cps1 with sound problem, effects, kicks, punches and missing voices

[hatmoose]

finally after a lot of work i discovered the defect in the audio that was causing problems in the sound of kicks, voices etc. after changing oki chip, z80, all capacitors, 4 ci 5218a, ci yamaha ym2151, chip ym3012 among others, I found that the defect was simply resistor R47 (2.2k). problem solved and sound working perfectly.

Hard to find a fault like that, and resistors don’t often fail. Can’t really test them in circuit, by the time they are removed for test it’s faster to just replace them. I’ll bet it was a good moment to get this working! Nothing like that “ah” after a battle hard fought.

 

[ramosribeiro2000]

Houve algum dano visível que o fez suspeitar do resistor? Ou você estava apenas trocando peças?

checking the path of the digital sound to ci oki, I read the resistor with a multimeter, and it was altered. I did the replacement and everything started working again.

 

[ramosribeiro2000]

É difícil encontrar uma falha como essa, e os resistores não costumam falhar. Realmente não é possível testá-los no circuito, no momento em que são removidos para teste, é mais rápido apenas substituí-los. Aposto que foi um bom momento para fazer isso funcionar! Nada como aquele “ah” depois de uma dura batalha travada.

in fact, I made measurements comparing the values with another pcb that was working. when I was successful it was only joy