LG 42PQ30 Training Manual page 121

Y-DRIVE WAVEFORM
VR601
V Set-Up (Ramp)
Waveform TP
On Y-Drive PWB
160V
A
+ - 5V
0V
V Set-
B
Down
VR401
185us
+
5us
-
50VAC rms 100uS 528V P/P
Connect Scope between Waveform TP on Y-Drive and Gnd
Use RMS information just to check for board activity.
Y-SUSTAIN
P203
P208
P205
All
Floating
Gnd
TP
SET-UP
VSC
TP -
+
-
-VY TP
+
R201
VR501
R520
VSC
Scan Scan 1,2
5V FG 4,5 Fusable
VR502
FL1
Link
-VY
+
FS501 (17V)
- 125V 4A
C18
FL1
P202
5V Fuse
Pin Label STBY Run
Floating
1 Gnd Gnd Gnd
Ground
2 Gnd Gnd Gnd
3
Gnd Gnd Gnd
4 nc nc
5
*Va 0V 60V
6 0V
*Va 60V
7 *Va 0V 60V
To Check 5V to the Y Drive,
*Varible according to Panel Label
measure across capacitor C18.
The voltage is supplied thru FL1.
LEFT X DRIVE
P201 P202
TCP TCP
P811
4mS
M5 (9,10)
Va (6,7)
Vs (1,2)
P201 Y-SUS and P811 SMPS
Pin Label STBY Run
1 Vs 0V *193V
2 Vs 0V
*193V
3 nc nc nc
4 Gnd 0V 0V
5 Gnd 0V 0V
6 Va 0V *60V
P201
7 Va 0V *60V
8 Gnd 0V 0V
FS202
9 M5V 0V 5V
(VS)
10 M5V 0V 5V
250V 4A
*Variable according to Panel Label
P206
Pin Label STBY Run
1 er com 0V *94.9V
2 er com 0V *94.9V
3 nc nc nc
4
Gnd Gnd Gnd
5 1) 5.4V
Gnd Gnd Gnd
VR601
P206
2) 5V
6
nc nc
nc
3) 1.3V
7 Vs *193V
0V
4) 0V
Vs *193V
8 0V
VR401
SET-DN
Note: IC221 (3.3V Regulator)
routed out P161 / P162 to X-PWBs
IC221
FS201 (5V) FS203 (VA)
125V 4A 125V 10A Pin 1 (4.95V)
Pin 2 (3.3V)
Pin 3 (0V)
Fusable Links
IC221
FL111 FL112
P101
15V and 5V
5V Fuses
Ribbon Cable
Y-Drive Signals
P111
P202
With the unit on. If D201
does not blink on/off. Check
5V supply. If present replace
the Control PCB
Va
P211 / P311
nc
Pin Label STBY Run
1 Gnd Gnd Gnd
2 Gnd Gnd Gnd
3
nc nc nc
4
*Va 0V 60V
5 *Va 0V 60V
*Varible according to Panel Label
Note: 3.3V for X boards originates
P233
from IC221 on the Control board
P204
P203 P205
TCP TCP TCP
42PQ30 CIRCUIT INTERCONNECT DIAGRAM
P813
Pin Label STBY Run No Load
1, 2 17V 0V 17V 17V
3, 4 Gnd Gnd Gnd Gnd
5, 6 12V 0V 12V 12V
7, 8 Gnd Gnd Gnd Gnd
9, 10 9, 10 5V 5V 5V
VS Adj
11, 12 11, 12 5V 5V 5V
13, 14 13, 14 Gnd Gnd Gnd
R901
15, 16 15, 16 Gnd Gnd Gnd/nc
17 5V Det 0V 5V 5V
18 AC Det 4.6V 4.6V 5V
19 RL On 0V 3.73V 0V
SMPS PCB
20 Vs On 0V 3.2V 0V
POWER SUPPLY
21 0V 3.26V 0V
M5 On
Auto Gnd
22 0V 0V 5V
23 Stby5V 5V 5V 5V
24 Key On 0V 0V 5V
A/C IN
SC101
Main Front Side Regulators
8V regulator NV RAM HDCP
EDID
3.1V REG
For IC505
IC202
IC805 IC201
IC302
Tuner B+
1,2) 0V
1,2,3,4) 0V 1,2) 0V
5) 0.9V
3,4) 0V
IC503
5) 4.7V 3,4) 0V
6) 1.5V
5, 6) 3.3V
1) 12V
6) 4.7V 5, 6) 3.3V
7) 4.9V
7) 0V
2) 0V
7) 3.3V 7) 0V
8) 3.6V
3) 8V 8) 3.3V
8) 4.7V 8) 3.3V
No
Unplug all connectors. Jump 5V from SMPS
LVDS
Connection
(P813 pins 9~12) to pin 1 of IC211. Observe
P121
LED. If it blinks, most likely Control PWB is OK.
