If the picture was shrinking from side to side there would be a problem with horizontal deflection. If the picture was shrinking top to bottom, then problem is in the vertical deflection circuits. 99 out of 100 times this problem is caused by one or more leaky electrolytic capacitors. First thing to do is identify the portion of the board that is the horiz. or vert. deflection if there are a large number of caps on the circuit board. Usually it will be the cap(s) that are of high voltage value.(anywhere between 50 to 350 volt caps). A schematic is extemely helpful, but not everyone can make out a schematic enough to find the caps and affected circuit. If you have an ESR cap meter, you simply put the leads across the cap and see if they are dry. Usually their capacitance is 50 ESR ohms and higher if they are. If there is a low number of caps, then go through each one by one. If you have no ESR meter, then you have to pull them from the circuit and find some kind of capacitance meter to see if their capacitance is within spec.(usually 10%+ or -). If you have no meter at all, I guess I would change the high voltage value caps out with new ones. That would be shooting in the dark at best, though. I admit, I have done it on several occasions and been lucky. If your TV went out with a pop or something, that could be another problem entirely. That could be a regulator transistor or maybe just a fuse that blew. If it does NOT come on and shrink to nothing, or shrink to a line, then there is probably something else wrong with the unit. Feel free to email me if you have any more questions.

Reply