Hi, i am always stuck with an 1fz that i resurrected from dead (it was in watchdog mode), i swapped z80 and it worked but sound stopped working again. i desoldered and socketed ram11, sm1 and ym2610, when i use its original ym2610 i have expected c3, actual d3 with z80 dead/comm. error but when i use a new ym2610 the screen became green when i press start+pause keeping D pressed.