Question about Sanyo DS31520 31" TV

1 Answer

Circuit board was damaged in electrical storm. Replaced with new board. Now, screen comes on full raster, but with retrace lines. Picture is very faded and barely visible behind lines. Sound is OK and all controls work OK. TV worked perfectly prior to storm. Also, can't find TV service manual. Sam's photofact 4963, any clues?

Posted by on

1 Answer

  • Level 1:

    An expert who has achieved level 1.


    An expert that got 5 achievements.

    New Friend:

    An expert that has 1 follower.


    An expert who has answered 20 questions.

  • Contributor
  • 76 Answers
Re: Circuit board was damaged in electrical...

I am unable to find in your statement about which brand or type of motherboard is used. One thing i come to know your using service mode kit. knowing in your statement your are a technical person. My simple idea is first you set the TV in standby mode using remote. Then in FBT reduce the screen control minimum position, the release standby. Now the tv is oscillated, now slightly increase screen control till get maximum video and zero retrace line set in position. Even no improvement give me clear picture of brand and microprocessor ic etc. there is a chances to solve by having the above details.

Posted on Sep 02, 2007

Add Your Answer

0 characters

Uploading: 0%


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


3 Points

Related Questions:

1 Answer

Black screen, sound ok.flyback lines when G2 turned up

Never tune G2 voltage too up to a state, to appear retrace lines on screen. it is bad. It might make the CRT damaged. Check the video output card, and the voltages comes to it. This card can be located at the neck of the picture tube itself, will directly plugged to its back of the neck. Reduce the G2 voltage, in such a way that, there is no retrace lines appear. Be careful. To get some details, Pull up older posts

Dec 12, 2013 | Standard (CRT) Televisions

1 Answer

Daewoo dtq-206sc have retrace lines

if retrace lines at top of picture the issue is in the vertical circuit--usually a bad filter cap and or the output chip (most of the caps that cause that are 220 uf or 330 uf and connected directly to one pin on the chip.

If retrace lines are across entire screen---likely the master screen control on the Flyback is set too high--causes excessive brightness and the retrace lines.

May 22, 2012 | Daewoo DTQ-20U6SC 20" TV

1 Answer


This is what we called RETRACE LINE. This happens when the 200 V at C board is missing. Some times a 4.7 Ohms fusible resistor open, and find out the reason why it opens, could be a damaged RGB drive. The worse if retrace line show up together with a saturated green picture your green gun is damaged, in this case you have to change your CRT. Good Luck

Feb 24, 2010 | JVC AV-36D202 36" TV

1 Answer


Picture goes to high green with retrace lines that shows picture tube is defective and requires replacement.
Usually in above symptom, TV goes to standby mode and standby light blinks when green raster problem occurred.
New TV is better option because picture tube of KV-34XBR960 would not be available any more.

Aug 14, 2009 | Sony Standard (CRT) Televisions

1 Answer

Have 46 samsung dlp that has green lines all over the screen . menu still works but doesnt go away on the menu mode. the green is so thick that you cant see any picture in the background.

Red, green, or blue retrace lines ( a quote from "Notes on the Troubleshooting and Repair of Television Sets", found at )

Where only one color is showing, suspect an incorrectly adjusted individual background/bias control or bad part on the CRT neck board for that color.
  • Individual brightness/background/bias control(s) - mark setting of pot for the problem color and then see if a slight adjustment removes the retrace lines. See the chapter: "TV Adjustments". Of course, if this happened suddenly, the problem is not due to a misadjusted control though a dirty pot is possible - turn it back and forth - this might clean it and restore normal operation.
  • Component or connection on CRT neck board - insufficient voltage to or incorrect biasing of the video driver for this color can result in the CRT never totally blanking. Compare voltages and signals, and swap components between good and bad channels to confirm.
  • Blanking circuit - this may be a part of the video/chroma chip or separate. Check and compare waveforms of good and bad colors to determine if the blanking pulses are making it to the video output.
There is a slight possibility that a bad CRT may result in visible retrace lines. To eliminate this possibility:
  • Disconnect the filament - all evidence of a picture, raster, and retrace lines should disappear once the filaments/cathodes have cooled (15 seconds or so. If there are still visible retrace lines, the CRT is suffering from cold or field emission from someplace (may not even be the cathode).
  • Turn down the screen (G2) control on the flyback (usually). If one color remains no matter how you set the control, again there is some kind of weird emission from the CRT. However, if white/gray retrace lines remain, the problem may be in the screen supply.
(quote ends)
You will be greatly helped if you have a schematic for your TV set, and you may need to change some parts, clean some connector contacts and/or tweak settings inside the set, so remember the original settings before you tweak them...

Good luck

3rq8 (Triarcuate)

Jul 23, 2009 | Standard (CRT) Televisions

1 Answer

KV HS29M61

1st check +200Volt are at RGB Board (mounted at CRT gun) if volts are correct, picture tube (CRT) is defective and need to be replaced. Regarding Schematic (service manaul), its available on charge basis.

Jul 31, 2008 | Sony FD Trinitron WEGA KV-24FS120 24" TV

1 Answer

Lines at top of screen

I have seen issues with complaints of raster with vertical retrace lines at the top of the picture and capacitor 2494 needs to be removed.

Jul 23, 2008 | Philips 27MT3305 27" TV

1 Answer

32 inch jvc av-32d302

Those are called retrace lines. The electron beam has to go back to the beginning of the screen as part of its raster scan. Normally it is turned down so that it can't be seen. There is a little adjustment knob on the high-voltage flyback transformer called "screen" that will hopefully adjust this for you. If that doesn't work it is an indication that the high voltage circuit is dying.
Hop Ya Fix It.

Feb 01, 2008 | Standard (CRT) Televisions

1 Answer

Slow to come on, picture flashes black, 32" SONY tv

blankenship, the "IK circuit" is blanking your screen, only "fix" is temporary, remove back of tv, and on rear right side (facing into the back of the set) you can see 2 philips type plastic screws mounted on the flyback transformer, one is focus the other is screen, do not adjust focus , turn screen control clockwise slowly until you get white retrace lines on screen, then turn counterclockwise until retrace lines disappear, this increases drive from tube to IK circuit, will last anywhere from 6 months to 18 months and then it`s replacement time, questions? e-mail me back. good luck, BMW Rider

Jan 11, 2008 | Standard (CRT) Televisions

1 Answer


do you see anything on picture doesnt mean no raster ,raster mean anything that comes out in raster with sound only mean failure in either,connection in heater which means, loose connection or some new sets declare failure in vertical be more specific ok?

May 08, 2007 | Sony FD Trinitron WEGA XBRKV-40XBR800 40"...

Not finding what you are looking for?
Sanyo DS31520 31" TV Logo

109 people viewed this question

Ask a Question

Usually answered in minutes!

Top Sanyo Standard (CRT) Televisions Experts

The Knight
The Knight

Level 3 Expert

66519 Answers

matt martin
matt martin

Level 3 Expert

1187 Answers

Donald DCruz
Donald DCruz

Level 3 Expert

17129 Answers

Are you a Sanyo Standard (CRT) Television Expert? Answer questions, earn points and help others

Answer questions

Manuals & User Guides