Philips DELLP1230, Руководство по обслуживанию

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Dell P1230 M25P Circuit Description
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1.
G
ENERAL
D
ES
C
RIPTION
Th e P1230 using 22 fl at A G C RT is rea l Digita l Contro ll e d A uto -
scan Co l or Disp l a y M onitor w it h h ig h reso l ution wh ic h can operate
h ori z onta l scan f re q uenc y f ro m 30KHz up to 130KHz, an d vertica l
scan
f
re
q
uenc
y f
ro
m 50
to
160 Hz.
P1230 is e q uippe d w it h an e mb e dd e d m icro - contro ll er to provi d e
re
q
uire
d
preset
m
o
d
es an
d w
e
ll
a
dj
uste
d by f
actor
y
t
h
en store
d
t
h
e
d
ata into
EEPROM,
it a
l
so provi
d
es
m
an
y f
unctions
,
suc
h
as
d
igita
lly
a dj usta bl e picture , po w er m anage m ent , s R G B, l o w e m ission , h ig h
i mm unit y, DDC 2B ---- etc .
This monitor complies with TCO99/TCO03 low emission
standard, E2000 automatic power saving requirements, to
reduce power consumption less than 2 watts in power saving
mode, also fulfill VESA standard and energy star computer
program of the EPA.
2.
D
ES
C
RIPTION OF
C
IR
C
UIT
D
IA
G
RAM
Th
is
d
escription
b
rie
fly
intro
d
uces t
h
e
f
unctions inc
l
u
d
ing po
w
er
supp ly, po w er saving m anage m ent , h ori z onta l / vertica l d e fl ection ,
vi d eo a m p l i f ier , m icro - contro ll er an d purit y an d convergence contro l,
etc
.
A. POWER SUPPLY / POWER SAVIN
G
MANA
G
EMENT
Th e m onitor is d esigne d to a d opt s w itc h ing m o d e po w er supp ly
wh
ic
h
can operate
m
ains input
f
ro
m 90VA
C to
264VA
C
,
t
h
is
s
w
itc
h
ing po
w
er supp
ly
app
l
ies an
I
C
(STR-F6656
or
STR-F6456)
f or QUASI-RESONANT MO D E contro ll er , t h at po w er MOSFET is
pac k e d insi d e as w e ll. Th e contro l sc h e m e trans f or m s a s w itc h ing
converter
f
ro
m
a vo
l
tage source into a
m
u
l
ti
-
output vo
l
tage
,
t
h
e
contro
l
concept is e
xh
i
b
ite
d m
an
y d
esira
bl
e properties suc
h
as
in h erent over -l oa d protection , sta bl e an d f ast s y ste m response , t h e
m a x i m u m po w er d e l iver y is up to 180 w atts , t h en to b e l i m ite d by
l
i
m
iting circuit
f
or sa
f
et
y
reason
,
secon
d
ar
y f
ee
db
ac
k
via a p
h
oto
-
coup l er is use d to o b tain a sta bl e output vo l tage , t h e m u l ti - outputs
supp ly a ll necessar y vo l tages to d e fl ection , vi d eo an d rest e x cept
m icro - contro ll er .
I n or d er to m eet ne w re q uire m ent o f E2000 - po w er consu m ption
l ess 2 w atts @ o ff m o d e , an e x tra secon d po w er supp ly is a d opte d,
t
h
is
2
n
d po
w
er app
l
ies
SOPS
tec
h
no
l
og
y,
not on
ly
supp
ly
t
h
e
+5V
to
m
icro
-
contro
ll
er
,
it is a
l
so use
d
to start up t
h
e
m
ain po
w
er supp
ly
m
entione
d
a
b
ove
,
suc
h d
esign concept can re
d
uce po
w
er
d issipation in po w er start up circuit , in or d er to d e l iver enoug h
po w er in nor m a l ON operation , t h e 2
n d
po w er m ust w or k at h ig h
f
re
q
uenc
y m
o
d
e
,
an
d
to
b
e s
w
itc
h
e
d
into
b
urst
m
o
d
e via
m
icro
-
contro ll er f or l ess 2 w atts re q uire m ent @ o ff m o d e , t h is d esign h as
b een consi d ere d an d e x ecute d at l o w an d h ig h m ains vo l tage .
