CRT (ITC008) Troubleshooting Guide

FOREWORD This troubleshooting guide is designed to aid the service technician in troubleshooting the ITC008 chassis. It will provide general information on circuit operation, troubleshooting procedures, and some common failures reported to Thomson’s Tech-Line. The troubleshooting procedures may include circuit verification procedures used to eliminate a circuit area from the troubleshooting steps. When using the circuit verification procedures, care must be exercised to prevent further damage to the set. Reference material referred to by this manual includes: •

ESI service data

•

Training Manual

•

Parts Finder (for Part Numbers)

SAFETY INFORMATION CAUTION Safety information is contained in the appropriate Service Data. All product safety requirements must be complied with prior to returning the instrument to the consumer. Servicers who defeat safety features or fail to perform safety checks may be liable for any resulting damages and may expose themselves and others to possible injury. All integrated circuits, all surface mounted devices, and many other semiconductors are electrostatically sensitive and therefore require special handling techniques.

First Edition - First Printing Copyright 2005 Thomson, Inc. Trademark(s)® Registered Marca(s) Registrada(s) RCA and the RCA logos are trademarks of THOMSON S.A. used under license to TTE Corporation Printed in U.S.A.

Prepared by Thomson, Inc for TTE Technology, Inc. Technical Training Department, INH905 PO Box 1976 Indianapolis, Indiana 46206 U.S.A.

Contents FOREWORD .................................................................................... 3 SAFETY INFORMATION CAUTION ................................................. 3 Troubleshooting Fundamentals ..................................................... 5 ITC008 Shutdown............................................................................ 7 XRP EHT Shutdown ................................................................... 8 Over Voltage / Over Current Shutdown (Pincushion).............. 8 +12Vr Shutdown ......................................................................... 8 I2C Bus Communication Shutdown ......................................... 8 Shutdown Troubleshooting Flow Chart ................................... 9 ITC008 Power Supply Troubleshooting ....................................... 10 Dual Voltage Regulator IP030 ................................................. 12 IT008 Deflection Troubleshooting ............................................... 13 Vertical Deflection Troubleshooting ....................................... 14 Horizontal Defleciton Troubleshooting .................................. 16 Alternate Vertical Troubleshooting Information .................... 18 ITC008 Pincushion Shutdown Troubleshooting ......................... 19

Page 4

This troubleshooting guide covers several circuit areas. These areas are related to dead set or shutdown type symptoms only. Circuit areas are: •

Power Supply

•

Deflection (Horizontal and Vertical)

•

Pincushion Shutdown

•

Shutdowns

Troubleshooting Fundamentals One definition of troubleshooting is the diagnosis and repair of malfunctions in electronic equipment using “Logical Analysis” and “Systematic Checks”. The key phrases of this definition are Logical Analysis and Systematic Checks. Without the application of these two principles, troubleshooting complex electronic circuitry is, at best, a hit or miss proposition. It’s also known in some circles as “Shot-Gunning”.

It’s important to remember that troubleshooting is something of an art form and is as much a mental process as it is checking waveforms and voltages. In order to effectively troubleshoot electronic equipment there are several skills the technician must have.

The technician must have: •

A solid understanding of basic electronics. He or she must understand how a transistor, resistor, capacitor, coil, diode, etc. work. They must also understand AC and DC circuits. Even with the best test equipment, without this basic understanding of electronics, the technician is only guessing as to the cause of a malfunction.

•

A basic knowledge and understanding of how all the parts of the instrument function together and how they affect each other. This overview of system operation is necessary in order to understand how the individual circuits can affect the overall operation of the equipment. This is necessary in order to be able to associate a malfunction or symptom with a circuit. In other words, could the suspected circuit cause the specific type of symptom seen?

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When discussing troubleshooting techniques or principles there are a couple of things that should be kept in mind. First, no one can teach a technician the best way to troubleshoot. Troubleshooting is a skill that’s very individualistic. This means that each and every technician will troubleshoot the same problem or malfunction differently. That doesn’t mean one method is right and the other is wrong, just that there are many different ways of solving a problem and that’s what troubleshooting is all about….Problem Solving. However, there are some basic steps and guidelines that can help a technician get started. A skilled technician will develop his or her own style with time and experience.

In most cases troubleshooting can be divided to three basic levels or steps:

1. SECTIONALIZE 2. LOCALIZE 3. ISOLATE

SECTIONALIZE; determine which major functional group or section of the instrument contains the fault. Generally, most problems can be sectionalized by carefully analyzing the symptom.

