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CONTENTS1 2 Analyzing The HV Circuits With The VA62A Analyzing The Horizontal Output Pulse With The Waveform Analyzer 3 4 The TVA92s Horizontal Output Tests Understanding the LC103s In-Circuit Capacitor Test 5 Understanding Horizontal Output Stages of Computer Monitors

Analyzing The Horizontal Output Pulse With The Waveform AnalyzerOf all the TV waveforms you have to analyze, the horizontal output transistor collector pulse is the most important because this output pulse is used to perform many other functions than to just sweep the CRT beam horizontally. It can easily be said that the horizontal output transistor is the heart of a TV. Let's take a careful look at nine of the key functions this all-important horizontal output waveform is responsible for, how to fully analyze it, and some possible problems. The horizontal output stage is practically responsible for the complete and efficient operation of the entire TV. The waveform at the collector of the horizontal output transistor is the most important waveform you should check on every TV before you begin changing parts, and after every TV is repaired . sensitive position and hook up to the horizontal output transistor collector, there is no need to panic as no damage will result. 1) Connect the TV AC line to an isolation transformer, such as the Sencore PR57 POWERlTE. The isolation transformer protects you and your equipment from electrical shock and damage by isolating the HOT chassis from you and your Waveform Analyzer . 2) Hook up the probe ground to the TV chassis ground, then connect the probe to the collector of the horizontal output transistor.

Looking At The Horizontal Output Pulse With In Three Simple StepsSencore's Waveform Analyzers use a highly accurate low capacity probe network that lets you safely measure the horizontal output transistor and other pulse waveforms to 2,000 volts (DC + peak AC). Even if you should happen to accidentally leave your Waveform Analyzer input attenuator in its most

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Fig. 1: The horizontal output pulse is responsible for the efficient operation of the TV.

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3) Adjust the vertical volts per division control to the 200 volts position. Switch your time base control all the way down to the video preset position. Push in the horizontal preset button and you will see waveforms that include two lines of video information.

Fig. 3: Two common faulty waveforms which cause problems with the operation of a TV.

Fig. 2: A typical horizontal output pulse.

lines in the video picture. Look for a shorted secondary power diode, shorted IHVT diodes or shorted windings. The trace time should be clean of any noise before performing the measurements to follow .

How Important Is The Duration Measurement Of The Horizontal Output Transistor Waveform?Of all the horizontal output transistor waveform parameters, theduty-cycle measurement tells you the most. Because of the many jobs that this critical circuit performs, TV manufacturers carefully specify the horizontal output transistor duty-cycle or time duration in exact microseconds as follows: Retrace time: 11.5 - 16 microseconds Trace time: 47.5 - 52 microseconds They make these specifications for a very good reason. If the time duration (dutycycle) is too short during retrace, speed and excessive voltage will be developed; therefore, excessive power will be dissipated. This generates heat which will cause TV parts damage in time. IMPORTANT: Always refer to the manufacturers' schematic or literature for the particular chassis timing. The Waveform Analyzer is especially equipped to measure portions of a waveform with the DELTA TIME feature.

What To Look For In This WaveformBefore you do any measurements, take a second or two to look over the waveform itself. It should look just like the horizontal waveform in Figure 2. The waveform should be symmetrical in shape during pulse retrace time. If it is not, look for a change in the value of the horizontal output transistor stage timing capacitors, or an excessive load on a B+ supply. The waveform should be symmetrical before you proceed with testing . The trace or scanning on time'' of the transistor should also be relatively clean. Any excessive ringing is a clear indicator of deflection system problems such as a cracked integrated high voltage transformer (IHVT) core or open IHVT windings. The trace must be clean before you analyze the pulse any further. If it is not, look for other noise pulses riding along during the trace time. They could be causing faint noises or drive

Measuring The Waveform Parameters (Automatically)You'll need to make four measurements (along with the waveshape covered earlier) of the horizontal output waveform to be sure that it is operating safely or when you are troubleshooting the horizontal section of the TV: FIRST: Push the DCV button for fully autoranged DV voltage measurements. SECOND: Push the VPP button for automatic peak-to-peak measurements. THIRD: Push the FREQ button for automatic and noise free frequency measurements. These three measurements are the first ones to be made. They tell you the condition of the regulated B+ supply, and that the TV is not in the shut-down mode. The next measurement is used to help prevent future component failures.

