My old HP8590a needed a new display. So I purchased a new in box unit marked as an OmniVision type. Same size, same connectors. However, it appears that the horizontal sync is not proper for the HP8590a. According to what I can find about these monitors, they handle a wide horizontal sweep frequency range. Adjustment of the horizontal sync control from end to end does not bring the display into alignment. Best I can get is a stable display but having what appears to be 5 images. I'll attach a screen shot here. Any ideas on this problem?