The splash screen on the small playfield display is always fine, but later in boot the picture sometimes turns washed out and flickers, with only flashes of the right colours. The main display is fine.

Mini display washed out and flickering after boot: power-cycle its 12 V feed

Cause: The mini display appears to lose sync when the game computer changes video mode during boot. New displays, controller boards, power supplies and VGA cables did not change it.

Checks

• Swap in a known-good mini display or controller to rule them out.
• Power-cycle only the mini display after the game has booted and see if the picture comes back.

Fix

• As a workaround, fit a reversible inline switch (or a delay relay) on the +12 V feed to the mini display, so it can be turned off for a few seconds and back on, or held off until attract mode is running, without rebooting the game.

Games

• Houdini: Master of Mystery

Source: Pinball Repair help group!! (Facebook group)