LG 50PM4700 Service Manual page 7

5. Final Assembly adj.
* Caution : Each PCB assembly must be checked by check
JIG set. (Because power PCB Assembly damages
to PDP Module, especially be careful)
5.1. POWER Supply Unit PCB Ass'y Va/Vs
Voltage adjustment.
* Caution : Both Vs and Va voltage adjustment are necessary.
5.1.1. Model name
: PB22A
5.1.2. Va/Vs Adjustment Procedure
(1) Connect positive(+) terminal of DMM to Vs/Va pin, connect
negative(-) terminal to GND.
(2) Turning 'Vs/Va Adjust' and adjust Vs/Va voltages to a value
which is written on a right/top label of a module.
(deviation ; ±0.5V)
* Caution : Each Power Supply Unit PCB assembly must be
checked by check JIG set. (Because power PCB
Ass'y damages to PDP Module, especially be
careful)
* Caution : Set up "RF mode(noise)" before a voltage adjust-
ment.
5.2. White Balance adj.
5.2.1. Overview
■ W/B adj. : Objective & How-it-works
- Objective: To reduce each Panel's W/B deviation
- How-it-works: When R/G/B gain in the OSD is at 192,
it means the panel is at its Full Dynamic
Range. In order to prevent saturation of
Full Dynamic range and data, one of R/G/B
is fixed at 192, and the other two is lowered
to find the desired value.
5.2.2. Equipment
(1) Color Analyzer : CA-210 (NCG: CH 9 / WCG: CH12 /PDP
Module:CH10)
(2) Adj. Computer (During auto adj., RS-232C protocol is
needed)
(3) Adj. R/C
(4) Video Signal Generator MSPG-925F
720p/216Gray(Model:217, Pattern:78)
→ Only when internal pattern is not available
■ Color Analyzer Matrix should be calibrated using CS-1000
Copyright © LG Electronics. Inc. All rights reserved.
Only for training and service purposes
5.2.3. Equipment connection map
5.2.4. Adj. Command (Protocol)
■ Protocol
<Command Format>
- LEN: Number of Data Byte to be send
- CMD: Command
- VAL: FOS Data
- CS: Checksum of sent Data
- A: Acknowledge
Ex) [Send: JA_00_DD] / [Ack: A_00_okDDX]
■ RS-232C Command used during auto-adj.
RS-232C COMMAND
[CMD ID DATA]
wb 00 00
wb 00 ff
Ex) wb 00 00 -> Begin white balance auto-adj.
wb 00 10 -> Gain adj.
ja 00 ff -> Adj. data
jb 00 c0
...
...
wb 00 1f -> Gain adj. complete
*(wb 00 20(Start), wb 00 2f(End)) -> Off-set adj.
wb 00 ff -> End white balance auto-adj.
5.2.5. Adj. method
5.2.5.1 Auto adj. method
1) Set TV in adj. mode using POWER On Key
2) Zero calibrate probe then place it on the center of the
Display
3) Connect Cable(RS-232C)
4) Select mode in adj. Program and begin adj.
5) When adj. is complete (OK Sign), check adj. status per
mode
(Warm, Medium, Cool)
6) Remove probe and RS-232C cable to complete adj.
■ Adj. must begin w/ command "wb 00 00", and end w/"wb 00
ff"and adj. offset if needed.
■ Offset adjust limit value.
Offset Min = 34 (Decimal)
Offset Max = 94 (Decimal)
- 7 -
Meaning
Begin White Balance adj.
End White Balance adj. (internal
pattern disappears)
LGE Internal Use Only