PRS-300
9
SECTION 4
ELECTRICAL ADJUSTMENT
VCOM VOLTAGE ADJUSTMENT
Vcom voltage for the display panel varies for each panel. VCOM
adjustment is required when replacing a board or panel.
Preparation:
Voltage is generated only when the screen is changed, so the
adjustment needs to be performed while changing the screen. Use
the slideshow function to change the screen sequentially.
1. With the “Settings” tab in the menu selected, press the
[ENTER] button or the [0] button.
2. With the “Slideshow” tab selected, press the [ENTER] button
or the [3] button.
3. Set “Turn On, Slide Duration 05 seconds”, and press the
[ENTER] button on OK.
Procedure:
1. With the “Pictures” tab in the menu selected, press the
[ENTER] button or the [9] button.
2. Specify a desired screen, and press the [ENTER] button to
check that the slideshow starts.
3. Observe the TP354 on an oscilloscope (refer to Fig.2), and use
RV1801 to adjust the voltage that is generated when the screen
is changed so that it satis
fi
es the standard.
Standard: Written on the
fl
exible card wire of the display panel with
a marker. (–1 V to –2.5 V) (Refer to following Fig.1)
(In case of Fig.1: The value of VCOM is –1.75 V.)
Fig. 1
Fig. 2
Adjustment Location:
RV1801
IC301
TP354
– MAIN Board (Component Side) –
500 mV/DIV, 200 ms/DIV
1 Vp-p
660 ms