To make this important measurement: 1. Align the pulse by using the VOLTS/DIVISION and the CAL. knobs so the top of the retrace pulse is on the 100% graticule marking. 2. Select the dual channel mode by pushing the A & B button. 3. Switch the CHANNEL B INPUT COUPLING switch to ground, and align the trace with the VERTICAL POSITION control so it lies on the 10% graticule marking. 4. Press the DELTA TIME button, 5. Adjust the DELTA BEGIN knob so the left-side of the intensified trace aligns with the left-side intersection of the CHANNEL A and CHANNEL B traces (Figure 4).

What If The Horizontal Output Was Only 5 Microseconds Off?Suppose you measure 9 microseconds instead of 14 microseconds for the retrace pulse. On a TV with this type of problem, the peak-to-peak value could be good, the DC reading could be close, and the waveform would look close enough. Even the frequency could be right on 15,734 Hz. This TV will work for a while. Shifting the retrace duty cycle 5 microseconds does not look like much, or even sound like much. But, to the horizontal output system, it sees a 35.7% reduction in retrace time meaning that retrace is faster and this generates higher voltage that means the horizontal output transistor is on just a little longer at full scan conduction. Increased conduction time means increased heat.

Increased scan time means increased scan derived power supply levels. The power supply capacitors have a longer time to charge and reach higher voltages. All the circuits are now stressed and must work at this higher voltage.

Isolate Start-up and Shut-Down Problems With The Horizontal Output PulseThe CRT can be used to watch for an instantaneous start-up pulse. Simply connect the Waveform Analyzer and preset the CRT controls as described earlier. Then, watch the CRT as you apply power to the TV's circuitry. If you see a pulse appear then disappear your start-up circuitry is operating correctly and the set is in the shut-down mode. If this happens, you have to service the chassis in a powered down condition., at either half the normal B+ level, supplied separtately, or reduce the AC input power to half power (60 VAC) and monitor the collector of the horizontal output transistor with your scope.

NOTE: If the chassis uses a switch mode power supply (SMPS) as the B+ source, you need to determine if the SMPS is defective, or if the porblem is on the horizontal output stage. Refer to Tech Tip #205 "Identify SMPS Problems" for information on how to do this.

Fig. 4: The time duration measurement of the retrace puse should be made from the 10% to 10% levels.

For More Information, Call Toll Free 1-800-SENCORE (1-800-736-2673)

6. Adjust the DELTA END knob to align the right-side of the intensified trace with the right-side intersection of the two traces.3200 Sencore Drive, Sioux Falls, SD 57107

7. Read the digital display directly in microseconds to see that you are within 11.5 to 16 microseconds .

Fig. 5: The digital display shows the timing.

Form 4968 Printed In U.S.A.

