ViewSonic ViewPanel VP140 Service Manual page 71

ViewSonic Corporation
INTRODUCTION
1 The Liquie Crystal Display (CD) monster falis under one of tne innovative
mainterarce service of the product p a r i l y 728s new 'epairing techniques
Since our user service system should be offered 28 quickly as possible, itis necessary te provice new tecrnclog cal
intormation concerning the product
Vors concretely, ths rew technology reiates to that fo corer rom analog to cigtal systems To cur reg)
itis rather aiffcut to supply all the service intcrmation at ins stage of development
2 Unce: these circumstances, the service orccedures ate civided inte the two steps, STE-1 anc STEP-2, by makrg
Use cf she cnaracter sts of he LCD monitor, as described below.
+ Step 1: To reoiace Main PCB.
+ Step 2: To repair the Main PCB interior.
relogical commodity felas. ard ne
however
[ Characteristics of servicing of LED moniters
+ An LCD monitor can be divided 'oughly into an LCD panel unit and a main PCB,
' + The LCD panel uses digital signals :o show pictures on a screen. The main PCB converts analog signals
produced from a computer into digital ones and reproduces them on the LCD panel. This means an adition
of digita signals to the LCD panel allows a picture to be shown on the screen.
+ 11 the digital signals which are produced from the main PCB are normal, the LCD panel will show a normal |
picture
Since 1 gital signals are transmited and received between the LCD panel and the main PCB without needing
'any particular connecting techniques. ne particular adjustment will be needed even if ether the LCD panel or
|___the main PCB is replaced with anew one,
3 Cencrete description of STE?-1 and STE®-2 of the custome' service
Classification [Tem T STEPA STEP-2
"Assistance to servicing| Service manual | To be issued To be issued
{ in June 1997 in August 1997
'Adjusting procedures ("1) | Data setting only 'Adjustment partly needed
Servicing techrical data a Tobe publisnec upon
preparation (August 1997)
Scope of parts fain POB Fplacing a unt Repair
replacement ('2) | Fluorescent lamp Replacing aunt [Replacing aunt
Inverter PCB Replacing a unit Replacing a unit
AG adapter Replacing a unit Replacing a unit
"Adjustment ater replacing a cart
Ne particular adjustment is needed e v e n alte' any of the aoove-menticnec tive unis is "eplacea wih a new
ewever, data selting alone is needed ifa vain 2CB is replaced
'On the other hend, adjustment is neecee in cart (brghiness, sub-cort., 1.0 level adj) f analcg veut parte are
replaced at the widec inaut stage ¢! :ne ora PCB inter oF,
*2 The scape of parts replacement
Tre folowing kinds of repair par's wil be supplied 1 a following comigestion
1) Main PCB
Tris is a PCB to carvert aralog signais coming 'tom a computer inio digita' cnes wrich an LCD 2anel uritrneeds.
Atrough all the compovents in the ©C8 shculd oreterably ne repaired, we shall cope wth "ecuests for renair ay
he beginning of the serving, because new renairing techniques a r e re2ded 'replacing a uni for the time being
(9 regait al tne comipenents,
2) .CD panel unit
This unt receives d gral signa's "om the main PCB anc asplays pictures on tre screen. Ths unttis composed of
an LOG panel, a pansl-deiving PCB, ang tluorescert lamps. Neither tre LCD pane! nor the pave-crivng PCB are
repaired cr cusp ied incenencently
VP140
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