Author Topic: RF signal only black&white (Read 1480 times)

Wolfgang · « **on:** 2020.September.15. 16:43:43 »

While I get a good quality color picture on scart, I am unable to see color with my rf modulator. I already replaced LM1886, LM1889, TR6, C38,C39,C36 without any success. What else could be wrong?

John Fante · « **Reply #1 on:** 2020.September.16. 20:48:22 »

Just curious but did you replace anything to get RGB/scart or was that going for the start?

Wolfgang · « **Reply #2 on:** 2020.September.16. 22:09:04 »

Quote from: John Fante on 2020.September.16. 20:48:22

Just curious but did you replace anything to get RGB/scart or was that going for the start?

Scart worked right away.

Judge · « **Reply #3 on:** 2020.September.16. 23:28:42 »

SzörG wrote here that he stabilized the vibration of the RF modulator image with the R202 and put the colors back on it by tuning the C43 ...

Wolfgang · « **Reply #4 on:** 2020.September.24. 16:33:23 »

Success!
This was a hard one. I replaced the LM1889, the LM1886, all electrolytic capacitors, the 78L12, most of the transistors and a couple of ceramic capacitors in the LM1889's oscillator circuitry. In the end, changing the 4.433619MHz oscillator solved the color issue.