Adjustment Instructions; Adjustment Method - LG 50PC55-ZB Service Manual

1. Application Object
These instructions are applied to all of the 50" PLASMA TV,
PD73A Chassis.
2. Note
(1) Because this is not a hot chassis, it is not necessary to use
an isolation transformer. However, the use of isolation
transformer will help protect test instrument.
(2) Adjustment must be done in the correct order.
(3) The adjustment must be performed in the circumstance of
25±5°C of temperature and 65±10% of relative humidity if
there is no specific designation.
(4) The input voltage of the receiver must keep 100-240V~,
50/60Hz.
(5) The receiver must be operated for about 15 minutes prior
to the adjustment.
After RGB Full white HEAT-RUN Mode, the receiver must
O
be operated prior to adjustment.
Enter into HEAT-RUN MODE
O
1) Press the POWER ON KEY on R/C for adjustment.
2) OSD display and screen display PATTERN MODE.
* Set is activated HEAT-RUN without signal generator in
this mode.
* Single color pattern(RED/BLUE/GREEN) of HEAT-RUN
mode uses to check PANEL.
If you turn on a still screen more than 20 minutes (Especially
Digital pattern, Cross Hatch Pattern), an afterimage may occur
in the black level part of the screen.
3. Chancel memory Setting Method
: You can set channel memory by R/C for adjustment.
1) Press ADJ key on R/C for adjustment.
2) Press ENTER key on "System Control3".
3) Press VOL + key on "Channel Recover".
4. PCMCIA CARD Checking Method
: You must adjust DTV 29 Channel and insert PCMCIA CARD
to socket.
1) If PCMCIA CARD works normally, normal signals display
on screen.
But it works abnormally, "No CA module" words display on
screen.
Copyright©2007 LG Electronics. Inc. All right reserved.
Only for training and service purposes

ADJUSTMENT INSTRUCTIONS

Each PCB assembly must be checked by check JIG set.
(Because power PCB Assembly damages to PDP Module,
especially be careful)
5. POWER PCB Assy Voltage
Adjustments
5-1. Test Equipment :
5-2.Connection Diagram for Measuring
: refer to Fig.1

5-3. Adjustment Method

(1) Va Adjustment
1) After receiving 100% Full White Pattern, HEAT RUN.
2) Connect + terminal of D.M.M to Va pin of P12, connect -
terminal to GND pin of P12.
3) After turning VR901, voltage of D.M.M adjustment as
same as Va voltage which on label of panel right/top.
(Deviation; ±0.5V)
(2) Vs Adjustment
1) Connect + terminal of D.M.M to Vs pin of P12, connect –
terminal to GND pin of P12.
2) After turning VR951, voltage of D.M.M adjustment as
same as Va voltage which on label of panel right/top.
(Deviation; ±0.5V)
<50" EAY32929001 only for 50PB56>
(Fig. 1) Connection diagram of power adjustment for measuring
- 6 -
(Va, Vs Voltage adjustments)
D.M.M. 1EA
<50" 6709900020A>
LGE Internal Use Only