HORIZONTAL OSCILLATOR DISABLE CIRCUIT
This chassis employs a special circuit to protect against excessive high voltage and beam current. If, for any reason, the high voltage
and beam current exceed a predetermined level this protective circuit activates and detunes the horizontal oscillator that limits the high
voltage. The over-voltage protection circuit is not adjustable. However, if components indicated by the symbol on the schematic in
either the horizontal sweep system or the over-voltage protection circuit itself are changed, the operation of the circuit should be
checked using the following procedure:
Equipment needed to check the disabled circuit:
1.
High voltage meter (0 ~ 50kV)
2.
Variac or isolation transformer
3.
D.C. current meter
4.
Digital voltmeter
PREPARATION
1.
Connect receiver to A.C. 120 Volts. Do not turn ON.
2.
Connect HIGH VOLTAGE meter to 2nd anode (H.V. button).
NOTE
Use cold ground for negative lead.
3.
Connect the ammeter serial from the flyback anode lead to the picture tube anode socket.
PROCEDURE
1.
Apply a monoscope or white pattern.
2.
Confirm that beam current is 2.0mA.
3.
Adjust VR524 so that high voltage is 29.5kV ± 0.3kV.
4.
Adjust VR538 so that digital meter reads 2.3 ± 0.05V
5.
Confirm that high voltage protector (SOS) operates at 34.0kV or less by adjusting VR524.
6.
Turn VR524 counter clockwise, turn tv on and apply a monoscope or white pattern.
7.
Adjust VR524 so that high voltage meter reads 29.5 ± 0.3kV.
8.
Once the adjustment is completed, apply a bond on VR524 and VR538. Confirm B+ 142V ± 6.0V with 120V A.C. applied.
NOTE
If high voltage is not within the specified limit the cause must be determined before the receiver is returned to the owner.
3 Receiver feature table
FEATURE/MODEL
CT-27HL15N/UN
CHASSIS
DP435
MICRO
256K
MENU LANGUAGE
ENG/SPAN/FR
CLOSE CAPTION
X
V-CHIP (USA/CANADA)
X
VIDEO INPUT SKIP
X
CHANNEL COUNT
181
REMOTE CONTROL (W/LIGHT)
EUR7613ZC0
CRT SUPPLIER
SAMSUNG
FAMILY
GN1M
COMB FILTER
3D-Y/C
HEC/VEC (X=BOTH)
X
VM
X (SELECTABLE)
V/A NORM (X=BOTH)
X
COLOR TEMP
X
AI PICTURE
X
PRESET/INPUT LABELING
X
VIDEO PICTURE MEMORY
X
HDTV MONITOR
1080i
PROGRESSIVE SCAN DOUBLER
X
EDTV MONITOR
480p
STEREO/SAP WITH dbx NR
X
Page 5 of 32
7/7/2008
http://tsn.pstc.panasonic.com/viewing/NA/CT-27HL15N/SIMP/MTNC050426A1/doc/MTN...
