Service Adjustments - Fisher PC-R20R2 Service Manual

Service Adjustments

Please notice the following before alignment and equipment
1. Don't short any two soldering points, which should not be shorted and don't touch any components,
which should not be touched.
2. Please pull out plug before equipment.
3. For safety reasons, all components equipped or replaced should be identical with BOM.
4. Must be warm up for 30 minutes or more and degauss CRT thoroughly with demagnetizer before
alignment.
The data of EEPROM must be stored before the adjustment for main chassis. And EEPROM must be
corrected by the correct file "3Y03_ROM_CORRECT.hex" to avoid signal of CH6 weaken. R.bias,
G.bias, B.bias, R.drv, G.drv, B.drv should be set to proper values. Sub_bright is set to 63 usually.
Tools and equipments for adjustment
1. small "-" screwdriver
2. screwdriver without inductance
3. Pattern Generator
4. DC Regulated power supply
5. Digital Voltmeter
6. Sweep Signal Generator
7. 20MHz 2-channel Oscilloscope
Signal condition
ITEMS
1
2
3
4
Adjust for main chassis
PIF Adjustment (45.75MHz)
a.
Tuner AGC connects to GND. Pattern Generator outputs 45.75MHz I.F. signal (70dbµV)and connects to SAW filter
output terminal through a capacitor .
b. Connect Digital voltmeter across C227. DC Regulated power supply positive terminal output +14V to C617.
c. Adjust L203 coil to obtain 3.6V Digital voltage meter reading.
NOTE:
To cancel this adjustment , L203 can be adjusted before inserted to the chassis with a special equipment
PICTURE
LOGO
CARRIER
CH14 471.25 MHZ
CH3 61.25 MHz
CH8 181.25 MHz MONOSCOPE
CH12 205.25 MHz
-10-
PATTERN SYSTEM
COLOR BAR NTSC/M
GRAY SCALE NTSC/M
NTSC/M
NTSC/M
CROSS HATCH
SOUND
REMARK
MODE
MONO
1KHz
BTSC
0.3k,3kHz
MONO
MUSIC
MONO
1KHz
.