50PJ350 Power Supply Troubleshooting
With P813 disconnected from the Main board (P301) attach two 100 Watt light bulbs, attach one end to Vs and the other end to ground.
Apply AC to SC101. If the light bulbs turn on and VS is the correct voltage, allow the SMPS to run for several minutes to be sure it will
operate under load. If this test is successful and all other voltages are generated, you can be fairly assured the power supply is OK.
Note: To be 100% sure, you would need to read the current handling capabilities of each power supply listed on the silk screen on the
SMPS and place each supply voltage under the appropriate load. Then follow the instructions below to completely test turn on sequence.
41
(A) Ground the Auto Gnd Line (Pin 18) will allow the supply to be powered up one section at a time.
(B) Add a 100
Ω
¼ watt resistor from 5V Standby to RL_ON and the AC Det, 17V and 5V Lines on P813 will become active.
(C) Add a 100
Ω
¼ watt resistor from any 5V line to M_ON (Monitor_On) to make the M5V, VS and VA lines operational.
P812 (VS pins 1 and 2) (VA pins
6
and
7
) and (M5V pins 9 and 10).
Note: Placing the two 100 Watt light bulbs from Vs to Ground will assure the power
supply will regulate with a load and no other Abnormal conditions may result.
P301
3
1
7
5
11
9
15
13
17
4
2
8
6
12
10
16
14
18
17V
Gnd
+5V
+5V
Gnd
Gnd
Auto Gnd
B
10
0
Ω
A
M_On
AC Det
17V
Gnd
+5V
Error Det
Gnd
RL
ON
Note: Leave previous installed 100
Ω
resistor in place when adding the next resistor.
Gnd
STBY
5V
STBY
5V
100
Ω
C
When the supply is operational in its normal state the Auto Ground line at Pin 18 of P813 is held at ground by the Main Board.
This Power Supply can be powered on sequentially to test the Controller Chip IC701 operational capabilities and for
troubleshooting purposes.
Disconnect P301 from the Main board and use the holes in that end of the connector to insert the jumper and resistors.
Use Main
Board Side
Pin 1
(Front Right)
Warning: Remove AC before adding or removing any plug or resistor.
July 2010 50PJ350 Plasma
Gnd
VS
100
W
100
W
5
8
or
4
or
Pins
1
2
or
Pins
L601
L602
F101
10A 250V
F302
2.5A
250V
F801
4A 250V
ZD302
D609
ZD401
P812
P813
SC101
T901
T902
T301
VA VS
Test Points
POWER SUPPLY
p/n: EAY60968701
VR502
VA Adj
VR901
VS Adj