P131
FL111 and FL112 should be checked.
X101
IC211
ROM
Disconnect P201 from the Y SUS Board and
Pin 1 (5V)
Updates
IC231
25 Meg Pin 2 (1.8V) connect a Jumper from Pin 10 of P811 (M5V) to
Pin 3 (0V)
Pin 10 P201 (5V). The 5V will be routed to the
Pin 3 (0V)
Control Board via FS201, Ribbon Cable P101 on
CONTROL PCB
Pin 2 (3.3V)
IC201
Pin 1 (4.95V) the Y SUS Board and FL111 and FL112 on the
IC252
Control Board for Control Board operation
Auto Gen
P101
verification.
FL204
Pin 4 (3.3V)
D201 Pin 11/12 (15V) and Pin 10 (5V)
1V Fuse
Pin 3 (3.3V)
Pin 2 (0V)
Pin 1 (3.3V)
Short across the two points labeled
P161 P162
Auto Gen to generate a test pattern.
If the complaint is no video and
3.3V 3.3V
shorting the points (AutoGen) causes
video to appear suspect the Digital PCB.
X-Drive
Signals
Va Va
Note: 3.3V for X boards originates
P211 P232 P331 P311
from IC221 on the Control board
P206
P301
TCP TCP
SMPS Test – Unplug P813 If all supplies do
not run when A/C is reapplied, disconnect
P811 to isolate the excessive load. This
supply will operate with no external load. For
a proper text, use two (100W) light bulbs in
R502
series to test under a load.
P2
VA Adj
Pin Label STBY Run
1 0V 0.79V
Z SUS Dn
2 Z SUS Up 0V 0.13V
3 Z ER Up 0.19V
0V
4 Z ER Dn 0V 0.4V
5
Z Bias 0V 1.9V
6
Z Enable 0.8V
0V
Z Ramp Dn 1.9V
7 0V
Gnd Gnd Gnd
8
9 Gnd Gnd Gnd
10
+5V 4.9V
0V
+15V 16.9V
11 0V
+15V
12 0V 16.9V
P813
Main Back Side Regulators
5V regulator IC602, IC802,
1.8V MST 1.2V VSB 3.3V MST
Tuner B+ IC803
IC304 IC305
IC502
IC505 1,2,3,4) 0V
1) 0.63V 1) 3.3V 1) 0V
1) 8V 5) 4.6V
2) 1.85V 2) 1.27V 2) 3.4V
2) 0V 6) 4.6V
3) 3.3V 3) 0V 3) 5.0V
3) 3.78V 7) 3.3V
8) 4.6V
P1006
IC503
To keys and IR
IC201
To
Speakers
IC601
IC803
IC802
IC602
P304
P302 P303
TCP TCP TCP
Z-SUS
Signal
41V (AC) rms 400us 200Vp/p
Connect Scope between Waveform TP on Z board and Gnd
Use RMS information just to check for board activity.
Z-SUSTAIN
P6
Z-SUS
Waveform
TP J27
R49
VZB TP
+
Right Side
VZB
R50 R49 or R50
P3
VR8
To Chassis
P7
Gnd
P2
5V
17V
For Regulator
Z-Drive Signals
Voltages
See Chart
LVDS
IC302
IC203
P1002 LVDS
IC304
IC202
IC305
IC201
IC1
Mstar
SW301
X501
IC504
IC502
X1
MAIN PWB
IC805
TU501
TUNER
IC505
Grayed Out ICs are located on Back
RIGHT X DRIVE
P306
P305
TCP TCP