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The TVA92s Horizontal Output TestsThis Tech Tip presents a logical, step-bystep procedure for using the TVA92s Horizontal Output Tests. While these tests can be used individually, this test sequence gives you the best opportunity to safely identify different types of horizontal circuit defects. If you need additional information on how the horizontal output stage operates or would like an indepth explanation of each test, please refer to the following Tech Tips: #207 Understanding the TV Horizontal Output Stage #208 Making Horizontal Output Dynamic Measurements #209 Understanding the TVA92s Horizontal Output Load Test #210 Understanding the TVA92s Horizontal Output Device Sub & Drive. for using the TVA92s Horizontal Output Tests. I. HORIZ OUTPUT LOAD TESTS AC power removed from the chassis (TV Off) A. Check current draw - mA B. Check output pulse time - uS II.HORIZ OUTPUT DYNAMIC TESTS AC power applied to the chassis (TV On) A. H.O.T. removed, HORIZ DEVICE SUB & DRIVE off 1.Check unloaded B+ power supply - DCV 2.Check for horizontal drive to the H.O.T. - INPUT DRIVE B. H.O.T. removed, HORIZ DEVICE SUB & DRIVE on 1.Check current draw for excessive load - DEVICE SUB CURRENT 2.Check loaded B+ power supply - DCV 3.Check flyback pulse amplitude PULSE PPV 4.Check flyback pulse time PULSE TIME uS C. H.O.T. installed, HORIZ DEVICE SUB & DRIVE off 1.Monitor B+ power supply DCV 2.Monitor flyback pulse amplitude - PULSE PPV 3.Monitor flyback pulse time PULSE TIME uS expect, and what to do when a bad reading is indicated. This procedure covers the most common results and defects. I.Horizontal Output Load Tests The first TVA92 Horizontal Output Tests to perform are the Load Tests. These two tests give an indication of any major defects in the horizontal stage. During the Load Tests the TVA92 supplies a B+ voltage at approximately 10% of normal to the horizontal output stage

CAUTIONThe HORIZ OUTPUT LOAD TESTS produce flyback voltages at the collector of the chassis horizontal output transistor and the flyback secondaries. Do not come in contact with energized circuit points during the Load Tests. A. Current mA 1. Remove power from the TV. These tests should never be performed with AC power applied to the chassis. The load tests can be performed with the H.O.T. in or out-of-circuit. If you find the H.O.T. is shorted, remove it and proceed with the Load Tests. 2. Connect the RINGER/LOAD TEST leads as follows: black lead to the H.O.T.s emitter or equivalent connection if the H.O.T. is removed, yellow lead to the H.O.T.s collector or equivalent connection if the H.O.T. is removed, and orange to the B+ connection on the flyback. 3. Set the HORIZ OUTPUT TEST selector to HORIZ OUTPUT LOAD TEST mA and note the current reading on

Recommended TVA92 Horizontal Output Tests ProcedureThe following outline presents an overview of the recommended procedure

Performing the TVA92 Horizontal Output TestsThe following procedure is a detailed look at the above outline. It describes how to do the tests, what readings toFig. 1: Controls used to perform the HORIZ OUTPUT TESTS.

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TVA92HORIZ OUTPUT TESTSRINGER TESTS YOKE & FLYBACK SWITCHING XFORMER HORIZ OUTPUT LOAD TESTuS

DYNAMIC TESTS DCV PULSE PPV PULSE INPUT DRIVE

S

mATV OFF

TV ON

DEVICE SUB CURRENT

HORIZ OUTPUT DEVICE SUB & DRIVE(CURRENT LEVEL)

0

SUB ON

OVERLOAD

OFF

1.5A MAX

(Orange)

OFF: TVS HORIZ OUTPUT ACTIVE ON: TVS HORIZ OUTPUT SUBISTITUTED

RINGER/LOAD TESTS

DYNAMIC TESTS1500V MAX

!ASSISFLOATING GROUND 1000V ISO

g. 2: Connections to perform the HORIZ OUTPUT LOAD TESTS.

the LCD. The acceptable range is 5-80mA. 4. A reading of greater than 80mA indicates excessive current. To isolate the defect, disconnect the yellow clip lead from the collector and note the current reading. a) DC leakage is indicated if the current stays above 15mA. The defect is caused by a DC leakage path on the primary side of the flyback, such as a damper diode, retrace capacitor or leaky component in the B+ line. b) AC leakage is indicated if the current falls below 15mA. A defective IHVT, horizontal yoke, or secondary loading can cause a short of this type. ote: A reading close to or above 250mA ndicates a direct DC short to ground, sually caused by a shorted H.O.T. or amper diode. 5. A reading of less than 5mA or dashes indicates an invalid connection or open in the circuit. Be sure the mA reading is within the acceptable range before proceeding to the Dynamic Test.

