开云体育

hi folks, my apologies for the incessant questions, im hoping to be in the final throes of questionland....

one of my voices just lost it's ability to make pwm and saw shapes(sine still works). i took voltage readings on the VCO chip, and the only differences from "normal" are pins 7&8. both are reading +.6, whereas a normal voice reads 1.2 or so. otherwise, all the voltages look normal.

does anyone know what provides these? is it within the IG 00153 chip, or elsewhere? as always, i cant thank you guys enough, i truly appreciate all your help- rj


---------------------------------
Be a better friend, newshound, and know-it-all with Yahoo! Mobile. Try it now.

If it can still make white noise I would suspect the Waveshaper chip
as noise goes through the filters as well.....if the noise is also
affected as well check the filters....or your output levels on the
lower front of the m card

thanks much, laurie, i appreciate it. so there's good news and bad news.

good news:
-i took voltage readings of a good cards 153 socket w/ no 153 chip in. these matched the bad cards (w/out chip) readings exactly, so i felt comfortable trying a swap out of the 153 chip, in that it shouldnt be getting any voltage levels that would be unsafe. same problem still exists w/ another, recently working 153- but im very GLAD that it is (95% chance) not a 153 chip. this would be GREAT, actually, as i went to sleep feeling like a had just burned through another extremely rare chip!

bad news:
problem still persists. i can check the output levels, but it seems unlikely(at least that its is mis-calibrated). the voice went from 100% functioning to no-waveshapes in a matter of seconds-the machine was on when it happened.(i had just recapped the voice. i checked every voices functionality after recapping each one, and this one worked initially, but when i later turned the machine on, it died).

so now, i am 99% sure that something else went down on the board. is there possibly a 159 chip that powers the 153? i had a filter problem recently that was actually sourced to a 159 chip, not the 156.

any hypotheses,as always, would be much appreciated.

Laurie Curry <laurie@...> wrote: If it can still make white noise I would suspect the Waveshaper chip
as noise goes through the filters as well.....if the noise is also
affected as well check the filters....or your output levels on the
lower front of the m card