LOCALIZE; determine which major circuit within a section can or cannot cause the exhibited symptom. This usually requires checking major or key test points.

ISOLATION; find and repair the stage and/or component that has failed. This step requires detailed measurement and monitoring of signals and voltages within the suspected circuit area.

To quickly and efficiently diagnose a malfunction, the technician should follow a set sequence of steps each time he services a piece of equipment. There are five (5) basic steps in troubleshooting or symptom analysis.

1. Physical Inspection 2. Operational Check 3. Sectionalize 4. Localize 5. Isolate Page 6

Following these five simple steps and having a basic understanding of electronics along with how the equipment works will organize the technician’s troubleshooting into a logical pattern or sequence and increase their effectiveness as a troubleshooter. Remember, these are only principles and can be interpreted in many different ways. Also, troubleshooting is a very unique skill and is learned by doing. All these principles and concepts can be applied to servicing virtually any type of product or equipment. The five steps of troubleshooting may seem obvious to some or complex to others but with time and experience they will become second nature

ITC008 Shutdown Shutdown consists of: •

An XRP circuit that monitors the heater pulse from pin 12 of LL05.

•

Over voltage and over current shutdown for pincushion

•

+12Vr shutdown

•

I2C Bus Communication shutdown

Determining which shutdown circuit to troubleshoot is the key. There is no quick way and from past experience, one just needs to start the process of elimination and eliminate them one at a time.

Each shutdown has it’s own “trigger”. This “trigger” is what causes the shutdown to occur. More then one “trigger” my feed into a single shutdown circuit. These types of shutdowns seem to be the most difficult to troubleshoot. For example, in the ITC008 pincushion shutdown over current and over voltage are on the same line feeding the shutdown of horizontal drive. In this same shutdown circuit, feedback from the IHVT (LL005) is used to kill drive signal while energy is still being transferred from LL005. In this shutdown there are three signals that can kill horizontal drive and shutdown the set. Knowing how to disable each will aid in troubleshooting what “trigger” is causing the shutdown.

This section will provide troubleshooting tips on how each shutdown “trigger” can be isolated in a safe manner. In some cases there is no way to isolate the trigger therefore, some understanding of the shutdown will help logic out the “trigger”. Other times it is trial and error.

Page 7

XRP EHT Shutdown Use extreme caution when doing this procedure!! Start by disconnecting the CRT anode lead and CRT socket. Then locate JL905 at grid location 8,UU on the main CBA. Unsolder one end. This disables both the EHT and excessive current shutdown for high voltage. Use caution with XRP EHT shutdown disabled and keep on-times to a minimum.

Over Voltage / Over Current Shutdown (Pincushion) This is by far the easiest to disable. The feed back information that causes shutdown comes through connector BF001. By unplugging this connector the shutdown is disabled.

+12Vr Shutdown This is not a typical shutdown circuit but more a lack of run voltage issue. The +12Vr is used as the run voltage for Horizontal driver amp TL033. If this voltage is missing TL033 will start but never run. Supplying the +12Vr from an external DC source verifies the +12Vr as the problem. This voltage should be supplied to the Cathode of DL012 and referenced to cold ground while the set is pulsing or trying to start.

I2C Bus Communication Shutdown With this shutdown it is a trial and error situation. Error codes are logged for communication shutdown but can only be read if the set is operational. Knowing that the Tuner, MAV CBA, and Alert Guard CBA are the only communication problems reported it is safe to use the process of elimination for this shutdown. The Alert Guard CBA is the only one that is of Plug and Play nature. Both the Tuner and MAV CBA will cause shutdown if connected or not. Therefore; trying the Tuner and the MAV are by trial and error.

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Shutdown Troubleshooting Flow Chart Apply AC power and press the power switch.

Try to turn on the set. Dead or Pulsing?

Dead

Troubleshoot Power Supply

Pulsing

Does the set Pulse 3 times and quit or Cycle every 5 sec. continuously

Pulse at 5 Sec Intervals

Does the set have Alert Guard?

NO

YES Cycles 3 Times Disconnect the Alert Guard Module.

Disconnect the Pincushion Connector BF001

Try to turn on the set. Does the set start?

NO

Troubleshoot Horizontal Deflection

Try to turn on the set. Does the set start?

NO

Troubleshoot System Control Communication I2C Bus Tuner and MAV?