B.Timing uS 1. Set the HORIZ OUTPUT TESTS selector to HORIZ OUTPUT LOAD TEST uS and note the timing reading on the LCD. 2. The acceptable range is 11.3-15.9uS with a stable reading. 3. A reading that is stable but outside this range indicates a defective timing component. a) A reading that is greater than 15.9uS is likely caused by an open yoke or yoke series capacitor. b) A reading that is less than 11.3uS is likely caused by defective retrace timing capacitors, IHVT, or excessive loading on the secondaries. Note: A few chassis manufactured by NAP may normally return timing readings slightly less than 11.3uS. 4. A reading that is fluctuating indicates that the flyback pulse waveshape contains ringing or multiple pulses. This is likely due to a defective flyback, excessive loading on the secondaries, or leakage.

Note: A few chassis may return a reading that fluctuates from normal to 0.1-0.5uS. This is due to the different impedance in the leads and circuit, not a defect in the set. 5. A reading of dashes (- - -) indicates improper lead hook-up or an open in the circuit. Be sure the pulse time is within the acceptable range before proceeding. II.Horizontal Output Dynamic Tests The three sections of the TVA92s Horizontal Output Dynamic Tests provide a quick and easy B+ voltage measurement, input drive test, horizontal output waveform analysis, and horizontal output device substitution. A. Dynamic B+ and Input Drive Measurements The first Dynamic Test enables you to check the regulated B+ supplied to the horizontal output stage and the input drive to the base of the H.O.T. 1. Remove the H.O.T. from the chassis and connect the Dynamic Test Leads

TEST: mA S

NORMAL RANGE 5-80 mA 11.3 15.9 S

BAD RANGE 80 mA 15.9 S

flash ON. If it reads ON, or will momentarily when the set is powering up, a drive signal is present. If it reads OFF there is a defect previous to the base of the H.O.T. This defect does not necessarily need to be repaired before continuing. B. Dynamic H.O.T. Sub & Drive These next steps allow you to substitute for the H.O.T. and operate the TV at full voltage without risking an expensive replacement H.O.T. 1. Set the HORIZ OUTPUT TESTS selector to DEVICE SUB CURRENT. 2. Turn the HORIZ OUTPUT DEVICE SUB & DRIVE slightly on until the SUB ON LED lights and watch the current reading on the LCD. If the current exceeds 500mA, turn the HORIZ DEVICE SUB & DRIVE off. There is likely a defect in the circuit that needs to be repaired before continuing. If the current stays below 500mA turn the knob quickly to the 12 or 1 oclock position (higher for larger sets). Adjust the HORIZ OUTPUT DEVICE SUB & DRIVE control to get normal horizontal deflection without foldover in the center of the CRT display. The current reading may now be over 1A depending on the size of the set. 3. With the HORIZ OUTPUT TESTS selector, check the DCV to see that the power supply is regulating and the PULSE PPV and PULSE TIME uS to measure the amplitude and width of the horizontal output pulse to be sure that the horizontal output stage is operating properly. Repair any problems before continuing. C.Dynamic Horizontal Output Parameter Measurements This final step monitors the horizontal circuits operation at full voltage so you can be sure that it is working properly with the H.O.T. installed. 1. Install a good H.O.T. and reconnect the Dynamic Tests leads as described above. Note: Be sure the HORIZ OUTPUT DEVICE SUB & DRIVE knob is in the OFF position. 2. Apply AC power to the chassis. 3. With the HORIZ OUTPUT TESTS selector, check DCV, PULSE PPV, and PULSE TIME uS for correct values.

Table 1: HORIZ OUTPUT LOAD TESTS Good/Bad ranges.

