Panasonic 27" Squashed Picture

ESR meter check the electrolytic capacitors in the vertical output stage and ramp generator. Optional to simply jump the capacitors while tv is running on an isolation transformer to find the culprits.

By the way you are asking, you'd be best off to give the set out for proper service. The set has to be properly troubleshooted to determine the cause. This would require the proper training and troubleshooting tools to service. There are serious safety issues when servicing TV sets.

Jerry G.

The

is a great resource of electronics repair information and explains safety procedures, including how to discharge capacitors. The most likely capacitor hazard is the picture tube itself, so don't unplug the thick cable going to the rubber cup on the side of the tube. Also don't ignore the hazard of the fragile glass picture tube shattering because TVs tip over very easily, usually forward.

A local library may carry Sams Photofacts (no apostrophe in "Sams") repair manuals, but Panasonic sells factory repair manuals for very low prices.

Your TV may have a bad capacitor in the main power supply, but far more likely a capacitor in the vertical output section is going bad. To find the vertical chip, trace the 4 wires leading from the picture tube yoke (not the small circuit board that plugs into the end of the tube) to the main circuit board, and look up the part numbers of the chips near those wires by searching

or by simply Googleing. I would replace all the electrolytic capacitors connected to the vertical chip, but if you need to replace only one, very likely you want the ramp generator timing capacitor. Any new capacitor must be rated for at least as much voltage as the original, and its capacitance value (uF) should be within 20%. Try to get caps rated for 105 Celcius, not the usual 85C. Watch polarity because installing a polarized cap backwards can cause it to short and go bang.

I hope your desoldering skills are good because you don't want to damage the circuit board. Use a 30-40W iron (40W is better) with a very clean tip and narrow (.05-.08" wide) copper desoldering braid. Cut the braid right after it absorbs solder. If the solder won't wick up completely, then you either need a more powerful iron (don't exceed

50W), a cleaner tip, or should add fresh 60/40 tin/lead solder and start over. Practice on a junk board first.

By far the biggest shock hazard in any TV is the mains filter capacitor, potentially instantly fatal if discharged across the body. The CRT charge is a minor inconvenience by comparison, an unpleasant whack/jolt.

Dave