Problem with TDA9160A (Old TV IC) no colour

[reinoso]

Hello,

I have designed a circuit with this IC. The purpose of the circuit is to convert NTSC CVBS signal into RGB.

Well ... the problem is there is no colour at the output (however, I get B/W perfect image). I have programed the i2c registers with the following config:

- Input = CVBS1
- Phase time constant = auto
- crystal = 1x3.6mhz
- Field frequency = auto
- interlace
- normal mode
- phi one loop closed
- auto search
- PAL/NTSC
- Reference crystal

Datasheet: http://www.datasheetcatalog.org/datasheet/philips/TDA9160.pdf

When I read the status register, I always get "colour OFF".

I have tested two different 3.57mhz crystals ... with no results. Have tested also several capacitors values in series with the crystal (18pF, 100pF, 220pF), even a trimmer (0-30pF), but no results again.

Schematic

**broken link removed**

thanks in advance