Do other keys respond normally aside from the stuck note? I had problem where 8 notes stuck. Problem was bad CMOS hex inverter on the KAS board that generated the reset pulse for the YM2660 LSI.
Like Mike suggested, replace all your CMOS, 4558's and electrolytics. Good chance this will solve your problem. Regardless, these components need to be replaced.
Gavin Curtis
ModuleMaster/Circuit Solutions Inc.
2006 S Main
Moscow, ID 83843, USA
www.modulemaster.com
Tel: 208-892-0764/888-892-0764
--- On Thu, 5/27/10, mborish_2000 <mborish_2000@...> wrote:
From: mborish_2000 <mborish_2000@...>
Subject: [yamahacs80] Re: KAS / YM26600 question
To: yamahacs80@yahoogroups.com
Date: Thursday, May 27, 2010, 11:42 AM
I wouldn't bother calibrating the thing until you replace ALL of the electrolytics and CMOS. I had several of each in mine that were failing.. ON EACH BOARD! Have you done anything to the SH board yet? I'd start looking for the stuck voice problems there. Paint brushes and plastic pens are good at finding broken connections.
-Mike
--- In yamahacs80@yahoogroups.com, "tmoravan" <moravanskyt@...> wrote:
>
> OK - I know what the problem is for the stuck voice. The difficulty is fixing it. :-)
>
> If I take voice card M4 out of the rack and move it around, the voice will either be stuck on or play normally. So, I believe one wire in that part of the harness has a break in it.
>
> Anyone want to help guess which M card connection will create a "stuck on" voice if it is broken?
>
> I can do this 2 ways - collect a probable list of wires and unsolder one at a time from a working card until I duplicate the problem or I can untie that part of the harness and pull/shake each wire...
>
> Once this problem is solved I think the only thing left to do is a calibration.
>
> --- In yamahacs80@yahoogroups.com, Csaba Zvekan <czvekan@> wrote:
> >
> > Great ! Keep up the good work . Remember the more you 'll replace the better it'll sound . Continue replacing 4000- CMOS chips . Now it would be a great to replace the chips on the SH board. See if get that stuck note checked of your list ;) .
> > Is it it always one note from the 8 you press ?
> >
> >
> > On Apr 21, 2010, at 12:11 AM, tmoravan wrote:
> >
> > > Well, I have sound again. Now back to the 'stuck on' note and another with the wrong pitch. I replaced the two 4558's and the 2 4069's on the KAS and now the YM26600 and YM26700 is behaving better. I am going to replace the 4016's and 4050's (already did the 4011's) on the KAS board...
>
[Non-text portions of this message have been removed]