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If the picture is rolling down the screen the frequency of the vertical oscillator is incorrect - too high - and this may be the problem. Generally, the free run frequency of the vertical oscillator should be a little below the video rate (of around 50 or 60 Hz depending on where you live).
If it is rolling continuously without jumping, then there is a loss of sync from the sync separator or faulty components in the vertical oscillator causing it to totally ignore the sync pulses.
If it is rolling up rapidly and not quite able to remain locked, the free run frequency may be too low or there could be a fault in the sync circuits resulting in an inadequate vertical pull-in range.
On older sets, there was actually a vertical hold (and possibly even a separate vertical frequency) control. On anything made in the last decade, this is unlikely. There may be Vertical Frequency and Vertical Pull-in Range adjustments (and others) accessible via the service menu. However, if any of these ever change, it indicates a possible problem with the EEPROM losing its memory as component drift is unlikely.
As with everything else, bad connections are possible as well. You will need a schematic and possibly setup info to go beyond this.