is tda3561 can replace tda3562

[thefixer]

I have an old tv set it has tda 3562a in RGB proccessor .it is now black and white ,is there any solution for this as tda 3562a is rare .and is tda3561 can replace it with some modifications?can i enforce it it to work? thanks in advance.

[jts1957]

http://www.datasheetcatalog.com/datasheets_pdf/T/D/A/3/TDA3561A.shtml
http://www.datasheetcatalog.com/datasheets_pdf/T/D/A/3/TDA3562.shtml

[torbjorn]

Before proceeding with replacing the chip, make sure that the fault is there and not elsewhere in the tv:

-Check that the supply voltage for TDA3562 is correct (usually +12V)

-Make sure that incoming composite video seems to have correct level of the color burst and does not seem to be distorted in some way (for instance, sync clipping). There has been cases where no color was caused by a fault in the IF strip - wrong alignment or unlinearity. Check both the composite signal and the signal after the color bandpass filter (pin 4 of TDA3562).

-Make sure that the DC voltage used for saturation control (pin 5 of TDA3562) varies normally when trying to adjust saturation.

-Check that the subcarrier oscillator (crystal and various components connected to pin 26 of TDA3562) runs at correct frequency. There were some sets using TDA3562 where adjustment of the trim capacitor at the crystal was very critical.

-Check that the sandcastle pulse at pin 7 of TDA3562 is correct.

-Make sure that there is no problem with the PAL delay line or its auxiliary components - check that you have correct signal levels at pins 28, 22 and 23 of TDA3562, preferrably use a color bar signal for this test.

-Try to force the color killer to "unkilled" mode by connecting pin 5 of TDA3562 to +12V, and see if you get normal color, still no color or some kind of unsynchronized color in that mode.