--%>
Assignment Help - homework help

  Fourth 10 Faults By Observing Symptoms

Introduction to Fourth 10 Faults By Observing Symptoms:

1. Poor Contrast or Dim Picture; But There Is Sufficient Brightness

A. Defective video amplifier transistor, the biasing components and contrast control of it.

B. Misaligned VIF stage

C. Dry soldering; copper print cut.

2. Dim Picture; Insufficient Brightness

The picture tube is Defective.

3. Out Of Focus Or Defocus

A. Low/ high voltage at G3

B. CRT is Defective

4. Arcing In Picture Tube

Very firstly, switch off the TV receiver. Cut off the power supply and test the voltage at the power supply output is whether high or not (accurate voltage: 20" B AV 11OV; 14" between 10.4V) at the output of power supply. Observe the reasons and it should be rectified first.

Yet after that arcing occurs, the picture tube is defective. Replace that defective picture tube with a good one.

5. Silvery Picture

If silver coating type picture displays on the high white levels of the picture, it is termed as silvery picture.

A. Weak picture tube

B. It may be decreased by the help of picture tube rejuvenator circuit.

C. Replacing the new one is the fixed resolution.

6. Smeared Picture

Very small lines emerged adjacent to the picture is termed as Smeared picture. It is because of excessive low frequency response.

A. Defective peaking coil

B. Misaligned VTF stage

7. Retrace Lines Only; Sound Ok

A. Defective video output transistor and the biasing components of it.

B. Excessive voltage to picture tube's G, and G2 (by using low value of supply resistors misappropriate)

C. Short circuited calliope and filament of the cathode of the picture tube (rare). If short circuit takes place, correct it with the help of short removal circuit.

8. Picture with Retrace Lines; Sound Ok

A.  Defective video output transistor and the biasing components of it

B. a little high voltage to Gl and G2

C. test blanking amplifier, the biasing components of it and track of the blanking pulses to the video amplifier.

D.  Weak picture tube, (rare)

8 A) Switch off Spot

Even after the TV receiver is being switched off A bright spot emerges is termed as switch off spot. If it perseveres for a long time, the phosphor bums and the result a black spot emerges in the centre of the screen permanently.

A.  Open capacitor earthed from G1

B.  Open spot killer diode.

C.  Loose contact in CRT base.

9) Snow Only; Noise Only (Picture and Sound Have Not Been Received)

For the above said symptoms, follow the instructions that provided below to trouble shoot the defects. Very firstly, test the TV receiver in a neighbour's house (if it is feasible), where reception should be fine.

At that time, the picture and sound is very good,

Fault is in the antenna system and related devices of it.

A. Incorrect antenna direction

B. Test the dipole connection, continuity of feeder wire and balun transformer.

C. Defective Booster and the power supply of it.

If picture and sound are not received properly.

Fault is in the TV receiver.

D.  Disconnected input wires to the tuner.

E. Test the B+ and AGC voltages to the tuner.

F. Not proper adjustment of AGC preset.

G. Defective RF tuner.

H. Misaligned VIF stage.

I. Dry soldering; copper track cut

J. If IC is employed in the VEF stage, calculate pin voltages.

K. If needed, finally replace the IC

10. Mismatching of Audio and Video

Yet after fine tuning is completed, the sound is received completely when the picture is not clear, and conversely, this type of effect is termed as Mismatching of audio and video.

A. Test the antenna, Booster and feeder wire

B. Not proper alignment of AGC preset.

C. Defective tuner.

10 A) Only Few Channels Received

Defective tuner

Latest technology based Electrical Engineering Online Tutoring Assistance

Tutors, at the www.tutorsglobe.com, take pledge to provide full satisfaction and assurance in Fourth 10 Faults By Observing Symptoms homework help via online tutoring. Students are getting 100% satisfaction by online tutors across the globe. Here you can get homework help for Fourth 10 Faults By Observing Symptoms, project ideas and tutorials. We provide email based Fourth 10 Faults By Observing Symptoms homework help. You can join us to ask queries 24x7 with live, experienced and qualified online tutors specialized in Fourth 10 Faults By Observing Symptoms. Through Online Tutoring, you would be able to complete your homework or assignments at your home. Tutors at the TutorsGlobe are committed to provide the best quality online tutoring assistance for Electrical Engineering homework help and assignment help services. They use their experience, as they have solved thousands of the Electrical Engineering assignments, which may help you to solve your complex issues of Fourth 10 Faults By Observing Symptoms. TutorsGlobe assure for the best quality compliance to your homework. Compromise with quality is not in our dictionary. If we feel that we are not able to provide the homework help as per the deadline or given instruction by the student, we refund the money of the student without any delay.