Read Sharp LC-22AD1E (serv.man7) Service Manual online
23
LC-22AD1E
4. Adjustment
(1) +B adjustment (R3717)
a) Receive the standard colour bar signal.
b) Connect a digital voltage meter to TP3722.
b) Connect a digital voltage meter to TP3722.
Adjust the voltage to 5.00V
±
0.02V using R3717 (trimming VR). Specified value: 5.00V
±
0.02V
Note:
Since the reference voltage for all of the supply voltages is 5V, make sure you set the 5.00V
adjustment accurately.
adjustment accurately.
(2) +B adjustment (R4525)
a) Receive the standard colour bar signal.
b) Connect a digital voltage meter to TP4531.
b) Connect a digital voltage meter to TP4531.
Adjust the voltage to 13.00V
±
0.05V using R4525 (trimming VR). Specified value: 13.00V
±
0.05V
Note:
Since this is the reference voltage for the power supply for gradation, make sure you set this
adjustment accurately.
adjustment accurately.
(3) Counter-bias adjustment
•
This adjustment minimizes the flicker on the screen.
•
To set the COM BIAS shown on the first page of the adjustment
process, perform this adjustment at 50 Hz and 60 Hz,
respectively.
process, perform this adjustment at 50 Hz and 60 Hz,
respectively.
a) Refer to the previous item [2] to enter the [adjustment process
mode].
The first page of the adjustment process, shown in the drawing
on the right (Fig. 3-1), will be brought up.
The first page of the adjustment process, shown in the drawing
on the right (Fig. 3-1), will be brought up.
b) Select [G/A] on the second page of the adjustment process
using the cursor “(
"
)” key, and press the “OK” key (Fig. 3-2).
(The second layer item appears.)
• Next, press the cursor ”(
• Next, press the cursor ”(
"
)” key twice, to bring up the display
shown in Fig. 3-3, on the third page of the second layer.
• Select [G/A TEST PATTERN 1], on the third page.(In this
case, the set value should be [0].)
• Press the cursor “(
û
)” key repeatedly to set the set value
to [14].(In this case, [14] is [dot reverse flicker pattern 2].)
• Press the “RETURN” key and the cursor “(
'
)” key to return
to the first page of the adjustment process.
c) Select the first page, [COM BIAS 50], using the cursor
“(
'
)/(
"
)” keys.
d) Press the cursor “(
Û
)/(
û
)” keys repeatedly. Stop pressing
it when the flicker on the screen is at the lowest level possible.
(In this example, the value set for set COM BIAS 50 is [105].)
(In this example, the value set for set COM BIAS 50 is [105].)
e) Next, select the first page, [COM BIAS 60], using the cursor
“(
'
)/(
"
)” keys.
Press the cursor “(
Û
)/(
û
)” keys repeatedly. Stop pressing
it when the flicker on the screen is at the lowest level possible.
(In this example, the value set for set COM BIAS 60 is [108].)
WLD 26 VER 1.000 DTV VER
INCH
SIZE
22
MODEL
AD1E
ERROR NO RESET
0
1BIT_AMP ERR
0
PUBLIC MODE
OFF
COM BIAS 60
100
COM BIAS 50
100
PAL TAMP
20
SECAM TAMP
20
AV AMP
20
TAMP L
160
Y
READ VALUE
TAMP M
168
Fig. 3-1
First page of the first layer of the adjustment process
WLD 26 VER 1.000 DTV VER
12C DATA
000000000000
12C DATA
WAIT
MSP
VPC
G/A
TUNER
FLI12310
DSP
DOLBY
DELAY
TEXT
OTHERS
VPC
G/A
TUNER
FLI12310
DSP
DOLBY
DELAY
TEXT
OTHERS
Fig. 3-2
Second page of the first layer of the adjustment process
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