Rca tv model # 27v412t

When the picture gets smaller that means the high voltage being applied to the picture tube is failing. The flyback transformer and the horizontal output transistor are the likely parts that fail. Power supply capacitors that have domed tops are suspect too. Parts and labor for a TV that old may surpass the price of a new TV.

To adjust the data value to these adjustments, you have to enter the service mode option to your set. There is no external preset resistors [as in the old model TVs] for the new version TVs.
If you wish to get some details; check the site linked here. Pull up older posts. Surf the site with patience. http://electronicshelponline.blogspot.com/
Service mode entry, adjust and exit procedure to many popular brand TVs are given. Never forget to exit the service mode, after all adjustments have been done.
NB: Please read and understand well, the instructions to enter the service mode, before you begin. Be very careful. Note how to "EXIT" the service mode; after entering and adjusting data. This is very important.
Type in the brand name of your device, in the search box [at the top right] of the display window, and press enter to get all related posts. It will make surf easy.

To reset it into factory mode, you have to enter its service mode option. Check this link for more details about, how to enter and exit service mode, and to make adjustments. http://electronicshelponline.blogspot.com/ Pull up previous posts there, either by its left side bar, or view it in Timeslide option.

It sounds that you have to enter its service mode to adjust both vertical and horizontal position of the picture. To Philips brand TVs, entering service mode [SAM] mode, and adjusting data values there must be done cautiously. Really it is a skilled work indeed. It will be best to contact any service technician. For more http://electronicshelponline.blogspot.com/

You're discussing about the factory mode adjustments. The horizontal width adjustments will not be there. You have to adjust it by replacing certain capacitors at the horizontal output stage.

What is the brand name and model number to your TV? Provide more details please. Actually what do you want to adjust? If it is horizontal width, you have to enter its service mode to select this option. If you wish to get more details about how to enter service mode to different models of remote controls, check this link.

Get into its service mode adjustments to adjust the horizontal shift.

Visit this link to see details. It has details about how to enter service mode to several brands and models of TV sets.

electronicshelponline(.)blogspot(.com)

in name Electro-Help

Type in the link address [without brackets] into either Google Search Box or address bar to your browser, and press Enter.

Hello! You need to put your tv into service mode and adjust the horizontal and vertical size. You can find info on how to enter the service mode for some brands at epanorama.net. Good luck.

barneyluc

did u try adjusting the flyback transformer

to get into the service menu using the remote turn the volume down with the button on the front of the tv ( do not release). Whilst holdind tv vol- button press the button on the remote with a circle and three text lines for a few secs. This should let you enter the mode.