Sharp LC-12A2E, Руководство по обслуживанию

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9
LC-12A2E
[4] Initialization
4-1. Connect the 81 pin and 82 pin of IC2001 (microcomputer) to GND, and turn on the power.
4-2. Select the model name (A2E/A2E(K)).
4-3. Select the inch size (12).
4-4. Return the 81 pin and 82 pin of IC2001 (microcomputer) to the original state.
[5] Transmission data by model
Transmission data
[6] Adjustment
6-1. +B adjustment
1) Receive the E-12CH (PAL color bar).
2) Adjust the voltage of the 49 pin of SC401 to 5.00V
±
0.02V.
Note: Since 5.0V is a reference voltage of all power voltage, adjust it precisely.
6-2. 38.9-VCO adjustment
1) Set the sound system to the B/G mode.
2) Send the CW signal of 38.9MHz, 90dB
µ
V from SG to TP3201 (IF-OUT).
3) Adjust the L3231 coil so that a voltage of 2.5
±
0.2V is obtained at TP3203 (AFT).
Note 1: The input impedance of the digital voltmeter must be 1M
Ω
or more.
Note 2: To adjust L3231, use a non-magnetic driver.
Note 3: No signal must not be input from the antenna.
6-3. 33.9-L’-VCO adjustment
1) Set the sound system to the L’ mode.
2) Send the CW signal of 33.9MHz, 90dB
µ
V from SG to TP3201 (IF-OUT).
3) Adjust the R3233 volume so that a voltage of 2.5
±
0.2V is obtained at TP3203 (AFT).
Note 1: The input impedance of the digital voltmeter must be 1M
Ω
or more.
Note 2: After performing the adjustment of the item 6-2, execute this item.
Note 3: No signal must not be input from the antenna.
6-4. RF-AGC cut-in adjustment
1) Set the sound system to the B/G mode, and receive the E-12CH (PAL color bar).
2) Set the antenna input level to 56dB
µ
V (75
Ω
termination, QP value).
3) Turn the R3231 (AGC volume) clockwise so that the voltage of the TP3202 (RF-AGC terminal) becomes
maximal.
4) Turn it counterclockwise, and adjust the AGC terminal voltage to the point that is lower than the maximal
voltage by 0.5
±
0.2V.
6-5. Opposed bias adjustment
1) Receive the monoscope pattern.
2) Adjust the "COM BIAS" so that the contrast of the stairway-shaped part may become the biggest.
Model E2PROM adress Item Write Data OSD Display