TODAS AS PEÇAS TROCADAS POREM APRESENTA ESTA FALHA ,FRONT END BOARD FAULITY
QUAL A POSSIVEL CAUSA ?
Hey man, are you positive it's the front-end card failure? They're usually very reliable! Have you tried to swap the front-end cards? If yes, did the swap change the side with the fault (persisted with the swapped card)? If yes, then I would suggest contacting Crown service center to have a replacement front-end card.
If issue persists with same channel when cards are swapped, then it's a possible output driver failure. Verify for shorted drivers and 'inspect carefully' the gate drive card!
Beware of high voltage! Discharge HV rail caps before maintenance! Caps can remain charged even when powered down!