Acer H15AAX Service Manual page 6

8. E 2 PROM (Circuit diagram MAIN PWB)
Dat a t rans f er b et w een I3 0 4 an d C P U (C i rcu i t d i ag ram M AIN P W B page 4 / 7 (I3 03) i s effect ed t hro u g h t he IIC
bu s S C L (pi n 9 ) an d SDA (pi n 8) of I3 00 o r S C L (pi n 4 2 ) an d SDA pi n 3 9 of I30 1 . The d at a t o b e t rans ferred t o
each d evi ce are s t o red i n I3 04 .
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I300 co nt rol dat a.
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OS D rel at ed s et t i ng d at a.
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Ot her cont ro l dat a fo r s erv i ce m en u.
9. CPU circuit (Circuit diagram MAIN PWB)
I3 0 3 ( M TV 31 2M 64 ) (S M 8 95 16 C 2 5) o r ( W78 E 62 B P -40 ) f unct i on s as t h e C P U.
The s ou rce vo l t ag e fo r t h e d evi ce i s 5 . 0 V an d t h e s y s t em cl oc k freq u ency i s 12M Hz.
9 . 1 Det ect i o n of P OWER s wi t c h s t a t u s
The C P U i den t i fi es t h e ON s t at u s of t h e t wo p ower s u p p l i es . Th e i d e nt i fi cat i on i s m ad e when t h e p o wer s up p l y
i s t urned off. F or ex am p l e, i f t he p ower s up p l y is t u rn ed off wi t h t he P OWER s wi tch, t he P OWER s wi t ch mus t be
t urne d on when act i vat i n g t h e po wer s u pp l y a g ai n . If t he p o wer s up p l y i s t urn ed off by p u l l i n g out t he p o wer
cor d , t hen t hi s p ow er s u pp l y can b e t u rn ed on b y conn ect i n g t h e p o wer cord , wi t h o u t pre s s i n g t h e P O WER
s w i t ch .
9 . 2 Di s pl ay m od e i de nt i f i cat i o n
9. 2. 1 F un ct i o n s
(1) Di s pl a y m od e i den t i fi cat i o n
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The di s pl ay m ode of i np u t s i g n al i s i d enti fi ed b as ed o n Tabl e 1, and accord i ng t o t h e frequen cy an d pol ari t y
(HP OL, VP OL) of h ori zo nt al or vert i cal s y nc s i g n al , pres en ce of t he h ori zont al o r vert i cal s ync s i gn al , and t he
di s c ri m i na t i o n s i g n a l (H S YN C _ DE TE C T , VS YN C _ DE TE C T ).
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When t he m od e h as been i den t i fi ed t hrou gh t h e m eas u rem ent of h ori zont al an d vert i cal freq u enci es , t he t ot al
num ber of l i nes i s d et erm i n ed wi t h a form u l a o f " Hori zo n t al f req uency / Vert i c al frequ ency = To t al n u m b er
of l i nes . "F i n al i d ent i fi c at i on can be m ade b y exa m i ni n g t h e coi nci d ence o f t h e ob t ai ne d fi g ure wi t h t he
num be r of l i nes for t he m o d e i den t i fi ed fro m t he freq u en cy.
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When t he d et ect ed frequen cy i f t h e s yn c s i gn al h as ch anged , t h e t o t al num ber of l i nes s h o u l d be count ed ev en
t h ro ugh i t i s rge i d ent i fi e d frequ ency i n t h e s am e m ode. Then, i t i s n eces s ary t o ex am i ne whet her t he p res et
val ue fo r t h e v ert i cal d i s p l a y po s i t i on o f It em 4- 3 h as excee ded t h e t o t al n u m b er of l i nes . If ex c eeded , a
m ax i m um v al ue s h ou l d be s et u p, wh i ch
(2 ) O ut -o f - ran g e
Thi s out -o f-rang e m od e i s as s u m ed wh en t he fre q uen cy of t he h o ri z o n t al / v ert i cal s i g n al i s as s peci f i ed bel ow.
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Vert i cal frequ en cy : B e l o w 5 0Hz or ab ov e 85 Hz
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Hori zont al fr equ ency : B el o w 2 4 KHz o r abo v e 75 KHz
(3) P ow er s a v e m o d e
The power s av e m o de i s as s u m ed
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If t here i s no h ori zo nt al s y n c s i g nal in p ut .
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If there i s no v ert i cal s y n c s ig nal i np ut .
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If t he hori zo nt al s yn c s i gn al i s ou t s i de t he m eas u ri n g ran ge o f I3 0 0 .
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If t he vert i cal s yn c s i g nal i s o ut s i d e t h e m eas u ri n g ran ge o f I3 0 0 .
Ci rc ui t De scri pt i o n
d oes not e xceed t h e vert i cal d i s pl ay pos i t i on of It em 4 -3.
wh en t he h ori zo nt al / v ert i cal s i g n al s are as s peci f i ed bel o w.
H15AAX (AL502)
Pag e 3