Hantarex Polo 33" 16/8 - Interlace field priority wrong?!

[SailorSat]

Hi Folks.
Well my "special edition"* Polo got new caps today. Now colors are vidid, picture is rock stable, everything is fine...

BUT...

interlaced resolutions don't work at all. They have the field priority swaped.


Any idea what is causing this?

(* Those "big screen 16/9" polos are basically 28" polos with some resistors changed by hantarex)

[Silver]

There should be a different number of equalizing pulses which specify whether to start scanning even lines or odd lines (I'm probably recalling this from PAL/NTSC signals, but I suspect it is the same for analogue RGB signals on a CRT monitor....)
 
So the problems must be:

1) Your video output is sending the wrong equalizing pulses, or the wrong video data on alternate fields. Unlikely, and would impact all monitors.

2) Your monitor is not dealing with the equalizing pulses correctly.

The Pre & Post Equalization pulses discharge the Voltage across a capacitor after the sync seperator, to ensure that the main vertical sync pulses trigger the vertical oscillator at exactly the correct time (i.e. 1/50sec in PAL, 1/60sec NTSC).

Seeing as you've just recapped, one of the caps could be duff/incorrectly installed/installed backwards.

It could be something else to do with the sync processing the monitor (sync separator etc...)


This is a rather simplified view, and probably rusty, but seems most likely to me. Have you got a service manual for the Hantarex?

[SailorSat]

i have two service manuals (for white balance and stuff), some schematics and a parts list.
guess I'll have to take a seconds look into it after all