I have a Samsung Model#CT505LD color portable which I would appreciate a
little help with.

Originally the yoke was arching.I fixed the problem only to find out that
the horizonal osc. keeps drifting.I cleaned the osc control and soldered the
printed board in and around the hor osc circuit,because I noticed if you tap
on the side of the printed board it causes the picture to be shakey.This is
most likely normal.When the osc goes off frequency you can adj the control
on the rear of the set and get the picture straight until it changes freq
again.I am wondering if soldering a cap,maybe say a (.01) across this
control will help? Any help is appreciated,very much.

Its been awhile since I worked on one of these, but if I remember
correctly the horz hold control you cleaned is the consumer adjustment
but there may be a pc pot on the board for coarse adjustment and I
beleive they cover it with glue. Also possible B+ too high .
Doug