Roland Cr-80  Human Rhythm player (1991)

The Ry30 is a 12-note polyphony, digital core at 16 bitswith pads and no sound edit.
 It is mainly focused on pattern style playing (in fact it is compatible with ARRANGER card styles)

What's wrong with it?

The cr80 is not a very sought after drum machine far from tr-909 legend and seems even less interesting than its sibling R70 - but let's try this repair, as the schematics can be found (at the end of this page).

Sold as "not working" on local craiglist with stated "low output and some keys not working".
Well, It seemed easier than it looked at first glance.

bad sound output

UPPER:  very easy to open, just a screwdriver, not much. There are mainly 2 big boards: main with cpu and sound, logic and switch board. To access the lowest board and tact switch you have to remove all boards.

UPPER Ok easy one with visual inspection : sound distortion was caused by disgusting leaking capacitors near the audioboard. Check out the grey stuff on the connectors and give a good clean, seems to be quite frequent on this machine and r70. You have to replace about 10 of this value (can't remember now the value). The others are still in good values: don't touch them.
Now the cr80 has normal audio output.

Now the buttons

UPPER   Some buttons where not working, as stated. Foolishly I replaced all the tact switches, but still, some buttons were simply not recognized. I started up the test mode and realized the non- working buttons were following a logic pattern in a "cross". This sounded to me like an error on logic board. I made a test inverting the switch board from a working units, and still the same problem; the problem is in the mainboard at 100%.

UPPER The non working buttons "song play, num2, hey ride, roll snare..." are in the same line number 7 that output to CN101-> CN1 connector to the mainboard.

UPPER  Following the CN1-7 it has no signal to 17 output in a transistor array IC5.  The input of 2 was also not working. The data from D1 flowed and correctly enters into IC3-4 Hc374 octal D-type flip-flops  in pin4 but no output at pin5. Maybe we have a solution there: the HC374.

Upper: replaced the SMD flip flop, these are pretty cheap but the package was slighter bigger than the original, but it fits with no probem. Let's fire it up! but let's change also the cr2032, not soldered and finally memory reset procedure:

CR-80: Initializing the CR-80 - Restoring the Factory Settings
Use the following procedure to initialize the CR-80 and restore the factory settings:
1) Power on while holding DEL and REPEAT.
2) Press ENTER.

... and working!

All ok! smooth buttons! Soon a sample pack with exclusives cards! stay tuned


-CR80  OS EPROM not dumped yet
-CR80 User manual DOWNLOAD
-CR80 service manual 

If you like this page, just consider buying a sample pack :) 




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