Adjustment Notice: All adjustments (DC or Waveform) are adjusted in WHITE WASH. Customer’s Menu, Select “Options”, select “ISM” select “WHITE WASH”
It is critical that the DC
Voltage adjustments be checked when;
1) SMPS, Y-SUS or Z-SUS board is replaced.
2) Panel is replaced, Check Va/Vs since the SMPS does not come with new panel.
3) A Picture issue is encountered.
4) As a general rule of thumb whenever the back is removed.
ADJUSTMENT ORDER “IMPORTANT” DC
VOLTAGE ADJUSTMENTS
1) POWER SUPPLY: VS, VA (Always do first)
2) Y-SUS: Adjust –Vy, VSC
3) Z-SUS: Adjust Z-Bias (VZB)
WAVEFORM ADJUSTMENTS
1) Y-SUS: Set-Up, Set-Down
The Waveform adjustment is only
necessary
1) When the Y-SUS board is replaced
2) When a “Mal-Discharge” problem is encountered
3) When an abnormal picture issues is encountered.
SWITCH
MODE POWER SUPPLY [SMPS] SECTION
This Section of the Presentation
will cover troubleshooting the Switch Mode Power Supply for the Single Scan
Plasma. Upon completion of the section the technician will have a better
understanding of the operation of the Power Supply Circuit and will be able to
locate voltage and test points needed for troubleshooting and alignments.
DC Voltages developed on the SMPS
Adjustments VA and VS
Always refer to the Voltage Sticker
located on the back of the panel, in the upper Left Hand side for the correct
voltage levels for the VA, VS, -VY, VSC, and Z Bias as these voltages will vary
from Panel to Panel even in the same size category.
Set-Up and Ve are just for Label location identification and are not adjusted
in this panel.
SMPS
Part Number: EAY60968701
Check the silk screen label on the top center of the Power Supply board to
identify the correct part number. (It may vary in your specific model number).
Operation
of this Power Supply.
The Switch Mode Power Supply Board Outputs to the :
Y-SUS
Board
VS: Drives the Display Panel’s Horizontal Electrodes.
VA: Drives the Display Panel’s Horizontal Electrodes.
M5V: Used to develop Bias Voltages on the Y-SUS then routed to the Control board and then to the Z-SUS Board.
Z-SUS
Board
VS: VS is routed to the Y-SUS first then to the Z-SUS board which Drives the Display Panel’s Horizontal Electrodes.
Main
Board
STBY 5V: Microprocessor Circuits
17V: Audio B+ Supply, Tuner B+ Circuits 5V Signal Processing Circuits
Also AC-Det (if missing, shuts of TV in 10 seconds) and Error-Det (not used)
Adjustments
There are 2 adjustments located on the Power Supply Board VA and VS. The M5V is pre-adjusted and fixed. All adjustments are made referenced to Chassis Ground. Use “Full White Raster” 100 IRE
VS:
VR901
VA:
VR502
Power
Supply Basic Operation
AC Voltage is supplied to the SMPS Board at Connector SC101 from the AC Input assembly, routed to the Standby 5V supply. The STBY5V (standby) is B+ for the Controller chip on the back of the board (IC701) on the SMPS and output at P813 pins 13 and 14 then sent to the Main board for Microprocessor (IC1) operation (STBY 3.46V RUN 5.14V).
When the Microprocessor (IC1) on
the Main Board receives a “POWER ON“ Command from either the Power button or
the Remote IR Signal, it outputs a high (2.43V) called RL_ON at Pin 15 of P813.
This command causes the Relay Circuit to close both Relays RL101 and RL103
routing AC to the Bridge Rectifier D101 which then routes the primary voltage
to the PFC circuit (Power Factor Controller) 388V which can be read measuring
voltage at Fuses F302 and F801 from “Hot” Ground. AC Detection (AC Det) is
generated on the SMPS, by rectifying a small sample of the A/C Line and routed
to the Controller (IC701) where it outputs at P813 pin 16 (4.44V) and sent to
P301 to the Main Board where it is sensed and monitored by the Main
Microprocessor (IC1). If AC Det is missing the set will come on, but shut off
in 10 seconds.
When RL_ON arrives, the run voltage +5V source becomes active and is sent to
the Main Board via P813 (5.17V at pin 5, 6 and 7). The (Error Det) from the
SMPS Board to the Main Board can be measured at pin 8 of P813 (2.85V STBY and
4.90V RUN), but it is not used. The RL-ON command also turns on the 17V (Audio
B+) which is also sent to the Main Board. The 17V Audio supply outputs to the
Main board at P813 pins 1 and 2 and used for Audio processing and amplification.
The next step is for the
Microprocessor IC1 on the Main Board to output a high (3.29V) on M_ON Line to
the SMPS at P813 Pin 17 which is sensed by the Controller IC701, turning on the
M5V line and outputs at P812 pins 9 and 10 to the Y-SUS
board.
The Controller (IC701) also uses
the M_ON line to turn on the VA and the VS supplies. (Note there is no VS On
Command in this set). VS is output at P812 to the Y-SUS board P210. (VA pins 6
and 7 and VS pins 1 and 2). Note: The Va is fused
on the Y-SUS then routed out P203 to the X-Board Left. VS is also routed out of
the Y-SUS P211 pins 4 and 5 to the Z-SUS P2.
AUTO GND Pin 18 of P813: This pin
is grounded on the Main board. When it is grounded, the Controller (IC701)
works in the normal mode, meaning it turns on the power supply via commands
sent from the Main board. When AUTO GND is
floated (opened), it pulls up and places the Controller (IC701) into the Auto
mode. In this state, the Controller turns on the power supply in stages
automatically. A load is necessary to perform a good test of the SMPS if the
Main board is suspect.
50PJ350
SMPS STATIC TEST UNDER LOAD
Using 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.
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.
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.
Warning: Remove AC before adding or removing any plug or resistor.
Note: Leave previous installed 100Ω resistor in place when adding the next resistor.
Ground the Auto Gnd Line (Pin 18)
will allow the supply to be powered up one section at a time.
(B) Add a 100Ω 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 100Ω 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).
SMPS
Connector P813 Identification, Voltages and Diode Check
a Note: The 17V, 5V, AC_Det and
Error Det turn on when the RL_On command arrives.
b Note: The M5V, Va and Vs turn on when the M_On (Monitor On) command arrives.
c Note: The Error Det line is not used in this model.
d Note: If the AC Det line is Missing, the TV will shut off after 10 seconds of
operation.
e Note: Pin 18 is grounded on the Main board. If this line is floated, the SMPS
turns on Automatically when AC is applied.
SMPS
Connector SC101 and P812 Identification, Voltages and Diode Check
Diode Mode Readings taken with all connectors Disconnected. DVM in Diode Mode.
