No sound no picture plain raster - Sony FD Trinitron WEGA KV-21CL10 21" TV

vertical or horizontal circuit is out, new tv needed

Sound on means audio section is ok. No picture is video board problem. Pl check input cables. Or give Hdmi cable input. Disconnect all inputs switch on u should get plain raster that is only dots on screen, or blue back screen, if nothing contact authorised dealer,

Hi
Please try testing each voltage of RGB output in the small pcb attached to the CRT. If one of these voltages is missing (they are tipically almost of the same value), replace its output transistor. If all voltages are present, but very high (above 180V), please check the filter capacitor in the RGB supply voltage line near the flyback transformer (47uF/150/200V) by replacing it. It is cheap.
Please be careful when dealing with high voltage section of a tv set as capacitors may store a letal voltage. So disconnect the set from main and discharge any capacitor before dessoldering it.


If this helps you, I shall be glad.

Sully

It sounds that the 'chroma decoder' section of the IC has damaged. There is no other way than replace the IC.

The vertical ICs on this particular model have by now bad grounds. You will have to resolder this, and check any and all grounds on ICs mounted on heat sinks! Bad grounds are common and plentiful. Good Luck and thanks for asking!

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.

check your brain go for electric shock to repair your mind as well as your television

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

this sympton is characterized by the presence of red, cyan, green, magenta, blue or yellow colour in a supposedly plain white raster. proper colour reproduction cannot be expected if the raster is coloured. this symptom is caused by a poor white balance adjustment of by a trouble in the CRT, colour amplifier, color demodulation or colour output circuits. if the raster has a tint of red or cyan, check the R-Y output circuits and the first grid, second grid and cathode circuits of the red electron gun. but if you dont know anything about this, just bring it to a qualified service technician. good luck!

wepu, Buddy it sounds like you got a power supply problem. As you say the picture is all blue?? With no video or sound and the fact that the channel display is out is the first indication that i would guess this. Do you still have the owners manual that you got when you first got the set? Good, cause thats the only place i can think of where to look in case of service over in your part of the world as I did try!! Man I tryed but to no avail. No one has heard of this model but that dosent mean that it dos'ent exsit!.. If your a tech or know your way around solid state circuitry then you should have no problem finding the fault once you get a service manual from the service location in your owners manual. Now if your not a tech and a handy man ?? If I were you I wouldnt mess with the tv as theres over 25000 volts inside the set and i've seen it make a grown man cry. Man dont attempt the repair or troubleshooting if you dont have the right or proper tools and equipment!!! Good Luck