Question about Televison & Video

1 Answer

Have some red shadowing in picture - Televison & Video

Posted by on

  • jagu366 Apr 14, 2008

    I have the same problem. somebody told me that it was the conversion amps. Have no idea what they are.



1 Answer

  • Level 3:

    An expert who has achieved level 3 by getting 1000 points


    An expert that got 10 achievements.


    An expert that got 5 achievements.


    An expert who has answered 1,000 questions.

  • Televison & ... Master
  • 1,689 Answers

Without seeing the set and checking it out, this is hard to accurately tell.

The following is when a single CRT or tube in a projection TV set starts to get weak. It is the same for a CRT when any one of its electron-guns starts to go weaker than the others.

On any CRT based set either with a single CRT or with seperate projection CRT's, as the tube(s) (CRT's) get weak their emission goes down. One of the symptoms is that the beam focus gets softer.

When a CRT goes weak the beam current will decrease. This lowers the mass or intensity of the electron beam. This makes the beam width wider, and thus the image focus is softer. Having a wider beam in a single CRT or single colour section of a CRT's electron gun also means that there will be more beam width overlap in comparison to the other CRT's or the other electron-guns in the case of a single CRT. This will give the appearance of an overlap or edging especialy with sharp or thin lines.

There is also a symptom where the convergence can get less accurate as the convergence control circuits age. This means that the scan tracking between each of the CRT's or the electron-guns in a single CRT start to not be able to accurately keep converged to each other. This will produce a border effect between the beam position accross the scanning of the screen.

Sometimes with a projection CRT set if there are separate focus controls in the high voltage (HV) section for each of the colours the beam focus may be able to be cheated if the CRT is not too weak. In most CRT sets the focus voltage is shared between all the colour channels, and thus there is no possiblity to control each channel individualy.

With weak CRT's there are other factors that come in to effect. One big one is that the colour tracking gets impossible to be accurate. This is because the gain liniarity of the tube becomes out of spec. As each of the CRT's or the electron-guns in a single tube become weak they will lose their tracking accuracy in relation to each other. In the design of the drive circuits of the better TV sets there are some auto circuits to try to make sure that the tracking is stable. But, when the electron-guns become too weak the circuits run out of range.

Jerry G.

Posted on Apr 14, 2008


1 Suggested Answer

  • 2 Answers

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

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.
Good luck!

Posted on Jan 02, 2017


Add Your Answer

Uploading: 0%


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



Related Questions:

1 Answer

My hitachi big screen has red shadows on picture how do i fix it

What you described sounds like a convergence problem. When convergence has failed the colors will commonly look 3D,warped, etc. This tips page here on Fixya has more details.

Jan 27, 2013 | Hitachi 43FWX20B 43" Rear Projection...

1 Answer

Picture has a red shadow. especially

Convergence problem on rear projection CRT TVs.

Apr 19, 2010 | Televison & Video

1 Answer

Blue and red shadows on the TV picture

open up the TV then clean up the silver screen and the 3 light bulbs inside its probably just dirty.

Oct 05, 2009 | Philips Magnavox 51MP392H Rear Projection...

1 Answer

Picture is bowing & has red & green shadows

what type of tv do you have. sounds like a loss of covergence. if its

May 04, 2009 | Televison & Video

1 Answer

Red colour shadow in the picture


this means you need to replace the resistor or you need to replace the convergence correction amplifier IC...


Jan 15, 2009 | Mitsubishi VS-45607 45" Rear Projection...

1 Answer

Maganvox TV with red-shadow to picture

Hi Emily,

Your TV has bad convergence amplifiers. They are large integrated circuits that are mounted on large metal heat sinks. They have a part number on them, but might be covered up by a bracket. The part number should start with STK. They are replaced as pairs. You will have to find someone with the skills necessary to replace them.

Best Regards,


Feb 10, 2008 | Philips Magnavox 51MP392H Rear Projection...

1 Answer

Red Shadow on Picture

convergence ic bad

Jan 14, 2008 | Toshiba 61H71 61" Rear Projection...

1 Answer

Convergence problem

does it cast red shadows on the picuture.. red shadows around letters. might be the red convergence or could be the read yoke has come loose

Jan 02, 2008 | Panasonic PT-47WX49 47" Rear Projection...

1 Answer

Red shadows in picture

Possible "blooming"==red CRT, adjust screen control==qualified tech only.

Oct 09, 2007 | RCA D52W19 52" Rear Projection Television

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

Related Topics:

473 people viewed this question

Ask a Question

Usually answered in minutes!

Top Televison & Video Experts

The Knight
The Knight

Level 3 Expert

75025 Answers

Donald DCruz
Donald DCruz

Level 3 Expert

17130 Answers

Cindy Wells

Level 3 Expert

5302 Answers

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

Answer questions

Manuals & User Guides