SHARP 21VR2 Repair Manual

21VR2
PROTECTOR PERFORMANCE CHECKFUNCTION CHECK (VIDEO AND AUDIO)
No. Adjusting pointAdjusting procedure/conditionsWaveform and othersNo. Adjusting pointAdjusting procedure/conditionsWaveform and others
1Beam protec-1. Receive the E-5CH (monoscope pattern) signal.* Short-circuit any of the Q851,1CONTRAST1. Receive the E-5CH signal.
tor2. Set the contrast control to maximum.Q852 and Q853.key2. Select the contrast on the P-MODE screen.
3. Set the brightness control to maximum.3. The contrast must be changeable with the UP/
4. Make a short-circuit between the collector andDOWN key.
emitter of Q851, Q852 or Q853 and make sure
that the protector is activated and the stand-by2COLOUR key1. Receive the E-12CH signal.
mode is called.2. Select the colour on the P-MODE screen.
3. The colour must be changeable with the UP/
2High-voltage1. Receive the E-5CH (monoscope pattern) signal.DOWN key.
protector2. Connect the bias box to the cathode (R635 side)
of D607.3BRIGHTNESS1. Receive the E-5CH signal.
3. Adjust the bias box voltage to 18 V and makekey2. Select the brightness on the P-MODE screen.
sure that the protector is not activated.3. The black level must be changeable with the UP/
4. Adjust the bias box voltage to 27 V and makeDOWN key.
sure that the protector is not activated.
4TINT key1. Receive the NTSC colour bar signal. (A/V)
3Other protec-1. In checking the performance of other protectors2. Select the tint on the P-MODE screen.
torsN for example, the one against shorting of3. The tint must be changeable toward green with
smoothing electrolytic capacitor of +B line N, paythe UP key and toward red with the DOWN key.
attention not to damage or deteriorate any related
element.
5PIC-NOR. key 1. Press the NOR. key on the P-MODE screen to* The contrast, colour, brightness,
make sure all the displayed items are at normaltint and sharpness settings are
settings.all normal when these items do
10not appear on the screen.
See below for the normal settings.
E Contrast: MAX
E Colour: CENTER
E Brightness : CENTER
E Tint: CENTER
E Sharpness : CENTER
A/V INPUT AND OUTPUT CHECK
No. Adjusting pointAdjusting procedure/conditionsWaveform and others
1Video and1. Receive the E-12CH colour bar (100% white col-6SHARPNESS1. Receive the E-5CH signal.
audio outputour bar, 400 Hz, 100% modulation audio) signal.key2. Select the sharpness on the P-MODE screen.
check2. Terminate the video output with a 75 ohm imped-3. The sharpness must be changeable with the UP/
ance. Make sure the output is as specifiedDOWN key.
(1.0 Vp-p ?3 dB).
3. Terminate the audio output with a 10k ohm im-
pedance. Make sure the output is as specified7Channel sign1. The display colour of all the channel (0-99) signs
(1.76 Vp-p ?3 dB).display colourmust be green. Keep the AFT on.
2Video and1. Using the TV/AV key on the remote controller,
audio inputmake sure that the modes change in the order of
checkTV, AV1, AV2 and TV again and that the video
and audio outputs are according to the input and
output terminals for each mode.
21VR2