Disklavier

Hi Ken,
I agree with you on measuring voltages (and will respond to this in your subsequent email). 
For the I/O board, I was also confused about the lighting of the LEDs. On mine, I also have LEDs 1-6 lit, with LED 7 not lit. 
-Dee
    On Friday, October 18, 2019, 09:14:03 AM PDT, 'Ken Stumpf' kennethstumpf@... [disklavier] <disklavier@yahoogroups.com> wrote:  
 
     [Attachment(s) from Ken Stumpf included below] 

  Not much progress yet, just more questions.  I tried measuring some of the voltages on the power supply and got strange results.  I may need to get a scope before I can really tell what's going on.  I studied the schematics further yesterday and found where I can test voltages closer to where they are generated so I will try that this weekend.  I still believe making sure the voltages are correct is the first step, because CPU logic will not operate properly if the 5V is too low for example.
Also I noticed on my I/O board (the big one in the bottom right of the piano) there are seven LEDs, and 1-6 are lit red on mine.  The manual for MX100A has a very confusing page about these LEDs and I cant tell if these being lit is a good or bad thing.  This is the page:

Also, not sure if you have this already but I attached the MX100A service manual that has schematics for the US model.  The MX100B one you sent has schematics for the West German model (though it has still been helpful).
Ken

 
On 9/27/2019 11:43:27 AM, 'George F. Litterst' PianoBench@... [disklavier] <disklavier@yahoogroups.com> wrote:
Here you go………