Toshiba 329P8M Vertical Linearity Problem (Help!?)

The vertical linearity should not be adjusted - at this point in the game, at least. There is a fault in the field output stage. This will almost certainly be a defective electrolytic capacitor, particularly if the problem has been getting progressively worse. Once this has been located and replaced, there will probably be no need to carry out any adjustments.

If you don't have experience working on TVs, I would strongly recommend that you take it to a reputable repair shop, as the power supply circuitry employed in TV sets, is potentially LETHALLY DANGEROUS.

If you are OK with the safety angle, look for caps close to the field output chip's heatsink. Replace them all if you don't have the necessary test gear to check them properly.

Arfa

Some, if not many vertical deflection circuits use a push-pull oscillator setup. One side may have failed I agree to check for bad caps. If you do replace, try to find the same µf rating with a larger case/higher voltage, if the PCB layout allows it. Be sure you stay within the same error tolerance. This will put a beefier component to possibly patch a circuit weakness.

Another thing to look for is the deflection yoke, or it's control. While the yoke rarely goes bad, they do from time to time. Top and bottom deflection should be more or less equal, so if you can isolate the upper coil set from the lower, be sure they are recieving proper voltage. If not, the output can be hampered by a variety of issues, but think simple. I have run into a similar problem which was fixed by simply repairing a bad solder joint for the yoke's plug on the PCB. Any discoloration of the windings is an extremely obvious problem.

What you likely have is a bad component, not a faulty adjustment. Adjustments go out of shape very gradually as a result of wear. An instant failure or a rapid one indicates a component fault. Forget your TV's internal modes because even if you did find it, you will not find such an adjustment.

Service mode simply kills vertical deflection for aligning guns, adjusting color drives/chroma, and miscellaneous troubleshooting. All service mode will give you is your entire picture compressed to a single horizontal line on the screen. This is not what you are looking for.

If you aren't proficient with electronics, take it in to be repaired instead of meddling with controls that are already properly set. One does not tweak-out the base vertical size adjustment to make up for vertical collapse.

Also: An ESR Meter will assist you is checking the capacitors in the Vertical and Supply Circuits, replace the ones that check deficient. "Electromotive Guru" wrote in message news:448e637f$0$15474$ snipped-for-privacy@authen.yellow.readfreenews.net...