Hour Glass Picture

There is an apparatus on the back of your picture tube called a yoke.This distributes your picture on your pic tube uniformly.If this or the circuits enabling it malfunction,then you will get distortion-namely an hour glass shape.Tv has to be trouble shooted.

power board problem

Probably a power supply problem.
Get a new TV...

that a pincushion problem likely caused by a failed capacitor

If there is a hour glass shape to the image but convergence is normal, there are 2 possibilities. You either have a pincushion correction problem or if the hour glass seems to be moving, it will be an open filter capacitor in the power supply.

Unless you are electronically inclined troubleshooting this issue will require a factory trained service technician. You can expect to spend $300-$400 to fix this.

If you are not familiar with electronic repairs take it to an authorized repair shop.
To get a service manual and try by yourself see link

picture is starting to curve in from the sides like the shape of an hour glass. Is the tube shot? NO. is it something less costly? YES YOUR PROBLEM is in pincushion correction circuit.call skilled tech to fix it. it will not take much time. good luck.

Big cap in the regulation ckt is bad. Depending on model could be various values, a shop could use their ESR meter to find and replace it.

You have a PIN CUSHION problem, is usually a bad capacitor or open resistor in the above cicuit. Check all the caps around the horizontal output transister for ESR leakage.

The link you posted has been deleted, so I cannot see the picture you posted. If the sides bow in like an hourglass and the red, green and blue colors are still aligned then there is a horizontal width or pincussion problem, but if the sides bow in and the 3 colors have separated and are no longer anywhere near aligned then you have a convergence problem, both of which should be serviced by someone with experience in servicing projection TV's.