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hi guys, my UTMOST apologies for taking up any of your mental time with this. i got it fixed, no bad chips or anything-WHEW!
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turns out, this hakko desoldering gun is so powerful that it sucked up enough solder on a peripheral joint to make a bad connection. i had triple checked my polarities, and solder joints of the legs i was DOING, but missed one that was adjacent. i couldnt even make it with my eyes. i decided to just break down and check ALL voltages on the entire m-board; when i got some super funky voltages on a 156 chip, i traced it to a cold leg. WHEW! embarrassingly stupid, but at least its a quick fix. sigh of relief..... oh, and fyi, when i was mentioning 159 chips as drivers, i mis-spoke. meant 151, the little one-sided guys. glad i dont have to replace any of em! thanks again, guys-now please excuse me as i get occam's razor tattooed on my damn forehead. -rj 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 -----Original message-----
From: rj krohn r_j_d_2.phila@... Date: Sat, 26 Apr 2008 19:40:56 -0600 To: yamahacs80@... Subject: [yamahacs80] sorry for the questions, guys...what provides pwm/saw shapes? 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? asalways, 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. --------------------------------- Be a better friend, newshound, and know-it-all with Yahoo! Mobile. Try it now. |