All
recti
f
ie
d d
io
d
es on secon
d
ar
y
site are
w
it
h
out
l
ea
d f
ra
m
e
(h
eat
-
sin k), it gains so m e cost saving in t h er m a l d esign , b ut t h e turn
ratios o f m ain trans f or m er s h ou ld b e f i x e d to m aintain an a d e q uate
vo
l
tage
d
erating o
f
pri
m
ar
y
s
w
itc
h
ing
MOSFET
an
d
secon
d
ar
y
+230V recti f ie d d io d e 31 D F6 (w it h b etter t h er m a l per f or m ance ),
t h is is tra d e o ff d esign in b et w een , t h e ot h er h an d, a pri m ar y DC
po
w
er s
w
itc
h wh
ic
h
can rep
l
ace
A
C po
w
er s
w
itc
h
is a
l
so reserve
d
b
ut s
ymb
o
l
on t
h
e
b
e
z
e
l m
ust
b
e
m
o
d
i
f
ie
d f
or t
h
e appro
b
ation
reason
.
Th is m onitor w i ll enter po w er saving OFF m o d e wh i l e no s y nc
signa l input an d auto m atica lly recover to nor m a l po w er ON wh en
s
y
nc signa
l
s are
d
etecte
d by m
icro
-
contro
ll
er
.
During Off m o d e operation , a ll t h e output vo l tages o f m ain po w er
are re
d
uce
d
to
z
ero
,
on
ly
t
h
e re
q
uire
d
vo
l
tage o
f m
icro
-
contro
ll
er is
supp
l
ie
d by
secon
d
po
w
er supp
ly,
it is a
l
so use
d
to restart t
h
e
m ain po w er wh i l e m onitor w a k e - up f ro m OFF to ON
A. HORIZONTAL D EFLE C TION / VERTI C AL D EFLE C TION / EHT
G
ENERATOR
HORIZONTAL DEFLECTION
:
Th
e
h
eart o
f h
ori
z
onta
l/
vertica
l d
e
fl
ection is
T
D
A4856 -- d
e
fl
ection
contro
ll
er
, wh
ic
h
can o
ff
er a co
m
p
l
ete an
d
e
ff
icient s
m
a
ll
signa
l
s
y
nc
processing f or auto - s y nc m onitors , a ll f unctions are contro ll e d via I2 C
b us .Th is contro ll er T D A4856 h an dl es s y nc processing to accept
separate an
d
co
m
posite
(H+V)
input signa
l
s
,
it a
l
so provi
d
es e
x
tensive
f
unctions
l
i
k
e a
fl
e
x
i
bl
e
B+
contro
ll
er
bl
oc
k
o
f H-d
e
fl
ection an
d
a
geo m etr y contro l w it h f aci l ities , l ea d ing to e x ce ll ent picture q ua l it y, t h is
d evice a l so can d irect ly d rive t h e vertica l d e fl ection output stage , l ine
d
river stage
, E/W
output stage an
d
a
ll
contro
l
s are trac
k
e
d w
it
h
t
h
e
inco
m
ing
f
re
q
uencies
,
picture can
b
e a
dj
uste
d
a
l
ong
h
ori
z
onta
l d
irection
by H- s h i f t contro l. Th e h ori z onta l si z e , east /w est , trape z oi d corrections
are o b taine d by var y ing t h e supp ly vo l tage o f H-d e fl ection circuit via
b
uc
k
converter
,
seven capacitors p
l
us po
w
er
MOSFET
s
w
itc
h
es an
d
DC contro ll e d l inearit y coi l are d esigne d f or opti m a l screen h ori z onta l
l inearit y.
VERTICAL DEFLECTION:
Th e m a j orit y o f vertica l d e fl ection f unction is integrate d by t w o I Cs :
T D A4856 an d STV9379.
