL PA RT
4
No.51944
A
A
FEATURES
V28CH1EUS
V28CH1EUB
"
New c hass is d es ign ena bl e us e of an i nte rac ti ve on screen
control.
"
The TELETEXT SYSTEM has a built-in FASTEXT (UK syst em),
TOP (Germ an syst em) and W ST (world standard system)
system.
"
Be c aus e th is T V un i t cor r esp on ds t o m ultiple x br oa dc a st, u s ers
can enjoy music programs and sporting events with live realism.
In ad di ti on , BI LIN GUAL programs can b e h ear d in th eir or i g in al
language.
TVEXT-1EXT-3
EXT-2
"
Users can make VCR dubbing of picture and sound by controlling
th e AV s elec tor to se lec t an optiona l so urc e at th e EXT- 2 outp ut
sh own i n fi gu re.
EXT-4
MAIN DIFFERENCE LIST
Model Name
!
Par t Name
!
FRONT CABINE T ASSYLC 10001- 008C- ULC 1000 1-00 9B-U