Sanyo TV Service Mode

The procedure for entering the service mode on a Sanyo TV:

1. Press/hold "Menu" button on the TV front controls.
2. Point the remote control to the TV. Press "2" button on the remote. The service menu will appear on the TV screen.
3. Press Channel +/- to select adjustment item.
4. Press Volume +/- to adjust data/settings.
5. To exit: Press "Menu" on TV front control.

The service mode allows the TV technician to adjust picture geometry, RGB settings, TV features and hardware configurations. 

Always record the present settings before adjustment so you can return the settings should adjustments causes more problems.

It would be easier for you to set adjustments if you have a record of the factory default settings for the particular model of TV you are working on.

Philips TV 21PT128A/71R: Irregular picture size & shape problem

A TV repair problem that I had recently encountered is with a Philips 21PT128A/71R which exhibited irregular picture size and shape.

TV troubles like this usually indicates a problem with filter capacitors so I visually checked electrolytic capacitors on the main PCB.
One electrolytic capacitor on board location C2453 looked suspicious with its slightly bulging top. Checking the part using a capacitance meter, it read 3 microfarad instead of its indicated value of 680uF/35V.
 I replaced the capacitor with an available part on hand with a value of 1000uF/50V which restored normal size and shape to the picture.
The capacitor is a filter for the +25V scan-derived supply from the flyback transformer.

Samsung TV CS-29Z58MQ: three colored lines on top of picture

I have recently encountered in my repair work a Samsung Slim Fit CRT TV model# CS-29Z58MQ with a problem of three horizontal blanking lines appearing at the top edge of the screen. According, to the customer the problem started with just one line but after some time an additional two lines also appeared on the edge of the picture.
I inspected the board and tried to spot some bulging capacitors with signs of electrolyte leakage which usually cause this kind of picture abnormalities but found none.
Upon closer inspection of the solder side of the main board I saw signs of dry solder on resistors R428 (1.5 ohms, 1W) and on R413 (1ohm, 1W). These two resistors are connected in series with the Flyback transformer's 16.5V supply pin to the vertical output IC LA78045. The resistors are located at the rear edge of the main board beside the flyback transformer.
After resoldering the dry solder on the resistors the three colored lines on top of the picture disappeared.