JVC AV-29MXP6/V, AV-25MXP6/V, AV-21MXP6/V service manual Troubleshooting

Page 113

Troubleshooting

If a problem occurs when you are using the TV, check the below troubleshooting guide before calling for repair.

• No picture, no sound

Deactivate the BLUE BACK function if it is turned on.

 

• Choose the appropriate sound system. Refer to

 

“SOUND SYSTEM” on page 13.

• Snowy picture

Check the aerial cable and its connection with the TV.

 

 

• Stripes appear on the

• Interference occurs caused by other devices such as

picture

an amplifier, personal computer, or a hair drier. Move

 

such devices away from your TV.

Double-pictures

• Interference occurs caused by signal reflecting

(ghosting) occur

from mountains or building. Try to adjust the aerial’s

 

direction or use a better directionality antenna.

• Poor picture

• Choose the appropriate colour system. Refer to

 

“COLOUR SYSTEM” on page 9.

 

• Adjust the COLOUR or BRIGHT setting. Refer to

 

“PICTURE SETTING” on page 10.

• White and bright still

• Inevitable phenomenon due to the nature of the picture

image look as if it

tube. This is not a malfunction.

were coloured

 

• Top of the image from

• This is due to the condition of the video signal whereby

software products or

the image was not recorded properly. This is not a

video tape is distorted

malfunction.

• Poor sound

• Choose the appropriate sound system. Refer to

 

“SOUND SYSTEM” on page 13.

• Stereo or bilingual

• TV channel reception is poor. Change the stereo/

sound is unclear

bilingual mode to mono sound (see page 16).

• Cannot operate the

• The batteries may be exhausted. Replace with new

remote control

batteries (see page 7).

 

• Ensure that you are operating the remote control at

 

less than seven meters from the front of your TV.

• Cannot operate the

• Press TV/VIDEO button to return to TV mode and try

menus

operating the menus.

• Cannot operate the

• Deactivate the CHILD LOCK function if it is turned on

front control buttons

(see page 16).

 

 

• Colour patches appear

• This may due to the magnetized device such as a

at the corner of the

speaker near to your TV. Keep the device apart from

screen

your TV. Alternately, you can also use the magnetic-

 

shielded speaker.

 

 

• Picture is tilted

• This may due to the earth magnetism. Refer to

 

“PICTURE TILT” on page 11 to correct the tilt.

 

 

• Image takes a short

• Image required time to stabilize before display. This

period to be displayed

is not a malfunction.

 

 

• TV may emit crackling

• This is due to a sudden change in temperature

sound

and it is not a malfunction. If the crackling sound

 

is too frequent, request your service technician for

 

inspection.

 

 

• Feel a slight electric

• This is due to the static electricity of the picture tube

shock when touching

and it will not harm the human body. This is not a

the TV screen

malfunction.

 

 

• The Auto Signal

• Please check that the AUTO SIGNAL DETECT

Detect function does

function is on or off.

not work

• Turn the VCR or DVD player off, wait a while, then

 

turn it on again.

 

• Inspect the video cable connection on VIDEO-2 that

 

they are connected properly.

 

 

• Suddenly, a channel

• Some VCRs and DVD players can trigger Auto Signal

or input was

Detect even after you choose a different input.

changed to VIDEO-2

• Please turn off the AUTO SIGNAL DETECT

inputs.

function.

 

 

• “PLEASE

• Please disconnect either S-VIDEO cable or video input

DISCONNECT

cable from Video-1 input.

VIDEO-1 CABLE!”

 

appears on the

 

screen.

 

