If picture seems to be out of focus, try to adjust focus control on the Line Output Transformer [LOT] and try to make it right. If it does not help you, replace the picture tube base socket. This socket can be located at the base card of the picture tube. If you fail to adjust the focus, by adjusting the focus pot control at the LOT; the LOT is defective, and should be replaced with same type and number. Check the main secondary voltage [which will come to the range of 95VDC to 135VDC]. If this voltage is not sufficient enough, this fault may occur. If this voltage is found very low, [refer to the schematic diagram of the set, to get the exact voltage level], replace the smoothing capacitor for this voltage. This capacitor may vary to a value of 220MFD 160VDC to 330MFD 160VDC.