Toshiba CX2886C/CX2885c

Syed · Joined: 17 Feb 2006 Posts: 9

My TV has almost on inch black strip on theright most of screen extending from top to bottom. I onlu understand that most probable culprit could be some capacitor in supply volatage or HOT stage. Can some one further guide me with some good tip.Thanks

Guest · Posted: Fri Feb 17, 2006 8:27 pm Post subject:

I don't know your set. Get a service manual or a circuit diagram and replace all of the filter capacitors making sure to replace the high frequency ones with low ESR capacitors.
Failing that replace the mains capacitor, it is usually the biggest one about 350 or 400 volts. Replace it with a high temperature (105 Deg.C) general purpose.
Near there you will find a switchmode transformer, with maybe the next biggest capacitor, replace all capacitors with the high temperature, low ESR variety, especially the tiny ones near the big transistor. Some will be around 20 Volts and some will be around 160 Volts.
Usually on the other end of the board you will see the line transformer, maybe a big black plastic thing with a big wire (red) going to a suctioncup on the back of the screen. Be VERY wary of this. Around here will be more filter capacitors for the line derived supplies, but maybe not close. You may have to trace the circuitboard tracks from each diode to the capacitor, replace these with high temperature (105 Deg.Celcius) low ESR capacitors.
This should make your T.V. run smootly and last alot longer. If you really like your T.V. replace the power supply capacitors on each IC, they are small inexpensive and won't take you long.

Let us know how you go. Smile

Syed · Joined: 17 Feb 2006 Posts: 9

Thankyou very much for the guidance/tips. According to your tips i have checked/changed the suspected Filter with 105 Deg Cel in the regulated supply and the fault was there then i moved to area around Ht transformer. there i have chaned4 main capacitors and now will check the small cpapcitors.
I am sorry that before i could not eleborate the fault in a correct way. Its not staright one inch strip just you can say a convex black and noisy picture on right side seems like its shifted from right to left a little bit. Tried with HOR VARiable adjustment but no success.
Meanwhile any further tip shall be highly appreciated with lot of thanks. The other problem is that i dont have the schematic of this set. So on the basis of little experience trying to understand and approaching disffrent suspected stages/components. Pl guide me further if possible.

Guest · Posted: Sat Feb 18, 2006 12:51 pm Post subject:

If I understand you right, it is a pincushion problem, bowed edges. Check the electrolytic capacitors around the pincushion circuits or 'S' correction circuits. Maybe you need an ESR meter to quickly test all electrolytics?

Syed · Joined: 17 Feb 2006 Posts: 9

Thanks for the tip regarding pincushion/s-correction. Another thing i want to tell that when i turned HOR Hold var little bit then problem is fixed but when i switch chanel, the tuning for the channel is disturbed and when i bring back the var just a little bit the, channel tuning returns and excellent picture but with that fault. You are right that must be some small capacitor is culprit. I will keep trying. Menawhile your further tip again will be appreciated with many thanks.

Syed · Joined: 17 Feb 2006 Posts: 9

I have been able to fix the fault in subject Tv with the friend's tip on EsI. Thankyou very much all of you. The fault was broken Capacitor 0.47Uf 50V just beside The Variable HOR.HOLD VARIABlE. Also Tv was suffering from small 1 inch black strip on the bottom of screen. That was due to half functional capacitor 2.2UF 50V (green Colour)also just beneath the Hor. Hold Variable- Most common in Toshiba tv mostly in Vertical stage but here it was near IC 601 by the Hor Hold Variable.
Once again lot of thanks for all of you who provided their expertise in tracing the fault.