LG 21FS2CG Service Manual page 15

12. Inspection Item
12-1. Multiplex Sound Adjustment
1) Received 06CH factory signal. Check if the OSD displays
"ST." for Stereo Broadcasting.
2) Press sound multiplex(MPX) button for stereo sound
separation. Check if the "L" channel produce 1kHz output.
3) Received 02CH factory signal. Check if the OSD displays
"SAP" for Secondary Audio Program Broadcasting.
12-2. External Input(A/V IN)
1) Connect through 75 ohm A/V input terminal standard
picture signal. The standard video input level is 1Vp-p.
2) Connect to input terminal sound signal strength of 1kHz
400mVrms(1.13Vp-p) and compare status.
3) Check picture status by if it is in good condition by
pressing the TV/AV IN key on the remote control and
compare standard input condition of the receiver.
4) Check speaker output status if it is in good condition and
check input terminal against receiver ground by
connecting "R" channel of RCA JACK.
12-3. Signal, Sound Adjustment Condition
(1) Necessary parts and instrument
- Adjustment remote control(with signal, sound check button)
* LG standard, DATA CODE FC(h) FD(h)
(2) Checking
1) Received US30CH standard signal.
2) Check CONTRAST, BRIGHTNESS, COLOR, TINT,
SHARPNESS by pressing the Signal Check button
continuously.
3) Received US06CH.
4) Check STEREO function by pressing Sound Check button.
13. TV/CABLE TV Channel operation
condition
(1) Necessary parts and instruments
- Remote controller (with AIR/CABLE TV button)
(2) Checking
- Check receiver channel operation for some abnormality by
pressing AIR/CABLE TV button continuously.
13-1. HOLD DOWN CHECK (X-RAY Protect)
- This X-RAY Protect testing is applicable only for model with
HOLD DOWN circuit only.
(1) Checking
1) Check HOLD DOWN circuit operation by shorting R419.
2) At this time, the receiver turns to POWER OFF and goes
to STAND-BY condition. Accordingly, the high voltage
does not occurred and you can perform HOLD DOWN
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