22

Image 113
Contents AV-29MXP6/V AV-21MXP6/V AV-25MXP6/V AV-29MXP6/V Items ContentsLeakage Current Check Safety PrecautionsAlternate Check Method No.YA4761-3Auto Signal Detect Features DVD Picture ModePicture Mode Cinema SurroundNo.YA4761-5 Techninal Information Main MI-COM CPU PIN FunctionWire Clamping and Cable Tying Disassembly Procedure AV-21MXP6/V Removing the Rear CoverRemoving the Main PW Board Removing the SpeakerNo.YA4761-7 AV-21MXP6/XDisassembly Procedure AV-25MXP6/V Removing the Rear Cover No.YA4761-9 AV-25MXP6/VRemoving the Chassis Chassis Base and Control Base Disassembly Procedure AV-29MXP6/V Removing the Rear CoverRemoving the AV Terminal Board Remove the Rear Cover Remove the 4 screws C as shownNo.YA4761-11 Front SideMenu Memory IC ReplacementSettings of Factory Shipment Button Operation System Constant SettingRemote Control Direct Operation Remote Control Menu Operation Picture SettingInstall Setting Feature SettingService Mode Setting Items VSM PresetHow to install Chip parts Resistors, capacitors, etc Replacement of Chip ComponentSoldering Iron Transistors, diodes, variable resistors, etcPreset Setting Before Adjustment Adjustment PreparationAdjustment Items „ Check Items „ VSM Preset SettingNo.YA4761-17 Adjustment Location AV-21MXP6/V, AV-25MXP6/VFront 18 No.YA476 Adjustment Location AV-29MXP6/VMain PWB ASS’Y CRT Socket Setting Method Service Mode ItemsMemorize the Adjustment Data Release of Service Mode20 No.YA476 Service Mode Flow ChartPAL Secam NTSC3 NTSC4 Video Initial Setting Value of Service Mode32 ~ +31 No.YA4761-2122 No.YA476 No.YA4761-23 Mode AV-21MXP6/V Function100Hz 300Hz 1kHz 3kHz 8kHz AV-25MXP6/V Function+12 AV-29MXP6/V Function+11 No.YA4761-2543 50Hz Others 60Hz CompressS.CR 32 ~ +31 LIN 32 ~ +3150Hz 60Hz 43 50HzCool Warm Normal Theater Bright SoftTheater Measuring Test point Adjustment part Description Instrument Adjustment Procedure Check ItemB1 Voltage High Voltage HV voltmeterTuner / if Circuit Delay PointAGC FocusPAL V. Position PositionNtsc V. Position SizeNtsc H. Size PAL H. SizeSide PIN PAL Side PINPAL V. Linearity LinearityNtsc V. Linearity Corner PINNtsc H. BOW BOWPAL H. BOW PAL Trapezium PIN Follow the same to 7 as in PAL Side PINNtsc Trapezium PIN Select 8. COR-UPVideo Circuit „ Video 2 SET ComponentWhite Composite White BalanceSUB SUB BrightContrast SUB ColourPAL Tint SUB TintNtsc 3.58 Tint Ntsc 4.43 TintSTANDARD, Soft and Theater VSM Preset Setting1. R Drive to 3. B Drive to the values Warm and NormalPurity and Convergence „ Purity Adjustment No.YA4761-41 „ Static Convergence Adjustment„ Dynamic Convergence Adjustment Self Check Functions Outline Indication by the Power LEDSelf Check Items Self Check Indicating FunctionVPT Copyright 2006 Victor Company of Japan, Limited Schematic DiagramsIndication of Parts Symbol Example SafetyIndications on the Circuit Diagram Specified Voltage and Waveform ValuesAV-21MXP6/V, AV-25MXP6/V AV-29MXP6/V ContentsMain PWB Pattern 2No.YA476No.YA4762-32-4No.YA476 Main PWBFront Control PWB1/2 No.YA4762-72-8No.YA476 Main PWB Circuit Diagram AV-21MXP6/V 1/4 2/4 SHEET1No.YA4762-92-10No.YA476 Main PWB Circuit Diagram AV-21MXP6/V 3/44/4 SHEET2No.YA4762-112-12No.YA476 Main PWB Circuit Diagram AV-25MXP6/V 1/4 2/4 SheetNo.YA4762-132-14No.YA476 Main PWB Circuit Diagram AV-25MXP6/V 3/44/4 SHEET4No.YA4762-152-16No.YA476 Main PWB Circuit Diagram AV-29MXP6/V 1/2 SheetNo.YA4762-172-18No.YA476 Main PWB Circuit Diagram AV-29MXP6/V 2/2 SheetNo.YA4762-192-20No.YA476 CRT Socket PWB Circuit Diagram AV-29MXP6/V SheetNo.YA4762-212-22No.YA476 Front Control PWB Circuit Diagram AV-29MXP6/V SheetNo.YA4762-232-24No.YA476 Bass PWB Circuit Diagram SheetNo.YA4762-25 26No.YA476 FrontNo.YA4762-272-28No.YA476 Main PWB Pattern AV-29MXP6/VBass PWB Pattern Solder Side CRT Socket PWB Pattern AV-29MXP6/VBass PWB Pattern Parts Side No.YA4762-292-30No.YA476No.YA4762-312-32No.YA476 Front Control PWB Pattern AV-29MXP6/VNo.YA4762-332-34No.YA476 Voltage Charts AV-21MXP6/V, AV-25MXP6/VNo.YA4762-35 Waveforms AV-21MXP6/V, AV-25MXP6/VMain PWB 36No.YA476No.YA476 No.YA4763-1 Parts ListContents No.YA4763-3 Using P.W. Board & Remote Control Unit4No.YA476 100 V01 L01 101 102106 103 105 104 T522 No.YA4763-5 Printed Wiring Board Parts List6No.YA476 No.YA4763-7 8No.YA476 No.YA4763-9 10No.YA476 487 5No.YA4763-11 12No.YA476 V01 L01 100 101 102 106 103 105 104No.YA4763-13 Main P.W. Board Assy SCW-1646A-H214No.YA476 No.YA4763-15 16No.YA476 No.YA4763-17 B Assy AV-29MXP6/V 18No.YA476No.YA4763-19 V01 L01 100 101 103 DY01 2822 3018 102 40 T52220No.YA476 Main P.W. Board Assy SCW-1647A-H2No.YA4763-21 22No.YA476 No.YA4763-23 24No.YA476 CRT Socket P.W. Board Assy SCW-3037A-H2No.YA4763-25 Bass P.W. Board Assy SCW-6003A-H2Packing Packing Parts List Colour Television Do not allow objects or liquid into the cabinet openings Main features Knowing your TV’s featuresNo. Press Remote control buttons and basic functionsRemote control buttons and basic functions Front of the TV TV buttons and functionsTurn off the equipment including the TV before connecting Setting up your TVSetting up your TV Colour System Basic setting for picturePicture Mode Picture Booster Picture Setting White BalanceAI ECO Sensor ECO/ECO Mode Advanced setting for pictureCompress Blue BackPIP Original features for pictureSound Mode Basic setting for soundSound System BalanceAI Volume Advanced setting for soundCinema Surround EqualizerDVD Picture Mode Auto Signal DetectDVD Sound Mode DVD MenuCustomized setting Beep VIDEO-2 Setting DisplayAuto Program TV channel presettingDelete TV channel presetting CH/CC number Additional preparation Before connectingTroubleshooting AV-25MXP6 SpecificationsModel AV-29B316 AV-29M316 AV-29S356 AV-29B316BK