YES YES Suspect the Pincushion Module

Suspect the Alert Guard Module

The above flow chart is used to troubleshoot a dead set or shutdown condition. This chart and the troubleshooting sections found in this guide cover those scenarios found during calls to Tech-line. They do not cover all possible scenarios, only the most common or unique ones.

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ITC008 Power Supply Troubleshooting (Dead Set, Power supply voltages missing or incorrect) FP001 DP005 RP006

DP004

DP002 DP003

CP008

18 16

9

RP007

DP025,026 CP024,025 DP027 27V

RP030

15V

12

RP125

DP063

+13.1V DP097

10

RP029 TP023 RP026

DP030 8.2V

IP001 1

3

2

TP022

RP052 IP050 1 3

PG1 DP057 9.1V

TP052 RP054 RP158

RP057 RP151

2

CP022

Pwr Good TP193,192

RP056 RP155

CP040 4 RP041

CP064

11

2

RP040

CP094

RP066

FZP61 3.15A

RP033

RP028

DP093

13

1

RP023 RP027 DP040 27V

RP031 RP020 0.27 Ω

+19.5V CP206 +6.3Vs

DP023

DP033

+21.5V

DP202

CP062

RP132

TP025

S RP021

DP061

FZP93 500mA 3

G

FZP60 3.15A

14

TP020 D

+126V CP080

15

5 Slow Start RP037,038 DP037 CP037,038 CP039

DP080

LP003

RAW B+

Beam Current Sense

Burst Mode IV001 pin 63

NOTE: DP027 will short whenever feedback is lost or an excessive load on the secondary of LP003 is present. This will shut down the power supply. IF DP027 is shorted, check FZP61. If FZP61 is open, check the +13.1V for excessive load and check the feedback circuit (IP001, TP022, and IP050) for proper operation.

1. Check RAW B+, if not OK check the full wave bridge rectifier DP002/003/004/005 and it’s associated components.

2. If RAW B+ OK, check the current sensing resistor RP020. If open, this would indicate there has been a severe over current condition between the drain and source of TP020. Check and replace all defective active components on the primary side of LP003. Check for excessive loads off secondary of LL03 before reapplying AC power.

3. Check for DC voltage and waveform on the gate of TP020. A waveform, like the one on page 11, indicates the oscillator is running. If there is no waveform unsolder the drain of TP020 and check for 7.8Vdc on the gate. 7.8Vdc on the gate of TP020 indicates start-up circuit is working go to step 5. If a waveform is present on the Gate of TP020, the primary switching of the supply is working.

Page 10

Gate of TP020 Waveform Stby Mode

Device

Resistance to Cold GND

DP080 DP061 DP093 DP063

45.7K 1.4M 5K 7K

Resistance Chart for Power Supply

Start-up Circuit Test: Working unit voltages with the Drain of TP020 open: (HOT GND Reference) •

Gate = 7.8V

•

Startup ckt = 8.9V (Measured on TP025 (E))

•

TP025 C = 8.0V, E = 8.9V, B = 8.3V

•

Junction of RP006 and 007 = 32.4V

4. If DC on gate of TP020 is wrong, check TP025, DP027, DP023, RP006, and RP007 and replace if suspect. Hint: 27V on the emitter of TP025 indicates that the base circuit of TP025 is open. Check DP023, RP125, RP132, or open circuit to pin 3 of LP003. If there is 0V on the emitter of TP025 and DP027 is shorted, check the regulation feedback circuit associated with IP001 and IP050.

5. If no waveform on gate of TP020 (DC OK), check TP022, TP023 and their associated components. Replace all transistors if one has failed or is suspect. If TP020 has failed more than likely the other transistors have been stressed and the circuit will self-destruct again when plugged into 120 AC.

6. If TP020 checks OK (with primary circuit pulsing), check IP050 (Reference Regulator) and IP001 (Opto Coupler) and their associated components. Also check for excessive loads of the secondary of LP003.

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Dual Voltage Regulator IP030 There are two output voltages from IP030 but only one is switched. Pin 4 controls the output on pin 8 (7.9V). When pin 4 goes high, there should be 7.9V on pin 8. This is easy to check by simply removing (unsoldering) pin 4 and checking the output. If voltage is present on pins 1 and 2 then pin 8 should be 7.9V if IP030 is working correctly.

