Sharp 21SFX10L Service Manual - Page 15

21S-FX10L ADJUSTMENT PRECAUTION : Make sure TV Set is in "NORMAL CONDITION" before switch to Service Mode for Adjustment. PIF ADJUSTMENT CHECKING NO ADJUSTMENT POINT ADJUSTMENT CONDITION/PROCEDURE 1 RF-AGC (1) Receive the "US 10 CH HALF Color Bar" signal. TAKE OVER POINT Signal Strength: 56 ± 1dBμV (75 ohm open) ADJUSTMENT (2) Connect the oscilloscope to JA402 (Tuner's AGC Terminal) as shown in (I2C BUS CONTROL) figure 3-1. + OSCILLOSCOPE (AUTO & MANUAL ADJ) JA402 0.1V - + BIAS BOX TV SET - Bias Box : about 4.5V Fig. 3-1 (3) Call V09 in service mode. Adjust the V09 bus data to obtain the Tuner output pin drop 0.1V below maximum voltage. (4) Change the antenna input signal to 63 ~ 67dBμV, and make sure there is no noise. (5)Turn up the input signal to 90 ~ 95 dBμV to be sure that there is no cross modulation beat. WAVEFORM OR OTHERS * for Auto ADJ 1)Receive "NTSC COLOUR BAR" signal signal strength : 56 ± 1 dBμV (75 ohm open). 1) Go to service mode. 2) Go to service data V09 , press R/C to operate "Auto-AGC" key and confirm the OK display on the screen 3) If appear red display with NG sign, increase data some step and please repeat step 2. 4) Proceed step 4 & 5 in manual mode. FOCUS ADJUSTMENT NO ADJUSTMENT POINT ADJUSTMENT CONDITION / PROCEDURE 1 FOCUS (1) Receive US4 CH LION HEAD Signal (NTSC 60 Hz). (2) Press RESET to set Picture NORMAL condition. (3) Adjust the focus control to get the best focusing. WAVEFORM OR REMARKS Focusing Point (middle of center and edge of monoscope pattern) H-VCO, VIF-VCO & S-TRAP fo ADJUSTMENT NO ADJUSTMENT POINT 1 H-VCO ADJ (I2C BUS CONTROL) (AUTO & MANUAL ADJ) ADJUSTMENT CONDITION / PROCEDURE (Manual Adj) (1) In No signal (RASTER) condition. (2) Go to service mode, choose service data V25. (3) Connect oscilloscope to IC801 pin13 (H-OUT), adj V25 until freq become 15.735 ± 0.2KHz. (Auto Adj) (1) In No signal (RASTER) condition. (2) Go to service mode. (3) Choose service data V25, by pressing R/C "AUTO H-VCO" key, OSD will appear "OK" at screen. (4) If appear "NG" pls repeat step 3. 2 VIF-VCO ADJ (I2C BUS CONTROL) (AUTO & MANUAL ADJ) (Manual Adj) (1) In No signal (RASTER) condition. (2) Go to service mode, choose service data V14 (3) Connect oscilloscope to IC801 pin7 (AFT), adj V14 until voltage become 2.5 ± 0.5 V DC (Checking spec : 2.50 ± 1.5 V) (Auto Adj) (1) In No signal (RASTER) condition. (2) Go to service mode, choose service data V14. (3) Press the R/C "AUTO PIF-VCO" key, OSD will appear "OK" at screen. (4) If appear "NG" pls repeat step 3. 3 S-TRAP fo ADJ (I2C BUS CONTROL) (AUTO & MANUAL ADJ) (Manual ADJ) (1) In No signal (RASTER) condition. (2) Go to service mode, choose service data V26. (3) Connect oscilloscope to TP 801 or IC801 pin 30, adj V26 until voltage become Min (below 5 V). (Auto Adj) (1) In No signal (RASTER) condition. (2) Go to service mode, choose service data V26. (3) Press the R/C "AUTO S-TRAP" key, OSD will appear "OK" at screen. (4) If appear "NG" pls repeat step 3. WAVEFORM OR OTHERS *NOTE: This adjustment must be done after aging at least 3 minutes. 5 - 3