HORIZ LOAD TEST READOUTS mA S -------

MOST LIKELY CAUSES Improper Connections Open Flyback Open Output Stage Circuit Paths

BAD

----

Severe B+ Supply Short Or Leakage Path < 5 mA = Open Flyback Or Circuit Path Open Flyback Improper Collector Connection Open Ringer/Load Fuse No Severe Loading Or Timing Defects Severe B+ Leakage And/Or Flyback Secondary Short Or Leakage Path Flyback Transformer Defective Output Timing Components Flyback Transformer Severe Flyback Secondary Short Or Leakage Path Severe B+ Leakage Flyback Secondary Short Or Leakage Path Flyback Transformer Defective Output Timing Components

GOOD ----

GOOD GOOD BAD GOOD

GOOD BAD

BAD

BAD

NOTE: Fluctuating S readout values indicate abnormal flyback pulse ringing or timing.

Table 2: Possible HORIZ OUTPUT LOAD TEST readings and likely causes.

as follows: red to the collector connection, blue to the base connection, and black to the emitter connection or circuit ground. Note: A few chassis do not connect the H.O.T. emitter to ground. In this case, connect the black clip-lead to circuit ground, not the emitter connection. 2. Set the HORIZ OUTPUT TESTS selector to DCV, apply AC power to the chassis, and note the voltage reading on the LCD. This reading should closely match the schematics value for regulated B+. If the reading does not stabilize to this value, turn the HORIZ OUTPUT DEVICE SUB &

DRIVE on just enough so the SUB ON LED lights. This will provide feedback to the power supply if necessary. The DCV reading should be near the schematics value. If it is not, the power supply is malfunctioning and should be repaired before continuing. Turn the DEVICE SUB & DRIVE off before continuing. 3. Set the HORIZ OUTPUT TEST selector to INPUT DRIVE, apply power to the chassis, and note the reading on the LCD. The LCD should read ON. Some chassis horizontal circuits run off of a scan derived supply. With these types of sets you need to turn the TV off and back on again watching the LCD to see if it will momentarily

TVA92HORIZ OUTPUT TESTSHORIZ OUTPUT TESTSRINGER TESTS YOKE & FLYBACK SWITCHING XFORMER DYNAMIC TESTS DCV PULSE PPV PULSE TIME uS INPUT DRIVE

1300

RINGS mAuS KVPP

HORIZ OUTPUT LOAD TEST

uS

mA

TV OFF

TV ON

DEVICE SUB CURRENT

VERTICAL YOKE DRIVE LEVEL

HORIZ OUTPUT DEVICE SUB & DRIVE(CURRENT LEVEL)

0

SUB ON

OVERLOAD

-

+

OFF

1.5A MAX

OFF: TVS HORIZ OUTPUT ACTIVE ON: TVS HORIZ OUTPUT SUBISTITUTED

VERTICAL YOKE DRIVE OUTPUT50V 1A

RINGER/LOAD TESTS

DYNAMIC TESTS1500V MAX

!DISCONNECT YOKE FROM CHASSIS

FLOATING GROUND 1000V ISO

Fig. 3: Connections to perform the HORIZ OUTPUT DYNAMIC TESTS.

SYMPTOMB+ = 0 Volts Low B+ Volts

PROBABLE CAUSES Open Fuses Bad B+ Supply Shorted B+ Path B+ Power Supply Regulation Low AC Voltage B+ Power Supply Regulation Open Loads On B+ Supply No B+ No Input Drive Open HOT Open Flyback Primary Leaky Retrace Capacitor or HOT Flyback Loading Reduced Value Of Yoke Capacitor Bad Yoke Low B+ Insufficient Input Drive Retrace Capacitors Flyback Shorted Turn High B+ (regulator) No B+ No Input Drive Open HOT Open Flyback Primary Flyback Loading Flyback Shorted Turn Retrace Capacitors Yoke Yoke Series Capacitor Flyback Loading Flyback Shorted Turn Leaky HOT Damper Diode, Yoke, Retrace Capacitors, Yoke Or Yoke Capacitor Drive present to base of HOT No Drive To Base Of HOT