The other output on pin 9 is 3.3V. This voltage is used for System Control standby B+ and Pin 6 of IP030 is the reset voltage for IV001 (SysCon). When power is first applied, IV001 turns on the dual regulator (IP030) for a short period of time. During this time Degauss is energized and pin 8 of IP030 is switched on supplying the 7.9V. No relay click could indicate IP030 3.3V problem. +13.1Vs Power Supply Control IP01,IP50

+7.9Vs FZP66 DP57 9.1V RP57

+5Vs

DP36

CP66 1

TP52 RP151

2 1

IP31

2

3

IP030 8 RP153

Dual Reg.

+3.3Vs

9 RP166 6

Burst

63

IV001

+VCC 14

TR02

Pwr ON 1 Reset 60

Hi = Burst & DAM Mode Lo = Energy Mode

+7.9Vs

4

+181Vr

LL05

CRT

DH01 33V

54 56 33

Reset Switch

+33Vr Horiz Out

Horiz Drive/Out

Tuner

+12Vr -12Vr

Vertical

IP030 Troubleshooting 1. Check for 13.1V on pin 1 and 2 of IP030. If the voltage is correct go to step 2. If missing or not correct troubleshoot standby power supply.

2. Unsolder pin 4 of IP030 and check for 7.9V on pin 8. If the voltage is present, go to step 3. If the voltage is low or missing suspect IP030.

3. Reconnect pin 4 and check for 3.3V on pins 6 and 9. If present, go to step 4. If the voltage is low or missing suspect IP030. Page 12

4. With pin 4 of IP030 connected, monitor pin 8 and press the power switch. If 7.8V momintarly comes up, system control and regulator are working correctly, suspect a Horizontal startup problem. If there is no change on pin 8 troubleshoot system control.

ITC008 Deflection Troubleshooting In order to troubleshoot deflection we must first understand where the signals are generated. In the ITC008, IV001 (TV Processor) is used to generate both the Vertical and Horizontal drive signals. The generation of these drive signals depends on several external circuits and proper operation of IV001.

First, being system control, IV001needs to have VCC (Stby), GND, OSC, and RESET to function. Next, some sort of user interface (Remote or FPA) to tell IV001 what to do. IV001 also needs a set of instructions to perform the expected command. This instruction is in the form of “DATA” found in the EEPROM (IR001). The “DATA” is used to set up registers in IV001. These registers include Horizontal timing, Vertical timing, and shutdown settings. Transfer of "DATA" happens each time the set is turned on. Failure to properly transfer the "DATA" will result in a dead set condition.

This troubleshooting section assumes certain sections of IV001 are working correctly. These sections are System Control and Signal Processing.

to Front Panel BR001 IR001

8 +5Vs

EEPROM 64 6 7 KB/LED IR

5,6

21, 22 VDrive

2,3 Clk/Data 61 +3.3V VDD 1 PWR ON

33 Horiz Out

IV001 TV Micro

36 XRP EHT

60 RESET +3.3V VCCD Core 54,56 58,59

GND 12,18,30,41,57

14 +7.9VsD 39

PLL Ckts 15, 19, 16, 17

57 OSC GND IN 58 QV001 OUT 59

Page 13

Vertical Deflection Troubleshooting (No Vertical Deflection)

Setup: Remove CRT Socket, apply AC power and turn on set. When troubleshooting a Vertical deflection problem where the set is operated without deflection it is customary to remove the CRT socket(s) to prevent the CRT from being burnt.

1. Check for –12V on pin 4 of IF001 referenced to cold ground. If missing suspect DL010 and RL010 or a problem with the –12V supply. If correct proceed to step 2.

2. Check for proper waveform on pins 1 and 7 of IF001. These waveforms are generated by IV001. If not correct, troubleshoot IV001 vertical section or suspect EEPROM alignment data corruption. If waveforms are present, check for 48V P-P on pin 5 of IF001. If present IF001 is working and problem is in the yoke circuit. If not go to the next step.

3. Compare the voltage found on pin 2 with that found on pin 6 of IF001. These two voltages should be about .3V different. If they are equal, DF010 should be replaced.

4. Check for –10.3V on pin 3 of IF001. This is the boost circuit for IF001. When this voltage is missing suspect IF001, CF010 and DF010. If correct IF001 is working and problem is in the yoke circuit.

Hint: If set is shutting down and removing DL062 allows the set to operate with out vertical deflection, suspect IF001, DF010, and CF010. These are the most common failures of the Vertical circuit causing the set to shutdown. Also check the +12Vr circuit (RL012 and DL012) off pin 6 of IHVT (LL005).

