Thanks, the guy who own the synth has finally decided to get it back, so I didn't have the chnace to do that finally. --- In kawai_sx210@yahoogroups.com, "Travis Shire" <boardjunkie@t...> wrote: > Try clipping this ic's supply voltage pin (do it so it can be resoldered > if need be) and see if the v rail returns to normal. If so, you found the > problem. > > > > ----- Original Message ----- > From: gil_we > To: kawai_sx210@yahoogroups.com > Subject: [kawai_sx210] Re: OT: Juno 106 doesn't start > Date: Sat, 02 Jul 2005 09:56:48 -0000 > > Found one 80017A that's hot as hell !! > > It's the first one from the right. I wonder if the short is in the > chip itself or is caused by another component that interacts with > it... > > > > > > > > --- In kawai_sx210@yahoogroups.com, "Travis Shire" <boardjunkie@t...> > wrote: > > The +15v rail drops *when* you plug in a connector? You're not > doing this > > with pwr on are you? NEVER do that.....ever. There's a ton of CMOS > ic's > > in there that will be ruined from the voltage spikes created when > > plugging/unplugging a connector with pwr on. You've already found > > incorrect voltages....you seem to know what they should be. There > may be > > 3 terminal regulators for the +/- 15v (this powers the audio op- > amps) > > such as 7815 (+15v) and 7915 (-15v). If that's the case, one pin is > v in, > > one pin is v out (15v regulated) and one pin is gnd. > > > > Make sure the +5v digital rail is at 5v (or very close, within a > 10th of > > a volt) with no ripple. All logic functions will need it to be > stable for > > the CPU to do *anything*. > > > > Best track down a schematic for the power supply pcb and trouble > shoot > > each rail. > > > > There is also the possibility that something is dragging a v- rail > low due > > to a short. Op amps can do this....look for one that gets > abnormally hot > > in a few seconds after power up. > > > > Do some detective work and let us know what you come up with. > > > > > > > > ----- Original Message ----- > > From: gil_we > > To: kawai_sx210@yahoogroups.com > > Subject: [kawai_sx210] OT: Juno 106 doesn't start > > Date: Fri, 01 Jul 2005 07:21:00 -0000 > > > > When turning it on, all leds lite up, no sound. > > > > I checked the voltages and instead of 15v there are only 3.7v > > measured > > at the PS. I found that the 15v voltage drops as you connect the > main > > module board to the PS. If disconnected from the PS the system > runs > > on > > the required 15v. > > > > Any suggestiopn where to begin checking the module board? > > > > > > > > > > SPONSORED LINKS > > Music sampler Music synthesizers Synthesizer music > > Synthesizer Sampler > > > > > ------------------------------------------------------------------ > -- > > > > YAHOO! GROUPS LINKS > > > > * Visit your group "kawai_sx210" on the web. > > > > * To unsubscribe from this group, send an email to: > > kawai_sx210-unsubscribe@yahoogroups.com > > > > * Your use of Yahoo! Groups is subject to the Yahoo! Terms of > > Service. > > > > > > > ------------------------------------------------------------------ > -- > > > > -- > > ___________________________________________________________ > > Sign-up for Ads Free at Mail.com > > http://promo.mail.com/adsfreejump.htm > > > > ------------------------------------------------------------------ -- > > YAHOO! GROUPS LINKS > > * Visit your group "kawai_sx210" on the web. > > * To unsubscribe from this group, send an email to: > kawai_sx210-unsubscribe@yahoogroups.com > > * Your use of Yahoo! Groups is subject to the Yahoo! Terms of > Service. > > > ------------------------------------------------------------------ -- > > -- > ___________________________________________________________ > Sign-up for Ads Free at Mail.com > http://promo.mail.com/adsfreejump.htm
Message
Re: OT: Juno 106 doesn't start
2005-07-07 by gil_we