ive added different ram, nvram, called "6116" its a ramtron fm1808-120-p0, the old ram was a toshiba tc5517api it held up for 2 games. no battery. all good.. untill the 3rd game it did not boot at all..

well most obvious thing to do is the last thing you changed, change it back.. so old ram in and solder wires to a battery block. and yes its boot.. but no music.. every sound works fine. just no music..

boot gives no sounds at all, and sw1 button gives a inf loop of sounds.

EDIT::::::

fixed.. i checked the diodes transistor. they ok
replaced all capacitors just because ...
the voltage regulators 1 was bad swapped all 3 for LM1458
and the toshiba tmm2016bp-15 got really hot. got that one from ebay. replaced it..

moment of truth.. all working again <3 kinda proud of myself, if someone has the same problem and find this topic.. at least i left my solution here for you