[sdiy] roland tr606 clock issues

Travis Thatcher recompas at gmail.com
Tue Jun 15 20:17:10 CEST 2010

I"m thinking its a logic issue.  The din jack seems ok, since when i
plug the cable in, the clock is switched off until it gets a proper
signal. Oddly enough however, the int/ext din clock switch doesn't do
anything, its like it is stuck in external mode when the din cable is

I wonder if this issue is at all related to the bank select switch not

anyway, here's a service manual I've found.

I'm guessing ic1, the schmitt trigger may be to blame? or could it be
a bad transistor somewhere?

I did notice that this 606 has seen better days. When I took it apart
I found that there's several jumper wires on the board because of
traces that have gone bad as well as some re-soldering of the traces
on the board.  at least the cpu runs and the other controls seem

Thanks for the help!


On Tue, Jun 15, 2010 at 2:10 PM, Graham Atkins <gatkins at blueyonder.co.uk> wrote:
> I'm sure someone had a similar problem a while back. As many of the switches
> are multi-function depending on if you are pattern writing etc they are
> probably
> encoded in some way, the LED will show the status depending on mode. Could
> be a logic fault. Need to see the circuit.
> Graham
> On 15 Jun 2010, at 06:10, Travis Thatcher wrote:
>> I checked my cable, and all 5 pins are connected.  I'm going to guess
>> its a bad transistor somewhere or perhaps a bad chip? any ideas? like
>> I said, the start/stop button will turn the led on and off, but not
>> start and stop the pattern. i check the ribbon cables and the wires
>> running from the switch board to the main one and they seem fine.
>> -Travis
>> On Mon, Jun 14, 2010 at 9:36 AM, Travis Thatcher <recompas at gmail.com>
>> wrote:
>>> I completely forgot about that! i need to check my cable to make sure
>>> all 5 pins are wired.  still, doesn't solve the clock problems of the
>>> device running on its own.


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