High B+ Volts Pulse PPV = 0 V Low Pulse PPV

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High Pulse PPV Pulse Time = 0 S Pulse Time < 11.3 S Pulse Time >15.9 S Multiple Pulse Times

Input Drive ON Input Drive OFF HOT = Horizontal Output Transistor

For More Information, Call Toll Free 1-800-SENCORE (736-2673)3200 Sencore Drive, Sioux Falls, SD 57107 1-605-339-0100 www.sencore.comForm #6905 Printed In U.S.A.

ig. 4: Possible HORIZ OUTPUT DYNAMIC TEST indications and their possible causes.

S

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Understanding The LC103s In-Circuit Capacitor TestCapacitors continue to be found in electronic circuits in record breaking numbers. In fact, the number of capacitors used in the manufacturing of electronic circuits continues to rise each year. In 1997, U.S. factories sold over 50 billion capacitors. As these capacitors age or are stressed by circuit voltages and heat many will fail causing improper circuit operation. Finding a bad capacitor and replacing it to restore normal circuit operation is challenging. First, you must identify which capacitor is suspect. Second, the capacitor must be unsoldered, removed, tested and reinstalled if good or replaced. These steps can be time consuming and you also risk damage to the circuit board traces or the capacitor. In fact, many manufacturers suggest replacement of surface mount capacitors when unsoldered and removed. Time and money is wasted if the removed capacitor is good or a replacement doesnt fix the problem. The Sencore LC103 ReZolver provides a patent pending test of capacitors while still soldered in-circuit. The in-circuit capacitor analyzing test determines if the capacitor is good, bad, or if it should be removed for further tests. This Tech Tip covers how to test capacitors in-circuitCOMPONENT TESTSIN-CIRCUIT OUT-OF-CIRCUIT

with the LC103s In-Circuit Capacitor Good/Bad test and explains how to interpret the test results.

looking at the test instrument could easily cause you to slip off the capacitor resulting in improper measurements, frustration and potential circuit damage. Sencore has overcome these mechanical difficulties with the innovative Adjustable In-Circuit Test Probe. The Adjustable In-Circuit Test Probe (AP291) joins two probe tips and provides an adjustable spacing wheel. The probe mechanically adjusts providing the versatility to fit the lead spacing of capacitors ranging from surface mount to large electrolytics. The angled tips provide ease in probing surface mount electrolytic capacitors. A push button switch conveniently located on the test probe enables the LC103s in-circuit capacitor test to avoid probe slippage. For most applications, the probe can be adjusted and connected to the in-circuit capacitor with one hand. In addition, the LC103 beeps when the first complete measurement is complete and the readings are momentarily frozen on the LC103 display after the test button is released to be sure you have sufficient time to view the in-circuit test result.

In-Circuit Capacitor Testing ChallengesObtaining meaningful and reliable test results when analyzing a capacitor in-circuit has many complications. First you must make an electrical connection to each of the capacitors test leads and maintain a stable connection while performing the tests. Second, you must perform analyzing tests that determine with a high reliability if the capacitor is good or if it may have a defect and should be removed for further testing. You also need the flexibility to test a wide range of capacitors found in todays circuits to be comprehensive. Finally, you need a simplified solution to interpreting the in-circuit capacitor test readouts to avoid confusion. The first challenge is simply making connection to an in-circuit capacitor. Electrical connections to each of the capacitors leads while soldered in-circuit is complicated by a wide range of capacitor types, values, sizes and mechanical lead basings. Since most capacitors do not expose enough lead length for clip lead connections when soldered in-circuit, connections must be made on the solder side of the circuit board. Surface mount capacitors are already mounted directly to the solder side. Connection to the soldered side of the circuit board requires 2 sharp probe tips. Connecting to each of the capacitor legs requires a hand for each probe, leaving no hands to operate a test instrument. Even if you were able to hold each probe with one hand, reaching or

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CAPACITOR GOOD/BAD

CAPACITOR VALUE

CAPACITOR ESR

S

DIELECTRIC ABSORPTION INDUCTOR GOOD/BAD

CAPACITOR LEAKAGE

INDUCTOR VALUE

INDUCTOR RINGER

Fig. 1: The Sencore LC103 ReZolver provides a patent pending in-circuit capacitor test to reduce servicing time and expense.

