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

Ad

1 Answer

  • Level 1:

    An expert who has achieved level 1.

    MVP:

    An expert that got 5 achievements.

    New Friend:

    An expert that has 1 follower.

    Hot-Shot:

    An expert who has answered 20 questions.

  • Contributor
  • 76 Answers

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

Ad

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 there,
Save hours of searching online or wasting money on unnecessary repairs by talking to a 6YA Expert who can help you resolve this 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.

Here's a link to this great service

Good luck!

Posted on Jan 02, 2017

Ad

Add Your Answer

Uploading: 0%

my-video-file.mp4

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

×

Loading...
Loading...

Related Questions:

1 Answer

HORIZONTAL LINES ALL OVER SCREEN


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

Tip

White Raster with thin lines; Sound Ok.


White raster with retrace lines: No picture, Sound OK
(picture tube based telivisions.)

It is a common fault to occur in most of the CRT based telvisions, regardless of which brand it is. There will be sound OK, and a bright screen with thin white horizontal lines across; at about an inch space, all over the screen area. This fault may occur along with colur shades also, like blue screen with white retrace line, red screen with white retrace lines, green screen with white retrace lines. Let us take the first case. A white raster with white thin retrace line acorss the screen. These are call vertcial retrace lines technically. To make it mor understand, we have to go to some picture tube electrode details. There are three colour cathodes for a colour picture tube, Red, Blue and Green. Two girds are there called Focus and Screen. Focus grid is supplied with focus voltage which in turn determine the cocus of picture, and screen grid is supplied with screen volrage which determine the emission of the picture tube; in short. There is a final anode to all the picture tubes, which supplied with Extra High Tension voltage, can be located at the top side of the picture tube, to which the EHT voltage from LOT is connected with the help of rubber ****** and clip. Without these three voltages, EHT, Screen and Fcous, no raster will be produced. Therefore in our case, there is a raster, so, horizontal output section including Line Output Transformer [LOT] is functioning well, and as far as sound is there, tuner and video IF section are working well. In fact, all other section except, video output section is working properly.
There are three cathode points on the base card, marked as Bk, Rk and Gk. Check the voltages of these three cathodes. In our case, it will be very low or approximately equal to zero. When cathode voltages goes low, emission of the CRT increases, is the reason. There must be a voltage between 120 and 135VDC at these points. Find out the reason for this voltage drop is the next step. The video drive voltages in most TVs comes from LOT windings, after rectification and filtering. There will be one reisitor of low value, say one Ohms or so, will be connected series with this winding, in between diode and winding. Check the voltage at the cathode of this rectifier diode first. If found low replace the diode and the smoothin capcitor. The smoothing capacitor will be between 33 and 47MFD 250VDC rating. Replace both of them. If there is volatge, say 200VDC or so, check whether this voltage comes to the CRT base board or not, If not, check the conducting wire, serial resistors; if used for open. There is no chance of transistor shortage at this time as the raster we see is white. If raser we see have a specific colour predominent, that is green, blue or red, check the revalent video out transistors and replace it. It is best to replace all the three video output transisors at the same time with same batch and number.

on Apr 18, 2011 | Televison & Video

1 Answer

IM A TV TECH. I HAVE A SONY LCD KP-60XBR800 I HAVE NO RASTER. POWER OK, MENU OK BUT NO RASTER ON TUNER, TUNER VOLTS OK,CAN YOU HELP ME PLEASE. THANKS my email sergioaguirre0182@hotmail.com


check the high voltage with the screen control turned up high where there is no raster. suspect problem within the video circuit where there is no high voltage or defective picture tube.some time when the screen is black and the screen control advanced,you can see if the tv has video or vertical or horizontal problems on the screen.service the high voltage circuit if there is no raster or high voltage is seen.no raster can be caused by the no heater or filament in the CRT.---- a defective picture tube can cause many problems, such as, poor brightness ,missing colors,intermittent picture,poor focus,a single-colored raster,arching in the gun assembly,retrace lines in the picture,negative picture,chassis shutdown,noheater or filament lit and no raster to name a few.an open filament or heater can cause no picture or no raster symptom.a defective CRT can have an extremely bright screen.loose particles of the cathode element can lodge between the grids and cause an intermittent black and white picture. simply tap the ends of the CRT gun assembly and notice if the picture begins to flash off and on.---- with a leaky picture tube after turn on the raster dims and get extremely bright.a dim picture with no green in the raster can result from a bad green assembly. a heater-to-cathode short can cause a raster to change colour or a result in no raster at all.replace the picture tube if there is severe arching in the neck of CRT. excessive brightness with retrace lines and a vertical collapse to a thin line can be caused by a bad coil on the neck board of the picture tube.rejuvenate the picture tube when there is very bright green screen. check for the resistance change on the resistors of the CRT neck board for an excessively bright picture with retrace lines.excessive dust inside the CRT spark gaps within the picture tube socket can cause the very bright raster and the chassis shutdown.a defective video amp,luminance buffer,or reference transistor can cause a bright picture with retrace lines. -------- for getting any required parts to replace you can get it from www.radioshack.com or from www.partstore.com or from www.shopjimmy.com --------- thanks.please do rate the solution.thank you for using fixya.keep updated.

Sep 06, 2009 | Televison & Video

1 Answer

SONY TV PICTURE TURN GREEN WITHOUT RETRACE


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.
Thanks.

Aug 14, 2009 | Sony Televison & Video

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 http://www.repairfaq.org/sam/tvfaq.htm#tvrgbrlin )

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 | Televison & Video

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 | Televison & Video

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 | Televison & Video

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

128 people viewed this question

Ask a Question

Usually answered in minutes!

Top Sanyo Televison & Video Experts

The Knight
The Knight

Level 3 Expert

75756 Answers

Donald DCruz
Donald DCruz

Level 3 Expert

17130 Answers

 Grubhead
Grubhead

Level 3 Expert

5508 Answers

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

Answer questions

Manuals & User Guides

Loading...