[Findm-Keepm]

On many Hitachi plasma sets, if the two "digi" boards (main and sub digital boards) are not mated properly, you'll get the symptoms you describe. The connector that fails to mate is below the rubber cushion, to the right of the tuner. Pull the two boards apart and reseat the upper board, making sure the connector properly mates.

Many boards have been called bad, only to have the mating problem.

Hitachi has called this out before:

No Picture, Blue LED blinks, some LEDs on the Digi-Main remain lit. (They are supposed to go off after the power cycle).

Cycles On/Off Blue On, No Picture,
Maybe Static Picture
Auto Programming doesn't work correctly. Doesn't lock in normal channels, but does lock in unused channels.

The Digi-Main is not seated correctly into the Sub-Digital PWB.

Simply pressing on the connector won't fix.. The connector must be unplugged and then reseated.

Digi-Main must be "PUSHED" together with the Sub-Digital PWB for the connector PVM to PSM to seat correctly.
Failure to do so will result in the above symptom.
If any of the LEDs on the Digi-Main are lit, suspect a bad digi-main.

The 3300uF cap is in the Vs power supply, and could also cause the cycling problem. You might want to get a replacement - Mouser or Digi-Key should have a replacement. Check the dimensions! Diameter and length are important, and are measured in millimeters. Don't install an 85 degree cap - always (on plasma sets) use 105 degree capacitors.

Cheers,