Fig. 2: A push button switch conveniently located on the test probe enables the LC103s in-circuit capacitor test.

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While capacitors fail in several ways a combination of two common measurements, capacitor value and equivalent series resistance (ESR), can determine if a capacitor is likely good or suspect in-circuit with a high level of reliability. Aluminum Electrolytic capacitors and tantalum capacitors commonly fail from increased ESR prior to changing value and increasing in leakage. Other capacitor types commonly change value. Testing both value and ESR provides the most comprehensive and accurate in-circuit test results. An ESR tester alone would mistakenly report a shorted capacitor or circuit short as good. Likewise, a capacitor value test alone would miss capacitors with excessive ESR. Accurate in-circuit capacitor testing can be hindered by the presence of components in parallel with the capacitor. Capacitance, resistance, inductance and semiconductor junctions in parallel with the capacitor may influence the accuracy and reliability of in-circuit capacitor tests. At times the parallel components may have little effect on the accuracy of the tests but at other times the parallel components cause significant changes to the test results. It is important to know when the parallel components are effecting the in-circuit capacitor measurements.

The LC103s In-Circuit Capacitor test performs several sophisticated tests to determine if parallel components are present which may be effecting the accuracy of the in-circuit capacitance value and ESR measurements. The tests include a test to determine how much current is needed to hold a capacitor charge. Current exceeding the original charging current by 20% indicates parallel resistance that can impact the capacitor value test. A second test uses a selection of test frequencies and analyzes the Xc of the circuit. A capacitance value is determined and compared to a capacitance value determined with an RC time constant value measurement. Large differences in the capacitance values indicate parallel components which would impact the in-circuit measurement accuracy.

rating. A calculator would be needed to determine if the measured capacitance value is within a normal tolerance. The LC103 provides Good/Bad test analysis with every in-circuit capacitor test to help determine if the capacitor value and ESR is within a normal range. ESR evaluations are based upon maximum allowable limits established by component manufacturers and the Electronic Industries Association (EIA). Capacitor measured values are automatically compared to maximum and minimum values calculated from the entered value and tolerance of the capacitor being tested.

LC103 In-Circuit Capacitor TestingThe LC103 offers two alternatives for Good/Bad testing a capacitor with the InCircuit Capacitor Good/Bad Test function. You may perform a basic Good/Bad test of the capacitor or a complete EIA Good/Bad test. Both testing alternatives perform the same analyzing tests but use different references for Good/Bad interpretation. The display readouts vary slightly depending upon the test alternative.

The LC103s In-Circuit Capacitor test function measures the capacitance value It can be difficult to determine if a and ESR of an in-circuit capacitor. These capacitor ESR readout is normal or not measurements are simultaneously as capacitor ESR values vary among displayed in the COMPONENT TEST different capacitor types and also vary RESULTS display. Capacitance value with the capacitors value and voltage measurements range from 0.002 uF to 20,000 uF. Capacitor ESR measurements are In-Circuit Capacitor Test Component Parameters Good/Bad Judgement Factors displayed for capacitors ranging Basic Good/Bad Check None Measured capacity and 50V in value from 0.02 Tantalum ESR Chart if >1 F uF to 20,000 uF. Ceramic (10) if

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1 Analyzing The HV Circuits With The VA62A 2 Analyzing The Horizontal Output Pulse With The Waveform Analyzer 3 The TVA92s Horizontal Output Tests 4 Understanding the LC103s In-Circuit Capacitor Test 5 Understanding Horizontal Output Stages of Computer Monitors CONTENTS
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