I’ve removed some CXA too and I had the same issue. The console can run for an hour without issue, but you can’t reset the console or change game or it won’t boot anymore. 5-10 minutes later I was able to restart the console. After a while, I couldn’t get past the TMSS screen later the console simply didn’t boot anymore. DON’T REMOVE THE CXA from (some ?) PAL consoles !
I too have faint jailbars no matter what I do. I’ve done it in different ways :
Removing CXA entirely
Lifting CXA’s RGB and CSync pins
Taking +5V and GND from various places
Lifting pins from the VDP
Cutting traces on the back of the board
No matter what I do I still get a bit of jailbars. From my experience, the best place to get +5V and GND is the 7805 voltage regulator (which you can replace by a 1.5amp if you feel like it) and also twisting the +5V and GND cable together to cancel the electromagnetic field. Routing Csync as far as R, G and B as possible doesn’t seem to make a difference. Lifting subcarrier makes NO difference (Voultar actually confirmed that, I quote him : “So long as you’ve lifted the pins of the vdp, subcarrier can do whatever he wants in life”). And I wire R,G,B and Csync directly to the AV out connector under the PCB, routing the wires in the holes the RF use to occupy.
I’ve seen BayCityAnri adding some 47µf caps on the board, near the vdp, no idea why or if it’s relevant for PAL consoles etc.
So yeah, sorry guys, this message is mostly a “I’ve made the same mistakes and they are indeed mistakes” comment but at least someone might find this info while searching for it. I find that there is a lack of info on this very common mod for some reason.