Tips for troubleshooting keyboard module in a Roland W30?

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norlesh
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Tips for troubleshooting keyboard module in a Roland W30?

Post by norlesh » Tue Oct 14, 2014 11:07 am

Hi I just aquired a Roland W30 synth/sampler (circa 1989). Unfortunately I took the guy at his word that everything was working [oops :roll: ] only to find I have 8 dead keys. I have already stripped the key assembly down and cleaned the contacts using a cloth and friction but still the same keys remain dead [unrelated I also replaced all 29 of the tactile switches since a few were requiring undue force]. There is a sort of pattern in the way the dead keys are layed out leading me to believe the problem is elsewhere. Hoping sombody can give me some pointers on how to go about isolating the problem.

Dead keys are (assuming the leftmost key is C2):
D2,F#2,B2
D3,F#3,B3
D4,...,B4
as indicated F#4 is working just to throw a curve ball in there. All the remaining keys in the upper octaves are fine.

The keys are connected to the mainboard by three connectors:
CN3: marked T0 to T7
CN5&6: marked BR0 to BR7 and MK0 to MK7 (the BR and MK pins are interlaced BR0,MK0,BR1,...)
Each of the pins on CN3 are filtered with 100k series resistance and 100pF capacitor to ground before connecting to a chip labeled MB63H149PF-G-BND and annotated as KEY SCAN in the schematic.
Each of the CN5 and CN6 pins are similarly filtered with 17.2k resistance and 22pF capacitors before entering the same chip.

The service manual with schematic that I'm looking at is here

Unfortunately google is telling me that the MB63H149PF-G-BND was a custom gate array and hence the trail goes cold. Upcircuit of CN3,CN5,CN6 (the actual keyboard module) is not shown on the schematics and I only reassembled everything an hour ago after cleaning the contacts so am hoping to get a clue before resorting to re-dismanteling the keyboard module (anybody know a good page describing switch matrix that would have been used by Roland back then?)

so anyhow before I write any more I'll throw it over to the panel - what should I check, where should I look, how should I proceed?

thanks in advance, Shane

EagleStudios
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Re: Tips for troubleshooting keyboard module in a Roland W30

Post by EagleStudios » Tue Apr 07, 2015 5:10 pm

I have a vintage Roland W-30,,I have 3 keys in the high register that are not working,,no sounve for app 4 years ,,where could I get the unit serviced in the Detroit ,Mich area or help,,thanls :)

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