Question about Quasar SP-2725 27" TV

1 Answer

After TV warm, picture and sound go out.

We acquired an older standard type Toshiba TV that the kids use for Wii. It seems to have problems after it warms up. The screen goes black. There is also no sound when the screen goes black. The picture (along with the sound) often comes back when you hit the TV. It seems to be getting worse. Is there an easy, inexpensive fix we can try?

Posted by on

  • c_parendo Jan 15, 2009

    Thanks for the thorough response. The fix makes sense. I will try it this weekend when I have more time.

×

1 Answer

  • Level 3:

    An expert who has achieved level 3 by getting 1000 points

    Superstar:

    An expert that got 20 achievements.

    All-Star:

    An expert that got 10 achievements.

    MVP:

    An expert that got 5 achievements.

  • Quasar Master
  • 5,568 Answers

This could be due to what we techs call a 'cold solder joint.' The mere fact that temperature and whacking the set seems to help, reinforces this diagnosis.

There are a number of points on the circuit board that get quite hot and solder joints can fail from metal fatigue; the swelling and shrinking of the joint until the copper leads and solder (tin/lead) separate.
To inspect the main board, please pull the plug from the AC and let the unit sit overnight to eliminate the chance of a nasty shock, then remove the back (~6-10 screws).
If you have a digital camera make a couple of pix of the guts from different angles unless you trust your memory, then pull plugs from the board (marking them in some way is best).
The heavy-looking lead attached to the picture tube (CRT) has a spring clip that needs to be compressed from the side to free it, otherwise the various cables can be removed by unplugging.
You should have a quality soldering iron for this, NO GUN! These are too hot and may cause the traces on the PC board to lift. The soldering tool needn't cost a hundred bucks but should be designed for electronics work, preferably with an iron-plated copper tip; these stay clean better and are easier to tin. The solder should be some designed for electronics use (no acid!) and with a rosin core that serves to clean the surfaces to solder. In the same place, pick up some 'solder wick' or if they have cheap solder suckers, any of these should be good enough unless you are planning on doing this for a living. The total cost will be under ~ $20 US.   
You should have a cellulose sponge, wetted and wrung out so you can often clean (wipe briefly) the tip and put fresh solder on it.
Now you are kinda prepared (40+ years experience is better) to look for solder joints on the underside of the board. If a joint, especially a larger one (they are more sensitive) that appears dull or even cracked around the pin coming through from the other side, use the wick or ****** to remove the old solder, clean the tip, flow some of the new solder into the joint. It should look shiny and obviously flow onto the pin and the board joint. Try to keep the length of time short; otherwise, the trace may lift from the board. If it does, use something non-metallic and heat proof to hold it down, reheat the solder joint briefly and press the trace down onto the board again with the tool.
If you cannot identify any specific joint that might have failed, I would recommend you do all except the smallest ones (called shot-gunning) so you have some chance of hitting the right one.
You can do this!  Just think, you've learned a new skill! Unfortunately, it isn't one particularly valuable anymore since we now just throw stuff away instead of trying to compete with Chinese child-labor.     

Posted on Jan 15, 2009

Add Your Answer

Uploading: 0%

my-video-file.mp4

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

×

Loading...
Loading...

Related Questions:

1 Answer

Toshiba tv, turns on with sound but no picture.


Check and replace damaged component/s at its horizontal scan output section circuit. Check the LOT (Line Output Transformer) too for damage. Replace the horizontal scan output transistor. Check the input voltage to LOT. If the voltage is absent check the feeder resistor; if any. If you wish to get some details; check the site linked here. Surf the site with patience. Pull up older posts.
http://electronicshelponline.blogspot.com/
Type in the brand name of your device, in the search box [at the top right] of the display window and the Search will start at once as you type in, and will show you all the related posts. It will make surf easy.

Feb 22, 2015 | Toshiba 36A40 36" TV

1 Answer

Rca tv has sound no picture


Check its line output transofrmer [LOT] and related components. Replace them

Apr 22, 2012 | RCA Standard (CRT) Televisions

1 Answer

Burning smell Toshiba tv/dvd


NO problems,Who care,might burning dust and grease that the smell.Take it aparts for a good clean with a air compressor.

Mar 02, 2010 | Toshiba 32A33 32" TV

1 Answer

Every thing works except the sound


press mute on the remote control

Jan 25, 2009 | Toshiba 32A33 32" TV

1 Answer

No picture


Try a "hard restart"', which simply means unplugging the power cord of your TV, and replugging it after 4 hours have passed. This technique helps to reprogram the electronics of your TV.
Hope this suggestion works for you.

Jun 05, 2008 | Mitsubishi VS-60607 TV

3 Answers

Panasonic CT-32SL14 flat screen tv stopped working


We played Wii sports and fit for few hours than tv started to flicker and change colors to green and black and white. We shut down Wii and not TV screen doesn't show any picture. The power is there and the sound... but the screen is just blue. Any one experienced anything similar?

May 20, 2008 | Panasonic CT-32SL14 32" TV

1 Answer

Toshiba 36AFX61


Just Connect signal to tv and run autoprogram. Or use video input jacks from converter to tv ( yellow,white and red video in ) and select tv/video on tv pannel front ( don't need remote control) I hope this work for you.

May 11, 2008 | Toshiba 36AFX61 36" TV

1 Answer

Picture problem


Since it is 9 years model definetely loose contact and flux corrosion is there in wire connector and pcb also. Make one general service. Prolem solved.

Aug 23, 2007 | Toshiba CF35F50 TV

3 Answers

Set needs to be slapped to get a picture


TV's need a good slap once in a while to set them right! Just kidding. Sounds like you have a bad connection that once the set is warm it mends itself. Have a technician look at it.

Apr 18, 2007 | Toshiba CF27H50 TV

Not finding what you are looking for?
Quasar SP-2725 27" TV Logo

258 people viewed this question

Ask a Question

Usually answered in minutes!

Top Quasar Standard (CRT) Televisions Experts

The Knight
The Knight

Level 3 Expert

68223 Answers

Radames Pagan
Radames Pagan

Level 3 Expert

195 Answers

Jaime Hernandez

Level 3 Expert

2267 Answers

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

Answer questions

Manuals & User Guides

Loading...