50PM4700-DA (CHASSIS:PB22A) - LG TV Service Manual (repair manual). Page 7

Read LG 50PM4700-DA (CHASSIS:PB22A) Service Manual online

- 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
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.
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)
RS-232C COMMAND
[CMD           ID        DATA]
Meaning
wb
00
00
Begin White Balance adj.
wb
00
ff
End  White  Balance  adj.  (internal 
pattern disappears)
Page of 74
Display

Click on the first or last page to see other 50PM4700-DA (CHASSIS:PB22A) service manuals if exist.