Hi all, this is my first post here. Awesome forum!

I working on a project RfM which has taken significant amount of my time. By far the record in my pinball life. Now that I have finished the PCB repair, I'm facing new issues described below.

Monitor:
- Hantarex Polo/2 with 15kHz horizontal scanning frequency

Graphics card:
- ATI Radeon HD8490 with modified BIOS for 15kHz support (arcadeVGA)

Problem:
Picture with the modeline provided by Nucore (in script ~/nucore/scripts/15kHz-x11.sh) sends the image right side of the screen. This is not something I can adjust using monitor's horizontal phase. Even with the full correction, the left side of the screen has black region of size ~one third of the whole screen width.

By editing the modeline, I can get the picture towards left but not enough. Looks like there's something more fundamentally wrong here. According to monitor specs, sync pulse polarity (+/-) is automatically detected.

There was no issues with the native PB2k PC setup (which, after it went down, I replaced by PC with nucore) and I really, really would love to keep the CRT - not intending to start LCD vs. CRT wars here

I'm out of ideas, anyone please?