Question about Televison & Video

2 Answers

How do I fix no display on screen?

I have a china t.v that has no display on screen. flyback cap oscilate and there is no horizontal or vertical issu. 180 voltage on base and heater 5 voltage is ok... picture tube is ok what should I do plz help me fixya team..

Posted by on

2 Answers

  • Level 3:

    An expert who has achieved level 3 by getting 1000 points

    Top Expert:

    An expert who has finished #1 on the weekly Top 10 Fixya Experts Leaderboard.

    Superstar:

    An expert that got 20 achievements.

    All-Star:

    An expert that got 10 achievements.

  • Televison & ... Master
  • 73,740 Answers

Check whether the heater filament inside the CRT glow or not.
Electro help

Posted on Apr 04, 2015

  • Level 2:

    An expert who has achieved level 2 by getting 100 points

    MVP:

    An expert that got 5 achievements.

    Novelist:

    An expert who has written 50 answers of more than 400 characters.

    Scholar:

    An expert who has written 20 answers of more than 400 characters.

  • Expert
  • 99 Answers

OK I will try a little bit, If we are talking about a glass tube TV then No picture can be a number of things, first is there a tube heater glowing? have we got EHT and Focus (static when tube front touched or crackle on turn on) next thing is are its colour guns Off by some means (blanking circuit).
This will occur in response to a fault mostly, in the main Frame or Field collapse which causes a line mid screen, this will damage a tube so a sets reaction is to clamp off the guns (no picture).
If I determined EHT and Focus volts existed (if not suspect flyback transfomer) my next move would be to naughty and flash the tube with a resistor, A resistor of about 56K or little higher and a wire at one end long enough to reach from its earth to the tube base, with the set on JUST DAB QUICKLY one of that tubes cathodes while looking at its screen via a mirror. Please note this is non technical way but all you need to know is, is there just a line or a single colour screen (yes I know you tech guys but it is a quick way).
If it is a line then you have frame collapse and thats where to look, if its blank then there is a lack of video drive, possibly a IC or in some old sets I worked on their output emitters sat raised via a simple zener of about 7.5v which goes o/c and its tube guns lift to a high voltage then cut off if I remember rightly cathodes would be around 140 to 165v depending on tube size etc but do not quote me.
Now a thought occurs to me has this flyback transformer got control pots on it, one for focus (top one) and a second for G2 (a high voltage for the tube) note its position before you move it, if after flashing that tube you see a picture then this voltage is low (been got at or faulty transformer) if this transformer has three controls then I would get worried as this idea was employed on monitors to enhance their focus and presented an extra high voltage those I did see with tubes blown (internal flashover) because these transformers had failed.
This is enough to start with hope this helps.........

Posted on Apr 03, 2015

1 Suggested Answer

6ya6ya
  • 2 Answers

SOURCE: I have freestanding Series 8 dishwasher. Lately during the filling cycle water hammer is occurring. How can this be resolved

Hi,
a 6ya expert can help you resolve that issue over the phone in a minute or two.
best thing about this new service is that you are never placed on hold and get to talk to real repairmen in the US.
the service is completely free and covers almost anything you can think of (from cars to computers, handyman, and even drones).
click here to download the app (for users in the US for now) and get all the help you need.
goodluck!

Posted on Jan 02, 2017

Add Your Answer

Uploading: 0%

my-video-file.mp4

Complete. Click "Add" to insert your video. Add

×

Loading...
Loading...

Related Questions:

2 Answers

No picture, Horizontal line center of screen


Can be a case of vertical collapse. If this is the case, then the vertical oscillator and/or the vertical driver circuit are faulty. .

You can take you problem directly to zenith. They have a customer service post available here

Mar 30, 2008 | Zenith Z32H41D TV

1 Answer

How do I fix red vertical line?


If you wish to get some details; check the site linked here. Pull up older posts. Surf the site with patience. http://electronicshelponline.blogspot.com/

Mar 22, 2015 | LG Televison & Video

1 Answer

Where is horizontal output ic in my t.v?


There is no horizontal oscillator IC. The horizontal oscillation is generated and outputted by the main system control IC LA76810 itself. Refer some circuit diagrams using LA76810 to get more details about the horizontal oscillation output from the IC. Measure the frequency at that output pin. It should be some ever near 15.62KHz.
If you wish to get some details; check the site linked here. Pull up older posts. Surf the site with patience. http://electronicshelponline.blogspot.com/
Type in the IC number, in the search box [at the top right] of the display window, and press enter to get all related posts. It will make surf easy.

Jan 31, 2015 | Televison & Video

1 Answer

My crt acer ac512 monitar only centre line view,c"not full view why?


there are several reasons why picture of crt monitors did not display good picture. if your monitor had horizontal line at the center of the screen?...the faulty is in the vertical deflection, check the vertical oscillator also the fusible resistors & capacitors around that section. if there had vertical line at the center of the screen?..check the horizontal deflection, horizontal output transistor also check the YOKE.

Jul 31, 2014 | Acer Computers & Internet

1 Answer

No vertical output, but vertical ic workng fine,vertical supply ok,


Touch the input pin of the vertical IC, by the blade of the screwdriver, and see whether there is a tendency to change with width of the horizontal line on screen. If so, check and replace the horizontal, video if, vertical oscillator jungle IC. Check the frequency to the input of the vertical scan IC, with a frequency meter. If there is frequency, and still no vertical scan output, check the yoke connection, and make sure that it has no open circuit. If you wish to get some details, http://electronicshelponline.blogspot.com/ Pull up older posts.

Dec 18, 2013 | Televison & Video

1 Answer

No horizondal oscilation.


no line flyback transformer
vertical line horizontal out put circuit
horizontal line vertical output circuit
at fault

Sep 14, 2009 | Televison & Video

1 Answer

Help me to fix the TV


Try to inspect for a loosed connection in the printed circuit board especially in the horizontal circuit. This includes the ic for horizontal oscillator, transistor for horizontal driver, horizontal output transistor and the high voltage section which includes the flyback. Pls. observe safety when dealing with these ciruits coz it deals with high voltage! Good luck!!

Apr 22, 2008 | RCA 27F650T 27" TV

3 Answers

Samsung 591s monitor


It isn't getting a steady, usable source of power, you can try to diagnose this your self but it will be a power issue INSIDE the monitor within the circuit board

Jan 22, 2008 | SAMTRON 55V 15" CRT Monitor

2 Answers

RE:Sanyo 27 " Flat Tube Set


What about a cap in the power supply for the vertical circuit? Usually found near flyback-- 2)check vertical drive signal (comes from jungle IC ).Use your scope....

Sep 26, 2007 | Sanyo DS27910 27" TV

Not finding what you are looking for?
Televison & Video Logo

Related Topics:

63 people viewed this question

Ask a Question

Usually answered in minutes!

Top Televison & Video Experts

The Knight
The Knight

Level 3 Expert

73698 Answers

Cindy Wells

Level 3 Expert

5062 Answers

Electro Med Services...
Electro Med Services...

Level 3 Expert

6694 Answers

Are you a Televison and Video Expert? Answer questions, earn points and help others

Answer questions

Manuals & User Guides

Loading...