Th
e
T
D
A4856
ta
k
es care o
f
s
y
nc po
l
arit
y
correction
,
auto
m
atic catc
h
ing
an d h o ld ing o f t h e vertica l osci ll ator , to generate sa w- toot h d rive current
f or vertica l output , C an d S correction , t h e ot h er h an d, it a l so generates
a correct
V-bl
an
k
ing pu
l
se
f
or vi
d
eo
bl
an
k
ing
d
uring vertica
l
retrace
interva l.
Th
e
STV9379 --
a DC
-
coup
l
e
d
vertica
l d
e
fl
ection
b
ooster an
d d
riving
by
d
i
ff
erentia
l
input is suita
bl
e
f
or C
RT
co
l
or
m
onitor
,
t
h
e output stage
w
it
h
t h er m a l, soar protection , an d h ig h l inear sa w- toot h signa l a m p l i f ication
to o b tain t h e re q uire d an d re l ia bl e vertica l d e fl ection current .
EHT
G
ENERATOR
Th e I C L5991A is use d as EHT contro ll er to generate re q uire d e x tra
h
ig
h
vo
l
tage
f
or C
RT
ano
d
e
,
t
h
e
l
ine output trans
f
or
m
er
(LOT)
trans
f
ers t
h
e vo
l
tage to re
q
uire
d
ano
d
e
vo l tage an d rest tertiar y output vo l tage . Th e a dj usta bl e f ocus G 3, G 4
an d screen G 2 vo l tages are interna lly d erive d f ro m t h e ano d e vo l tage ,
ot
h
er secon
d
ar
y w
in
d
ings are use
d
to generate re
q
uire
d
vo
l
tages
f
or G
1
an
d
spot
k
i
ll
er use
d, F
or sa
f
et
y
reasons
, x-
ra
y
protection circuit is
inc l u d e d in L5991A wh ic h w i ll s h ut d o w n EHT generator i f t h e ano d e
vo l tage e x cee d s a certain va l ue (29kV), t h e ot h er h an d, over b ea m
current protection is a
l
so avai
l
a
bl
e
by
co
mb
ination o
f
t
w
o s
m
a
ll
transistors an d severa l resistors , d io d e an d capacitor , it w i ll sense t h e
b ea m current f ro m ABL circuit an d activate t h e so f t start o f L5991A to
d
ecrease
EHT
in case t
h
e tota
l b
ea
m
current e
x
cee
d
s speci
f
ie
d
va
l
ue
.
B. VI
D
EO AMPLIFIER &
DDC
2B
VIDEO AMPLIFIER:
Th e vi d eo circuit m ain ly consists o f pre - a m p l i f ier T D A4887, LM2412,
post a m p l i f ier an d DC restoration circuit , t h e vi d eo DC l eve l an d gain at
cat
h
o
d
e is contro
ll
e
d
via
I2
C
b
us
&
so
f
t
w
are
.
Th
e re
d,
green an
d bl
ue vi
d
eo signa
l
s are a
m
p
l
i
f
ie
d by
pre
-
a
m
p
l
i
f
ier
an d post - a m p l i f ier , t h en A C coup l e to ne x t stage - DC restoration
circuits , t h ere are t h ree cut - o ff a dj ust m ents are provi d e d in t h is stage to
set necessar
y
vi
d
eo
bl
ac
k l
eve
l
at cat
h
o
d
e
f
or a
ll
t
h
ree guns
. I
n a
dd
ition
cut - o ff, t h ree in d ivi d ua l gain a dj ust m ents at pre - a m p l i f ier are use d to
a dj ust re q uire d co l or point (wh ite b a l ance ), b ot h cut - o ff an d gain contro l
are
d
igita
l
contro
l
via
I2
C
b
us
.
A
spot
-k
i
ll
er circuit is
b
ui
l
t in to prevent t
h
e C
RT d
a
m
age
d
ue to spot
b
urn out
wh
en t
h
e set is s
w
itc
h
e
d
o
ff.
DDC 2B:
V
ia e
x
terna
l
DDC
_S
C
L,
DDC
_S
D
A
an
d
interna
l S
D
A
an
d S
C
L,
t
h
e
in f or m ation a b out t h e m onitor , inc l u d ing t h e seria l nu mb er , pro d uction
Co d es , C RT t y pe an d app l ica bl e ti m ings , - - - - are store d in t h e
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