AV-29MXP6/V, AV-21MXP6/V, AV-25MXP6/V specifications

The JVC AV-25MXP6/V, AV-21MXP6/V, and AV-29MXP6/V are a trio of high-performance CRT televisions that represent a combination of cutting-edge technology and practical design, catering to the diverse needs of home entertainment enthusiasts. These models are characterized by their impressive picture quality, robust build, and user-friendly features, making them a prominent choice during their production era.

One of the key features of these models is their screen sizes, which cater to different room sizes and viewing preferences. The AV-25MXP6/V offers a compact 25-inch display, ideal for smaller living spaces or bedrooms, while the AV-21MXP6/V with its 21-inch screen is perfect for desk setups or as a secondary television. The AV-29MXP6/V, on the other hand, boasts a larger 29-inch display, making it suitable for home theaters or larger family rooms.

JVC is renowned for its superior picture technology, and these models are no exception. They utilize a high-quality CRT screen that provides deep contrast, vivid colors, and sharp details. The picture performance is further enhanced by JVC's proprietary circuitry, including a dynamic contrast system that adjusts brightness and contrast levels based on the content being displayed, resulting in a more immersive viewing experience.

Moreover, these televisions come equipped with several input options, including RF, composite, and S-video inputs, allowing users to connect multiple external devices such as DVD players, game consoles, and VCRs. With built-in tuners, viewers can easily access over-the-air broadcasting, making these models versatile entertainment hubs.

Another noteworthy characteristic is the user-friendly interface that JVC has engineered into the AV-25MXP6/V, AV-21MXP6/V, and AV-29MXP6/V models. The on-screen menu provides quick access to settings and customization options, allowing users to tailor the viewing experience to their preferences, including the ability to adjust color tones and picture settings.

In addition to their functionality, these televisions also sport an elegant design that incorporates a sleek frame and aesthetically pleasing finish, making them a suitable complement to any home décor.

Overall, the JVC AV-25MXP6/V, AV-21MXP6/V, and AV-29MXP6/V models represent a harmonious blend of technology, style, and user-centric features, making them reliable choices for anyone seeking quality CRT televisions for their home entertainment needs. Though newer technologies have since emerged, these models remain a fond memory for many who experienced their remarkable performance.