CXA1465AS RGB issue, black screen only

[CharlesMoyes]

Tried RGB modding my Trinitron KV32S15 which has a CXA1465AS jungle IC and the blanking line works and makes the screen black, but no RGB signal comes through. I _am_ using the analog EXT RGB pins.

If I do not enable the blanking line, then I see a faint white ghost image of the RGB signal (enough that I can read the text on screen on my MiSTer, but nothing else):



I am stumped. I tried 2.5V and 5V into the YS blanking line, both only black screen. I have 75 ohm resistors going to ground and a 0.1 uF capacitor in series with my RGB signals. The sync signal is tied directly to composite in.

I even tried replacing the jungle chip...

[KPackratt2k]

The MiSTer outputs TTL level sync, which your TV doesn't like. Try adding a 470 ohm resistor into the sync line and see if that makes a difference.

Have you removed existing components on the patch from the closed captioning decoder to the jungle chip? If you haven't, then it could be causing interference.

[CharlesMoyes]

I removed the capacitors between the CC chip and the RGB lines. The resistor on sync line makes no difference.

[KPackratt2k]

According to your previous post in the main RGB modding thread, you had it working on a breadboard, but once you took out the breadboard and wired everything up permanently, the mod stopped working. With this in mind, here are a few suggestions:

1. Make sure you're not accidentally grounding anything that shouldn't be grounded. Use a multimeter to check for shorts in your wiring.
2. Inspect your soldering for any issues that could be causing a weak connection (e.g. bridges, cold solder joints, frayed wires, etc.).
3. If you're using quick connects (for example: JST or DuPont connectors), try bypassing those and soldering the wires together. As weird as it sounds, it's possible for bad crimps to cause problems that you wouldn't expect.
4. If you're not using heat shrink to cover the capacitors on your RGB wires, try adding it. It's possible that the exposed contacts on the capacitors are causing a short in this case.

See if any of this helps.