NOTE: Settings in the EEPROM (Vertical) can also cause shutdown. Misalignment of Vertical Slope (parameter #06) and Vertical Amplitude (parameter #08) can cause the protection signal from the E/W module to activate and shutdown the instrument.

To correct for this problem, temporarily disconnect BL101on the E/W module to restart the instrument and reset both parameters.

Page 14

BF001 to Pincushion

RF06

+7.9Vs

IF001 Vertical Output

Vcc

14

IV001 VDriveB

RV06

BF002

RF02

DF02 RV05 VDriveA

RF08

1

21

PWR AMP

7 RF03

22

RF09

5 DF01 56V

CF09

4 RF07

DF03

RF04 2 CF05

DF10

CF10

DF101 -12Vr

CF08

3

6

+12Vr DF102

-12Vr

RF101 CF101

RF102 Beam Current Limit

Page 15

Horizontal Deflection Troubleshooting (No Horizontal Drive)

1. Unsolder collector of TL35 (Horizontal Output Transistor).

2. Monitor the base of TL35 and press the power switch. The set will cycle until power is pushed again. A horizontal drive pulse should be present at the base of TL35 while it is cycling.

3. If a drive pulse is present on the base of TL35, IV001 and the driver circuit are working correctly. The problem is off the collector of TL35. Suspect Yoke, Yoke return circuit, pincushion, LL05 and the secondary side of LL05.

4. If the drive pulse is missing check for drive at pin 33 of IV001. If missing, suspect CV004, CV005, CV006, CV007, CV008, and RV001 components off of pins 15,16,17, and 19 of IV001. Corrupt data in the EEPROM could also prevent horizontal drive.

5. If drive pulses are present at pin 33 of IV001, check for them at the emitter of TL031. If they are missing, disconnect DL062 and recheck. Drive pulses on the emitter of TL031 with DL062 removed indicates that drive shutdown has occurred (See shutdown troubleshooting section). If drive is present at the emitter of TL031 with DL062 in circuit, check for drive at pin 3 of LL032 (LL033 alt). If drive is present at pin 3 of LL032, suspect LL032 (LL033 alt) or a connection problem with LL032 (LL033 alt). If missing go to next step.

6. Check for 13.0V at the collector of TL033 in standby mode. If missing, suspect RL037 and RL038 or TL033 (shorted). If present suspect DL035, RL034 or the +12Vr source.

NOTE: Pin 33 of IV001 (Horizontal Drive) will have 7.0Vdc when drive is missing. Possible causes of no Horizontal Drive: •

Corrupt EEPROM data

•

+VCC missing at pins 14 and 39 of IV001

•

Internal OSC off frequency. Capacitors on pins 15, 19, 16, and 17 of IV001 effect PLL circuits.

•

XRP detected at pin 36 of IV001

Page 16

BF001

TL62 RL63

+7.9VsA TL060/061 DL62

TL31

CL30

RL07 LL05

RL68

3 to 2 Pincushion 1 CBA

IHVT

from

Anode LL32

TL35

13

5

Focus 6

3

RL36

RL06 RF07

CL21 DL21

TL33

Screen

DL30

RL37

CL35

RL38

8

CL23,25,26 RL25,26 DL25 LL26

RL34

12

+7.6VsD RV73

Vcc 14 33 Hout IV001 36 EHT

3 2 1

BL003

Horiz Yoke

DL12 +12Vr

6

CL13 DL10

from Pincushion CBA

7 +126V

1

10

-12Vr RL10

+7.6VsE

CL11 LL40 +181Vr

RL40 XRP TZ01 DZ01,03,05

Pin 12 LL05

9 Pin 8 LL05

34

Htr Return RL12

BL005

Beam Current Sense to PWR IP050-3

Heater & XRP

11

DL35

+13.1Vr +12Vr

TL50 Buffer

4

1

DL40 CL41

RL41 to 44

+33Vr DL01 33V

Feed Back

Page 17

Alternate Vertical Troubleshooting Information Repeat failure of the vertical output IC (IF001) can be difficult to find and expensive. The following information pertains to troubleshooting the vertical circuit with the vertical yoke disconnected. By unloading the vertical circuit it is possible to make checks to the vertical output IC with out damaging it. 1. Disconnect the CRT socket and BF002 vertical yoke connector.

2. Using the Voltage chart, check for correct DC on all pins of IF001. If a voltage is not correct see the notes section of the Voltage chart for possible causes. Pin No.

