Daewoo VCR MECHANISM UNIT Adjustment of the wave form of Drum Entrance / Exit Fig, Review

ADJUSTMENT OF THE TPAE TRANSPORTING SECTION. (CONTINUED)

H.Adjustment of the wave form of DRUM Entrance / Exit (Fig. 5.8)

Test Point	S/W PULSE TEST PIN	PATH ADJ. FIXTURE
	ENVELOPE TEST PIN	PATH ADJ.FIXTURE
Measurement Equipment	OSILLOSCOPE
Adjustment	VR CONTROL	PATH ADJ.FIXTURE
	S/T GHIDE ROLLER	TAPE TRANSMISSON SECTION

a.Connect the PT01 on the MAIN CIRCUIT BOARD with a PATH ADJ.FIXTURE.

b.Play back an ALIGNMENT TAPE(DN-2 : MONO- SCOPE signal)

c.Connect the S/W PULSE TEST PIN on the PATH ADJ. FIXTURE with a CHANNEL-1 SCOPE PROBE.

d.Connect the VIDEO OUT on the MAIN CIRCUIT BOARD with a CHANNEL-2 SCOPE PROBE(1V/div).

e.Turn the VR CONTROL on the PATH ADJ.FIXTURE clockwise or counterclockwise until the signal shape of ENVELOPE has the constant thickness.(Fig.5.8)

f.Adjust the S/T GUIDE ROLLER if the thickness of the ENVELOPE signal is not uniform.

FIg.5.8 Fine adjustment of the ENVELOPE at the DRUM

ENTRANCE/EXIT

I. REVIEW	PLAY(Fig. 5.9)
Test Point	S/W PULSE TEST PIN	PATH ADJ. FIXTURE
	ENVELOPE TEST PIN	PATH ADJ.FIXTURE
Measurement Equipment	OSILLOSCOPE
Adjustment	VR CONTROL	PATH ADJ.FIXTURE
	S/T GHIDE ROLLER	TAPE TRANSMISSON SECTION

BOARD with a CHANNEL-2 SCOPE PROBE(1V/div).

e.Make the VR CONTROL on the PATH ADJ.FIXTURE to the center to maximize the ENVELOPE signal.

f.Play back the REVIEW MODE about 15 secong and alter the mode to PLAY MODE.

g.Check whether the ENVELOPE waveform restore to its original form within 3 second when the REVIEW mode is changed to PLAY mode.

h.If the requirement of “g” is not satisfied, Check the run- ning status of tape on the lower part of T GUIDE POST and adjust the S/T GUIDE ROLLER precisely.

FIg.5.9 Waveform change when the mode altered

(REVIEW ↔PLAY)

J.Checking for the J.AUDIO output waveform (Adjustment of AC HEAD TILT & Height)

Test Point	AUDIO OUTPUT	AUDIO OUTPUT JACK
Measurement Equipment	AUDIO LEVEL METER

a.Connect the AUDIO output jack with an AUDIO LEVEL METER.

b.Playback an Alignment Tape (DN-1:Color Bar 1KHz Signal)

c.Check if the AUDIO output signal level is over -9~- 3dBm.

d.If the requirement of “c” is not satisfied, readjust the AC HEAD TILT and the HEIGHT until the AUDIO output is maximized. (Fig. 5.2, 5.3)

a.Connect the PT01 on the MAIN CIRCUIT BOARD with a PATH ADJ.FIXTURE.

b.Play back an ALIGNMENT TAPE(DN-2 : MONO- SCOPE signal)

c.Connect the S/W PULSE TEST PIN on the PATH ADJ.FIXTURE with a CHANNEL-1 SCOPE PROBE.

d.Connect the VIDEO OUT on the MAIN CIRCUIT

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