1

2

Notes

+.7

Incorrect waveform from IV001 or missing wavefrom. Check for open or shorted components between pin 21 of IV001 and pin 1 of IF001. Check feedback resistor RF006.

+12.2

Check for open circuit from +12Vr source. Remember if the +12Vr is missing the set will shutdown.

-13

This voltage is internally generated by IF001 and pin 4. If missing, suspect IF001 or pin 4 voltage missing. Common parts for incorrect voltage are: IF001, DF010, CF010.

-13

Check DL010 and RL010 off pin 7 of LL005. If RL010 is open check for shorts on the -12Vr source.

5

+1.6

This voltage is controlled by IF001 and the input pins 1 and 7. If pins 1 and 7 are correct suspect IF001, RF006, RF009, and RF007. Voltage High indicates no drive to pins 1 and 7 of IF001.

6

+11.8

This voltage should be lower then pin 2. DF010 is a common failure along with IF001.

+.7

Incorrect waveform from IV001 or missing wavefrom. Check for open or shorted components between pin 22 of IV001 and pin 7 of IF001.

3

4

7

Page 18

Voltage

ITC008 Pincushion Shutdown Troubleshooting Pincushion shutdown occurs when TL101 (Pin Driver) pulls excessive current through RL111. As the current increases so does the voltage. IL101 pin 12 monitors this voltage change and when the voltage exceeds the reference voltage found on pin 13 of IL101, IL101 (comparator) switches states and puts a high on pin 14. This high is sensed by TL061 base turning it on and killing horizontal drive. To defeat this shutdown circuit and troubleshoot the pincushion circuit, disconnect DL062.

Some of the common failures in the pincushion circuit have been: •

DL101

•

DL102

•

DL012

1. Verify the set is in pincushion shutdown by disconnecting BF001. If the set stays on, the pin circuit is causing the shutdown. If the set still shuts down the problem is not with the pincushion circuit.

2. Unsolder DL062 cathode. This removes the shutdown protection. Use caution when operating the set with DL062 disconnected. Short on-time is recommended. DL138 CL144

RL138

RL144

CL138

TL101

IL101 RL134

RL150

PL140 3 2

RL106

BL101

RL131

2 1

CL122

RL145 1

DL121

RL108 RL107

3

LL122

PL141

6 5

7

9 10

8

DL122

RL141

BL103

RL111

3

to 2 CL021 and 1 DL021

RL132

PL143

RL137 DL117 12 13

RL105 RL104

RL110

DL119

DL118 RL118

14 DL113

RL112 RL136

CL123

47V

CL114

RL117 RL113

CL110

RL114

+12.2Vpin RL133

DL114

RL134 +12.2Vpin

Page 19

3. Monitor TL101 (Pin Driver) pin 3 for +18Vdc and 9.5Vp-p waveform and turn on the set. If the voltage is missing or incorrect, suspect he Pincushion Circuit Board Assembly (CBA). If the voltage is high suspect an input signal problem or incorrect adjustment.

Note: This voltage can reach +130Vdc. Caution should be taken if this voltage exceeds +50V. +50V is the over voltage shutdown of the pin circuit. With DL062 disconnected the over voltage shutdown is also disabled. Running the set with voltage in excess of +50V can cause additional damage. Short on time is highly recommended.

Tech-Tip: The Pincushion CBA is a replaceable module, however; troubleshooting the module to component level can be accomplished. One of the common failures has been cold solder connections on BL101. An oscilloscope and multimeter are required to isolate other problems. Keep in mind that the voltage readings found in the schematic may not be exactly what your set has. The pincushion circuit has adjustments for the different screen sizes therefore the voltages and waveforms can be slightly different. For example: TL101 pin 3 shows to be 18.0V, our test set used to develop this troubleshooting guide measured 20.8V. An acceptiable range for the voltage on pin 3 of TL101 would be from +15V to +30V. DL138 CL144

RL138

RL144

CL138

TL101

IL101 RL134

RL150

PL140 3 2

RL106

BL101

RL131

2 1

CL122

RL145 1

DL121

RL108 RL107

3

LL122

PL141

6 5

7

9 10

8

DL122

RL141

BL103

RL111

3

to 2 CL021 and 1 DL021

RL132

PL143

RL137 DL117 12 13

RL105 RL104

RL118 DL113 CL114

RL117 RL113

RL114

+12.2Vpin RL133

DL114

RL134 +12.2Vpin

Page 20

RL110

14 RL112

RL136

CL123

47V DL119

DL118

CL110

NOTES

Page 21

TSG_ITC008